study of natural products as leads for new pharmaceuticals for the various class of drugs

Prepared By:- Subham Kumar Vishwakarma
(Shubhamkumarvishwakarma7@gmail.com)
Guided By:- Dr. S Raja (GITAM Institute Of Pharmacy)
CHEMISTRY OF NATURAL
PRODUCTS (MPC-104T)

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CHEMISTRY OF NATURAL PRODUCTS (MPC-104T) By Subham Kumar Vishwakarma
CONTENT: -
• Drugs Affecting the Central Nervous System: -
Morphine alkaloids: -
1) BIOLOGICAL SOURCE
2) FAMILY
3) STRUCTURE AND IUPAC NAME
4) ISOLATION PROCEDURE
5) STRUCTURAL ACTIVITY RELATIONSHIP
6) PHARMACOLOGICAL INFORMATION AND USES
7) FORMULATION PRODUCTS
• Anticancer Drugs: Paclitaxel and Docetaxel, Etoposide and Teniposide
• Cardiovascular Drugs: Lovastatin, Teprotide and Dicoumarol
• Neuromuscular Blocking Drugs: Curare alkaloids
• Anti-malarial drugs and analogues
• Chemistry of macrolid antibiotics (Erythromycin, Azithromycin,
Roxithromycin, and Clarithromycin)
• β - Lactam antibiotics (Cephalosporins and Carbapenem)

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Drugs Affecting the Central Nervous System:
Morphine alkaloids
BIOLOGICAL SOURCE:
Morphine is a naturally occurring substance extracted from the unripe but fully grown
capsules of Papaver somniferum.
FAMILY: - Papaveraceae
STRUCTURE AND IUPAC NAME: -
(4R,4aR,7S,7aR,12bS)-3-Methyl-2,3,4,4a,7,7a-hexahydro-1H-4,12-
methanobenzofuro[3,2-e]isoquinoline-7,9-diol
ISOLATION PROCEDURE: -

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• The method is to extract from the crushed plant with diluted sulfuric acid,
which is a stronger acid than meconic acid, but not so strong to react with
alkaloid molecules.
• The extraction is performed in many steps (one amount of crushed plant is
extracted at least six to ten times, so practically every alkaloid goes into the
solution).
• From the solution obtained at the last extraction step, the alkaloids are
precipitated by either ammonium hydroxide or sodium carbonate.
• The last step is purifying and separating morphine from other opium alkaloids.
CHEMISTRY INTERPRETATION DATA:
STRUCTURAL ACTIVITY RELATIONSHIP:
• Replacement of phenolic hydroxyl into –OCH3/-OC2H5 will make the
morphine less analgesic and cough suppression will also takes place.
• Replacement of alcoholic hydroxyl with –OCH3 makes the compound 5 times
more active.
• Replacement of alcoholic hydroxyl with -OC2H5 makes the compound 2.4
times more active than morphine.
• Replacement of alcoholic hydroxyl with –OCOCH3 will also activates the
compound by 4.2 times.
• Replacement of alcoholic hydroxyl with ketone group inactivates the
compound and makes it lesser active.
• By hydrogenation of alicyclic unsaturated linkage, activity increases by 1.2
times.
• On replacement of the methyl group from tertiary nitrogen by hydrogen atom,
activity decreases.
• On replacement of N-CH3 by NCH2CH2Ph, activity increases by 14 times.
• When the methyl group of tertiary nitrogen replaced by N-
allyl/methallyl/propyl, the compound so formed acts like the Morphine
antagonist.
• When the methyl group of tertiary nitrogen replaced by N(CH3)2 Cl–,
compound have curare action and it do not possess any analgesic activity.
PHARMACOLOGICAL INFORMATION AND USES:
MECHANISM OF ACTION:

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• Morphine acts as opioid receptor agonist in the brain.
• Thereby, it shows action by coupling with calcium channels with the help of G
proteins.
• This results in producing the calcium channel antagonist properties of morphine.
• Other than this, Morphine also binds to postsynaptic receptors and hyperpolarizes
postsynaptic neurons.
• All these actions together help in reducing the pain signals to the CNS.
USES:
• For the reduction of both, acute and chronic pain
• In reducing the symptoms of shortness of breath.
• Also used as an opiate substitution therapy.
• Most powerful analgesic used in cases of severe pain as post-operative pain,
bone fractures, cancer patients & in cases of angina.
• Remedy in convulsions.
• Precede the use of anesthetics to increase their efficacy
• Used as an antagonist for poisonous effects of other alkaloids as strychnine,
atropine, Physostigmine.
FORMULATION PRODUCTS:
• Arymo ER, Tablet, film coated, extended release, 15 mg/1, Oral.
• Avinza, Capsule, extended release, 90 mg/1, Oral.
• Astramorph, Injection, 0.5 mg/1mL, Epidural; Intrathecal; Intravenous.
Anticancer Drugs:

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1.PACLITAXEL
BIOLOGICAL SOURCE - TAXUS BRAVIFOLIA
FAMILY- TAXECEAE
CHEMICAL CONSTITUENT – Taxol, paclitaxel, docetaxel
Dried stem bark of Taxus Brevifolia, Family: taxaceae. Syn. Pacific Yew (western) The
Taxaceae is a small family with one main genus, Taxus, which has an ancient reputation
as a toxic and magical plant. The yew tree was used in ancient Greece and Rome to
produce weapons. An alkaloidal Taxus fraction, which was named “taxine” by Lucas
(1856), is highly cardiotoxic and has been implicated in many stock poisonings and
human poisonings.
STRUCTURE & IUPAC NAME
4α,10β-bis(acetyloxy)-13α-[(2S,3S)-3-benzamido-2-hydroxy-3 phenylpropanoyloxy]-
1,7β-dihydroxy-9-oxo-5β,20-epoxytax-11-en-2α-yl benzoate
ISOLATION OF TAXOL
The initial isolation and characterization of paclitaxel proved particularly difficult
because of its very low natural abundance in T. Breuifolia bark (although this was the
best-known source, the isolated yield was only 0.02% w/w, equivalent to 650 mg per
tree), the poor analytical data obtained from the purified compound, and the failure of
paclitaxel to give crystals that were suitable for X-ray analysis.
ISOLATION PROCEDURE:
Step-1:
• Washing raw plant material using deionized water.
• The temperature of water is in the range of 20 to 25°C, and duration of the

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process is 3 hrs.
• Then, the water is removed along with all water-soluble impurities.
Step-2:
• Extraction with an organic solvent.
• The adequate solvents for this extraction are alcohols (methanol), ketones
(acetone) and their mixtures.
• In cases where a mixture is used, the volume ratio in the mixture is about 1:1.
• The obtained extract is filtered to remove deposits, and then transferred to a
double walled tank, where the water temperature is in the range of 65–70°C.
• The organic solvent is then removed by distillation. The remaining solution is
drained into another tank. Because there is residual water, that solution is a non-
concentrated extract.
Step-3:
• Isolation of biomass from the solution obtained in the previous step.
• The extract is diluted in methanol and water and then salted out to precipitate
the biomass.
• Sodium chloride is quickly added to the extract under heavy stirring.
• The formed biomass is separated from the solution by filtration or by
centrifugation.
• The separated biomass, which is wet, can be dried by ventilation or
lyophilization.
Step-4:
• Removal of the resin and natural pigments by treating the dried biomass with
mixture of acetone and hexane.
Step-5:
• Chromatographic purification of a solution of the paclitaxel-enriched oily phase
and crystallizing the purified solution obtained by chromatography.
• In this procedure, the paclitaxel-enriched oily phase is first mixed with silica gel
and dried under ventilation.

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• The silica gel coated with the oily phase is loaded onto a chromatographic
column containing the same type of gel.
• The purification is con ducted using the mixture comprising 35% of acetone
and about 65% hexane.
• The fractions containing paclitaxel obtained by chromatography in the
preceding step are evaporated to dryness and put back in an acetone solution.
• Then, the paclitaxel is crystallized by adding from 3 to 4 volumes of hexane to
the acetone solution
PHARMACOLOGICAL INFORMATION: -
• Horwitz discovered that the compound prevented cell division by a unique mode
of action. In contrast to the antimitotic vinblastine and podophyllotoxin analogs

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which prevent microtubule assembly, paclitaxel inhibits cell division by
promoting assembly of stable microtubule bundles, which leads to cell death.
• Paclitaxel got bound with beta-subunit of tubuline protein.
• This leads to the locking of the microtubules at their places and cell cannot use
the microtubules in an effective way.
• This negatively affects the cell’s transportation mechanism and also inhibit the
mitosis of the cell.
• Further, paclitaxel binds with stopping protein Bcl-2 and induces apoptosis in
the cell.
USES: -
• The main use of docetaxel is the treatment of a variety of cancer after the failure
of anthracycline based chemotherapy.
• OVARIAN, PROSTATE & COLON CANCER
• LUNG CARCINOMA
• GASTRIC & CERVICAL CANCER
CHEMISTRY INTERPTRETATION DATA:
• UV-VISIBLE INTERPRETATION DATA: In the developed method,
PBS (phosphate buffer pH- 7.4) and methanol were used as solvents. The λ max
was determined to be 230 nm. The linearity concentration range was 2-20μg/ml
with the correlation coefficient of 0.993. The percentage recovery for PTX was
found to be 99.82 to 100.48%.
• IR INTERPRETATION DATA: Powders of paclitaxel, PLDLA,
PLDLA microspheres, PLDLA microspheres loaded with paclitaxel were
examined by FTIR, using a spectrophotometer model ATR-FTIR Perkin-Elmer
100S. Samples were taken in a KBr pellet, and scanned in the IR range from
600 to 4000 cm–1
.
• MASS INTERPRETATION DATA: -?
STRUCTURAL ACTIVITY RELATIONSHIP:
• Phenyl moieties at C-3’N, C-3’ and C-2 positions are not necessary for the
cytotoxicity and the anti-mitotic activity of the drug.

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• Replacing the phenyl groups with t-butyl groups can increase the activity of the
drug.
• Replacing the phenyl groups with t-butyl groups can increase the potency to
induce apoptosis in the cell. It can also increase the bioavailability of the drug.
therefore, this type of modification was considered as the best modification of the
drug paclitaxel.
• Modification at the C-3 position of the C-2 benzoate with CN, N3, CH3O, and Cl
increases the anticancer activity against P-388 cell line.
FORMULATION PRODUCTS: -
NAME DOSAGE STRENGHT
Abraxane Injection, powder, for suspension (IV) 5 mg/ml
Paclitaxel Injection (IV) 6 mg/1mL
Onxol Injection, solution, concentrate (IV) 6 mg/1mL
PACLISAL 100 Injection IP (IV) 100mg/16.7mL

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2.DOCETAXEL
BOTANICAL SOURCE: Docetaxel is of the chemotherapy drug class; taxane,
and is a semi-synthetic analogue of paclitaxel (Taxol), an extract from the bark of the
rare Pacific yew tree, Taxus brevifolia.
FAMILY- TAXECEAE
1,7β,10β-trihydroxy-9-oxo-5β,20-epoxytax-11-ene-2α,4,13α-triyl-4-acetate 2-benzoate
13-{(2R,3S)-3-[(tert-butoxycarbonyl) amino]-2-hydroxy-3-phenylpropanoate}
• Docetaxel got bound with beta-subunit of tubuline protein.
• This leads to the locking of the microtubules at their places and cell cannot
use the microtubules in an effective way.
• This leads to the locking of the microtubules at their places and cell cannot
use the microtubules in an effective way.
• Further, Docetaxel binds with stopping protein Bcl-2 and induces apoptosis in
the cell.
USES:
Docetaxel is used for the treatments of:
• Breast cancers
• Non-small cell lung cancer
• Advanced stomach cancers
• Head cancers
• Neck cancers
• Metastatic prostate cancers

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• Small cell lung cancer
• Ovarian cancer
• Bladder cancer
• Pancreatic cancer
• Soft tissue sarcomas
• Melanomas
• UV-VISIBLE INTERPRETATION DATA: The UV-visible spectrum
obtained by scanning the 10μg/ml of docetaxel recorded between 200 nm to 400
nm. It was observed that docetaxel shows the characteristic peak at 229nm and
thus it was selected as the analytical wavelength. Analytical method
for docetaxel was developed and validated by UV spectrophotometrically
in acetonitrile. The high correlation coefficient in the above solvent indicated that
absorbance and concentration of the drug was linearly related. Beer’s law was
found to be obeyed in the range of 5 to 45µg/ml for docetaxel in acetonitrile.
STRUCTURAL ACTIVITY RELATIONSHIP: -
• Phenyl moieties at C-3’N, C-3’ and C-2 positions are not necessary for the
cytotoxicity and the anti-mitotic activity of the drug.
• Replacing the phenyl groups with t-butyl groups can increase the activity of
the drug.
• Replacing the phenyl groups with t-butyl groups can increase the potency to
induce apoptosis in the cell. It can also increase the bioavailability of the drug.
therefore, this type of modification was considered as the best modification of
the drug paclitaxel.
• Modification at the C-3 position of the C-2 benzoate with CN, N3, CH3O, and
Cl increases the anticancer activity against P-388 cell line.
FORMULATION PRODUCT: -
DOCESAL Powder (IV) 80mg/2mL
Docefrez Powder (IV Infusion) 20mg/mL after reconstitution
Docetaxel injection IV infusion 20mg/mL

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ETOPOSIDE
BOTANICAL SOURCE: The dried Rhizomes and roots of Podophyllum
Hexandrum. [Etoposide is a semisynthetic derivative of podophyllotoxin from the
rhizome of the wild mandrake (Podophyllum peltatum). More specifically, it is a
glycoside of podophyllotoxin with a D-glucose derivative.]
FAMILY- Barberidaceae
CHEMICAL CONSTITUENT - Prenylated flavonoids, flavonoid glycoside, and
labdane diterpenes.
STRUCTURE & IUPAC NAME-
4'-demethyl-epipodophyllotoxin 9- [4, 6-O-(R)-ethylidene-beta-D-glucopyranoside],
4'- (dihydrogen phosphate)
• Extract 4gm powder Podophyllum peltatum root by stirring and heating with
100ml of ethanol for about 10 minutes.
• Cool and filter the mixture
• Re-extract the residue with further 100ml of ethanol
• Combine the extracts and evaporate to about 20ml
• Add the ethanolic solution into 100ml of water, and extract three times with 50ml
ethyl acetate.
• Combine the extract and evaporate to dryness
• Isolate the Podophyllotoxin by preparative TLC
• Crystallization at 0℃ for several days

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➢ DNA topoisomerase is inhibited by Etoposide.
➢ Due to this, DNA re-ligation is inhibited.
➢ Inhibition of DNA re-ligation causes critical errors in DNA synthesis at the
premitotic stage of cell division
➢ This leads to apoptosis of cell.
OR
Mechanism of action
The main effect of etoposide appears to be at the late S and early G portion of the cell
cycle in mammalian cells. Two dose dependent responses are seen at high
concentrations (10 mcg/ml or more), lysis can be observed of the cells entering mitosis;
at low concentrations (0.3to10 mcg/ml), the cells are inhibited from entering the
prophase. Microtubule assembly is not affected. The predominant macromolecular
effect of etoposide seems to be the rupture of the double strand by an interaction with
DNA topoisomerase II or by the formation of free radicals. Etoposide has been shown
to cause metaphase arrest in chick fibroblasts.
USE: - Etoposide is used for the treatments of:
➢ Testicular cancer
➢ Bladder cancer
➢ Prostate cancer
➢ Lung cancer
➢ Stomach cancer
➢ Uterine cancer
➢ Hodgkin’s lymphomas
➢ Non-Hodgkin’s lymphoma
➢ Mycoisis fungoids
➢ Kaposi’s sarcoma
➢ Wilm’s tumor
➢ Rhabdomyosarcoma
➢ Ewing’s sarcoma
➢ Neuroblastoma
➢ Brain tumors

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• Introducing the hydroxyl group at 2- and 4- positions of phenyl ring can
increase the selectivity and potency of the drug.
• Compounds without the hydroxyl groups are found to be less active.
• Introduction of hydroxyl groups at ortho and para groups at 2-phenyl ring
showed stronger topo II inhibitory activity
• Compounds having hydroxyl groups at meta position showed potent topo II
inhibitory activity and strong antiproliferative activity.
• Overall, the hydroxyl groups at ortho and meta positions are important for the
activity of the drug.
Etoposide Injection USP, 20 mg/mL, is supplied as follows:
NAME STRENGTH CONTAINER TYPE/USAGE
NDC 16729-114-31 100 mg/5 mL Sterile Multiple Dose Vial
NDC 16729-114-32 250 mg/12.5 mL Sterile Multiple Dose Vial
NDC 16729-114-08 500 mg/25 mL Sterile Multiple Dose Vial
NDC 16729-114-11 1 g/50 mL Sterile Multiple Dose Vial
Store between 20° to 25°C (68° to 77°F). See USP controlled room temperature.

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TENIPOSIDE
BOTANICAL SOURCE: The dried Rhizomes and roots of Podophyllum
Hexandrum. [Etoposide is a semisynthetic derivative of podophyllotoxin from the
rhizome of the wild mandrake (Podophyllum peltatum). More specifically, it is a
glycoside of podophyllotoxin with a D-glucose derivative.]
FAMILY- Barberidaceae
CHEMICAL CONSTITUENT - Prenylated flavonoids, flavonoid glycoside, and
labdane diterpenes.
(5S,5aR,8aR,9R)-9-(4-Hydroxy-3,5-dimethoxyphenyl)-8-oxo-5,5a,6,8,8a,9-
hexahydrofuro [3',4',6,7] naphtho[2,3-d] [1,3] dioxol-5-yl 4,6-O-(2-thienylmethylene)-
β-D-glucopyranoside
• Extract 4gm powder Podophyllum peltatum root by stirring and heating with
100ml of ethanol for about 10 minutes.
• Cool and filter the mixture
• Re-extract the residue with further 100ml of ethanol
• Combine the extracts and evaporate to about 20ml
• Add the ethanolic solution into 100ml of water, and extract three times with
50ml
• Ethyl acetate.
• Combine the extract and evaporate to dryness
• Isolate the Podophyllotoxin by preparative TLC
• Crystallization at 0℃ for several days

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• The mechanism of action appears to be related to the inhibition of type II
topoisomerase activity since teniposide does not intercalate into DNA or bind
strongly to DNA.
• Teniposide binds to and inhibits DNA topoisomerase II.
• The cytotoxic effects of teniposide are related to the relative number of
double-stranded DNA breaks produced in cells, which are a reflection of the
stabilization of a topoisomerase II-DNA intermediate.
USE: -
Teniposide is used to treat
• Acute lymphocytic leukemia (ALL; a type of cancer of the white blood
cells) in children
• Hodgkin's lymphoma
• Generalized malignant lymphoma
• Reticulocyte sarcoma
• Acute leukemia
• Glioblastoma
• Ependymoma
• Astrocytoma
• Bladder cancer
• Neuroblastoma and other solid tumors
• Introducing the hydroxyl group at 2- and 4- positions of phenyl ring can
increase the selectivity and potency of the drug.
• Compounds without the hydroxyl groups are found to be less active.
• Introduction of hydroxyl groups at ortho and para groups at 2-phenyl ring
showed stronger topo II inhibitory activity
• Compounds having hydroxyl groups at meta position showed potent topo II
inhibitory activity and strong antiproliferative activity.

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• Overall, the hydroxyl groups at ortho and meta positions are important for the
activity of the drug.
• TENIPOSIDE INJECTION, SOLUTION 10 MG/1ML
• VUMON INJECTION, SOLUTION 10 MG/1ML
• VUMON LIQUID 10 MG
CARDIOVASCULAR DRUGS
LOVASTATIN
BOTANICAL SOURCE:
• A Fungal secondary metabolite.
• Introduced in to the market by Merck in 1987 for the treatment of
hypercholesterolemia.
• Lovastatin is a cholesterol-lowering drug produced by filamentous fungi
including Monascus ruber, Aspergillus terreus and Pleurotus ostreatus. It
inhibits the activity of (3S)-hydroxymethylglutaryl-coenzyme A (HMG-CoA)
reductase, which catalyzes the conversion of HMG-CoA to mevalonate, a key
step in cholesterol biosynthesis.
(3R,5R)-7-[(1S,2S,6R,8S,8aR)-2,6-dimethyl-8-[(2S)-2-methylbutanoyl] oxy-
1,2,6,7,8,8a-hexahydronaphthalen-1-yl]-3,5-dihydroxyheptanoic acid
ISOLATION OF LOVASTATIN
• Presently, lovastatin is derived from the fermentation broth which comprises of
the microorganism preferably a fungus belonging to the genus Aspergillus,
preferably Aspergillus terreus (ATCC 20542) or its hyperproducer thereof.

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• The process comprises lowering the pH of the fermented broth containing
lovastatin, present mostly in the form of mevinolinic acid to 2.0 to 3.0, and
incubating the broth for about 20–60 hours at a temperature from about 40–60°
C. affecting the lactonization of mevinolinic acid and recovering the
corresponding lovastatin from the solution thereof. The acid for lowering the pH
may be selected from the commonly used acids, preferably the mineral acids like
hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, etc.
• In a preferred method, the broth is incubated for 24 hours. In a further preferred
embodiment, the broth is incubated at a temperature in the range of 40–60° C.,
most preferable being 50–60° C.
• Lovastatin may also be isolated from the solution by extracting it with a solvent
followed by concentration of solvent, crystallization and drying the product.
Solvent which may be used is generally selected from esters such as ethyl acetate,
butyl acetate or aromatic hydrocarbons such as toluene.
Inhibition of 3-hydroxy-3-methyl glutaryl coenzyme A [HMGCoA] Reductase, a key
enzyme involved in the biosynthesis of cholesterol.

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USES: -
• Statins are the first-choice drug for primary hyperlipidaemias with raised LDL
and CH levels.
• They are the first-choice drugs for dyslipidaemia in diabetics.
• The 3,5 dihydroxycarboxylate is essential for inhibitory activity. compounds
containing a lactone are prodrugs requiring in vivo hydrolysis.
• The absolute stereochemistry of the 3-and 5-hydroxyl groups must be same as the
mevastatin and lovastatin.
• A double bond b/w C6 and C7 can either increase or decrease activity. The ethyl
group provides optimal activity for compounds containing ring A and some
heterocyclic rings (pyrrole ring of atorvastatin). The ethenyl group is optimal for
compounds with other rings such as indole and pyrimidine rings seen in
fluvastatin and cerivastatin.
Ring A subclass-
• The decalin ring is essential for anchoring the compound to the enzyme active
site. Replacement with a cyclohexane ring resulted in 10,000-fold decrease in
activity.
• Stereochemistry of the ester side chain is important for activity, the conversion
of this ester to an ether resulted in a decrease in activity.
• Methyl subtitution at the R2 position increases activity (simvastatin is more
potent than lovastatin).
• β hydroxyl group substitution at the R1 position enhances hydrophilicity and may
provide some cellular specificity.
Ring B subclass

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• The para- fluorophenyl cannot be coplanar with the central aromatic ring.
(structural restraints to cause coplanarity have resulted in a loss of activity).
• R substitution with aryl groups of hydrocarbon chains enhances lipophilicity
and inhibitory activity.
Brand or Generic
Form
Strength Dosage Form
Lovastatin Tablets 10 mg Tablet (Oral)
Mevacor 20 mg Tablet (Oral)
Altoprev 20 mg Tablets, extended-
release
Advicor 20 mg with Extended-release Niacin
500mg
Tablet (Oral)
Advicor 20 mg with Extended-release Niacin
750mg
Tablet (Oral)
Advicor 20 mg with Extended-release Niacin 1 g Tablet (Oral)
TEPROTIDE
BOTANICAL SOURCE: Teprotide is nonapeptide which has been isolated from
the snake Bothrops jararaca.

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(2S)-1-[(2S)-1-[(2S,3S)-2-[[(2S)-5-amino-2-[[(2S)-1-[(2S)-5-
(diaminomethylideneamino)-2-[[(2S)-1-[(2S)-3-(1H-indol-3-yl)-2-[[(2S)-5-
oxopyrrolidine-2-carbonyl] amino] propanoyl] pyrrolidine-2-carbonyl] amino]
pentanoyl] pyrrolidine-2-carbonyl] amino]-5-oxopentanoyl] amino]-3-
methylpentanoyl] pyrrolidine-2-carbonyl] pyrrolidine-2-carboxylic acid
ISOLATION: -
The antihypertensive effects of teprotide were first observed by Sergio Ferreira in
1965 and it was first isolated by Ferreira et al. along with eight other peptides in 1970.
Teprotide was synthesized in 1970 by Ondetti et al. and from there its antihypertensive
properties were studied more closely.
• Teprotide inhibits in a competitive manner the degradation of angiotensin I by
the converting enzyme.
• They exert their hemodynamic effect mainly by inhibiting the renin-angiotensin
system. They also modulate sympathetic nervous system activity and increase
prostaglandin synthesis. They cause mainly vasodilation and mild natriuresis
without affecting heart rate and contractility.
USES: -
Drugs used in the treatment of acute or chronic vascular HYPERTENSION regardless
of pharmacological mechanism. Among the antihypertensive agents are DIURETICS;
(especially DIURETICS, THIAZIDE).

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DICOUMAROL
BIOLOGICAL SOURCE –
• Isolated from Melilotus alba known as white melilot, a plant belongs to the family
Fabaceae,
• And also, Melilotus officinalis, known as yellow sweet clover, yellow melilot and
common melilot.
• Dicumarol is a coumarin-like compound found in sweet clover.
• It is now known to be present in many other plants. Dicoumarol derivative,
warfarin [3-(a-acetonylbenzyl)-4-hydroxycoumarin], is commonly used as a
natural anticoagulant for the prevention and treatment of excessive blood-clotting
disorder
• Dicoumarol (INN) or Dicumarol (USAN) is a naturally occurring anticoagulant
that functions as a functional vitamin K depleter (similar to warfarin, a drug that
dicoumarol inspired). It is also used in biochemical experiments as an inhibitor
of reductases.
FAMILY- Fabaceae
4-hydroxy-3-[(4-hydroxy-2-oxo-2H-chromen-3-yl) methyl]-2H-chromen-2-one
OR
3,3'-methanediylbis(4-hydroxy-2H-chromen-2-one)
ISOLATION: -
• Powdered plant aerial part (50g) was extracted by Soxhlet apparatus with ethanol
(80%, 250mL) till exhaustion.
• The extract was concentrated by evaporation under vacuum. Water (100g) was
added and the suspension was partitioned with petroleum ether (2x 100ml).

23
• The pet ether layer was discarded and the aqueous layer was extracted with ether
(3x100ml). The combined ether layers were dried with anhydrous sodium
sulphate, filtered and evaporated under vacuum.
• The residue purified by column chromatography (silica gel, DCM mobile phase).
The collected fractions were analysed by TLC comparing with standard
coumarin.
• Like all 4-hydroxycoumarin drugs it is a competitive inhibitor of vitamin K
epoxide reductase, an enzyme that recycles vitamin K, thus causing depletion of
active vitamin K in blood.
• This prevents the formation of the active form of prothrombin and several other
coagulant enzymes.
• These compounds are not antagonists of Vitamin K directly as they are in
pharmaceutical uses but rather promote depletion of
vitamin K in bodily tissues allowing vitamin K's
mechanism of action as a potent medication for
dicoumarol toxicity.
• The mechanism of action of Vitamin K along with the toxicity of dicoumarol are
measured with the prothrombin time (PT) blood test.
USES: -
• Anticoagulant
• Variety of pharmaceutical activities such as anti-inflammatory, antibacterial,
antiviral, anticancer, anti-HIV, and antiproliferative properties.
• Rodenticide
• Coumarin and its derivatives are principal oral anticoagulants
• Coumarin is water insoluble, however 4-hydroxy substitution confers weakly
acidic properties to the molecule that makes it water soluble under slightly
alkaline conditions.
• The followings are the structures of coumarin and its derivatives (Coumarin, 4-
Hydroxycoumarin, Warfarin and Dicoumarol)
• Warfarin is marketed as the sodium salt as racemate, however, The S (-) isomer
is about times more potent than the R (+) isomer
• The minimal requirements for anticoagulant activity are:
1. 4-hydroxy group

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2. a 3-substituent
3. a bis molecule.
• 3-Indanediones the 1,3-indanediones have been known to be anticoagulant since
1940s. A commercially available indandione is anisindione. The molecule has a
weakly ionizable proton on C-2 that is extracted in alkaline solutions to confer
mildly soluble properties.
• Warfarin Sodium (Tablet) 5mg
NEUROMASCULAR BLOCKING DRUGS
CURARE alkaloids
BIOLOGICAL SOURCE –
• Tubocurarine is a non-depolarizing neuromuscular blocking agent and the first
identified curare alkaloid. Dried extract from the bark and stems of Strychnos
species e.g., S. castelnaei, S. toxifera, S. crevauxii belongs to Family-
Loganiaceae and from Chondodendron species, Family- Menispermaceae.
• Curare contains several alkaloids (4-7%), the most important is d-tubocurarine
(quaternary amxmonium structure with two ether bridges).
(1S,16R)-9,21-dihydroxy-10,25-dimethoxy-15,15,30-trimethyl-7,23-dioxa-15,30-
diazaheptacyclo[22.6.2.2³,⁶.1⁸,¹².1¹⁸,²².0²⁷,³¹.0¹⁶,³⁴]hexatriaconta-
3,5,8(34),9,11,18(33),19,21,24,26,31,35-dodecaen-15-ium

25
ISOLATION: -
➢ Stage1: -Powdered material is moistened with water and mixed with alkali like
sodium & potassium carbonate, ammonia, lime. Make a paste with water, dry,
repowder.
Concept: -Lime (calcium hydroxide), combines with acid, tannins, and other
phenolic substances and sets free alkaloids.
➢ Stage2: - extract the free alkaloids by hot continuous percolation with chloroform
or any other organic solvents.
Concept: -the free alkaloids dissolve together with other substances soluble in
solvent.
➢ Stage3: - agitate the chloroform soln. With successive portion of dil. sulphuric
acid separating the aqueous layer before adding the next portion of acid.
Concept: -the alkaloids are converted into alkaloidal sulphates, which being
soluble in water, pass into aqueous layer.
➢ Stage4: - Make the mixed aqueous liquid alkaline with ammonia, collect the
precipitate that forms, wash with water and dry.
Concept: - Ammonia decomposes the alkaloidal sulphates forming ammonium
sulphates, soluble in water, and the free alkaloid which being practically insoluble
in water is precipitated.

26
D-tubocurarine is a long acting; competitive neuromuscular blocker competes with
acetylcholine for receptor sites at the motor end plate, thereby reducing the response of
the end plate to acetylcholine. This results the skeletal muscle relaxation. It also has
Histamine releasing and ganglionic blocking properties.
USES: -
• It is a non-depolarizing neuromuscular blocking agent, employed IM and IV as a
skeletal muscle relaxant to secure muscle relaxation in surgical procedures.
• It is used to control and reduce convulsions of strychnine poisoning and of
tetanus.
• It is used as a diagnostic aid in myasthenia gravis
• Use as spider bite treatment.
ANTI-MALARIAL DRUGS AND ANALOGUES
Artemisinin
BIOLOGICAL SOURCE – Artemisinin is a natural product that can be extracted
from the leaves of artemisia annua.
FAMILY- Asteraceae

27
COMMON NAME: -Sweet worm wood, sweet annie, sweet sagewort, annual
mugwort or annual wormwood
CHEMICAL CONSTITUENT: - Active constituent was identified as the
sesquiterpene endoperoxide artemisinin
Artemisinin, dihydro artemisisnin, artemisin, artemisic acid.
STRUCTURE & IUPAC NAME: -
(3R,5aS,6R,8aS,9R,12S,12aR)- octahydro-3,6,9-trimethyl-3,12- epoxy-12H-
pyrano[4,3-j]- 1,2-benzodioxepin-10(3H)-one

28
ESTIMATION: -
TLC METHOD-
Stationary Phase – Silica Gel G
Mobile Phase – Petroleum ether: ethyl acetate (1:2)

29
DETECTING AGENT-
1. Spray the plate with p-dimethyl amino benzaldehyde and heat at 80℃ to
produce color. The spot is quantified by densitometry at 600nm.
2. The use of 2% vanillin-H2SO4 acid produce color was measured at 560nm.
 Unique structure bearing endoperoxide lactone (1,2,4 – trioxane)
 High selectivity due to its interaction with haem which accumulates in parasitized
RBC’s as byproduct of haemoglobin lysis.
 Free haem is toxic to the parasite which is converted thereby to nontoxic
haemozoin.
 1,2,4 trioxanes form a complex with Fe (II) of haem & generate Oxyl radicals
which are toxic to the parasite.
OR
➢ Haemozoin is parasite pigment deposited within a food vacuole after digestion of
haemoglobin.
➢ The iron of the heme directly reduces the peroxide bond in artemisinin, generating
high-valent ironoxo species and resulting in a cascade of reactions that produce
reactive oxygen radicals (disrupts cellular redox cycle) which damages the
parasite and lead to its death.
USES: -
• Effective against malaria & cerebral malaria
• Hepatitis B
• Schistosomiasis (caused by schistosomes)
• Several blood parasitic protozoans
• Against a variety of cancer cell lines including breast cancer
• Human leukemia
• Colon
• Small-cell lung carcinomas
• Drug-resistant cancers

30
• Presence of a ‘Trioxane’ moiety which consists of the Endoperoxide & Doxepin
oxygens that are evidently displayed by a simplified version of 3-Aryl trioxanes.
• Reduction of Artemisinin to Dihydro artemisinin gives rise to a chiral centre, that
may ultimately lead to the formation of ‘Prodrugs’ which could either be oil
soluble or water soluble.
• Like the simpler Aryl trioxanes the two prevailing stereoisomers Artemether,
Artesunate which are found to be active.
• Only one isomer of Artemisinin prodrug exhibits predominance exclusively. The
alpha isomer predominates in forming the subsequent Hemi-succinate ester which
is water soluble. The beta isomer predominates in producing the subsequent
nonpolar methyl & ethyl ethers.
• 1,2,4 trioxane ring had a potency greater than Artemisinin itself but lacked
stability in vivo.
• Ether substituted drugs, Artemether & Arteether are oil soluble & can be
administered IM & converted to dihydro artemisinin in vivo.
Side effects:
• Vomiting
• Nausea
• Anorexia
• dizziness
• Mild blood abnormalities
Adverse effects:
• allergic reaction
• significant liver inflammation

31
QUININE
BIOLOGICAL SOURCE- Cinchona consists of dried bark of the cultivated trees
of Cinchona officinalis Linn, C. ledgeriana, C. calisaya and C. succirubra
FAMILY- Rubiaceae.
CHEMICAL CONSTITUENT- 25 Quinoline alkaloids, mainly Quinine,
Quinidine, Cinchonine, Cinchonidine.
(R)-[(2S,4S,5R)-5-ethenyl-1-azabicyclo [2.2.2] octan-2-yl] -(6-methoxyquinolin-4-yl)
methanol
ISOLATION-
• The bark is stripped and dried in the sun.
• This is crushed to a fine powder and then treated with lime and caustic soda
solution for several hours and finally extracted with hot petroleum.
• The solvent petroleum is drawn off and the petroleum extract is washed with
dilute sulphuric acid in a lead lined vessel provided with a powerful stirrer.
• The acid aqueous layer, while still hot, is neutralised and allowed to stand when
the neutral sulphates of the alkaloids (quinine, cinchonine and cinchonidine)
crystallise out.
• The mixtures of sulphates of three alkaloids are recrystallised when quinine
sulphate, having minimum solubility crystallises out first while the sulphates of
cinchonine and cinchonidine remain in the mother liquor.
• The crude quinine sulphate is redissolved in water, decolorised with charcoal and
recrystallised until cinchonidine and cinchonine are reduced to the required
percentage

32
• Quinine may be obtained from the sulphate by precipitation with alkali, washing
and drying.
USES: -
• Antimalarial
• skeletal muscle relaxant
• Night muscles spasm and
• abortifacient.

33
Quinine Dihydrochloride (QuinCare) Injection (ampule) 600mg/2mL
Quinine tablet Tablet 200mg
Quinine Sulphate Tablet Tablet 300mg

34
CHEMISTRY OF MACROLIDE ANTIBIOTICS
Erythromycin
BIOLOGICAL SOURCE: - Erythromycin is a bacteriostatic antibiotic drug
produced by a strain of Saccharopolyspora erythraea (formerly Streptomyces
erythraeus) and belongs to Pseudonocaridaceae.
FAMILY- Macrolide group of Antibiotic
(3R,4S,5S,6R,7R,9R,11R,12R,13S,14R)-6-[(2S,3R,4S,6R)-4-(dimethylamino)-3-
hydroxy-6-methyloxan-2-yl]oxy-14-ethyl-7,12,13-trihydroxy-4-[(2R,4R,5S,6S)-5-
hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy-3,5,7,9,11,13-hexamethyl-
oxacyclotetradecane-2,10-dione
Soil sample was collected. 1 g soil was suspended in 9 ml of sterile double distilled
water. Diluted aliquots (0.1 ml) of 10−2, 10−3, 10−4 and 10−5) were spread on the
isolation plates containing starch casein agar, oatmeal agar and actinomycetes isolation
agar containing combination of penicillin and chloramphenicol. Plates were incubated
at 28 ◦c for 7–14 days. Stock culture of isolated strain was preserved in 15% glycerol
(v/v) at 4 ◦c.

35
• Erythromycin displays a bacteriocidal activity particularly at higher
concentrations.
• It prevents the growth of bacteria by inhibiting their protein synthesis.
• Erythromycin binds to the 23s rRNA molecule in the 50S ribosomal subunit.
• This binding blocks thee exit of the growing peptide thus inhibiting the
translocation of the peptides.
OR
Erythromycin acts by inhibition of protein synthesis by binding to the 23S ribosomal
RNA molecule in the 50S subunit of ribosomes in susceptible bacterial organisms. It
stops bacterial protein synthesis by inhibiting the transpeptidation/translocation step of
protein synthesis and by inhibiting the assembly of the 50S ribosomal subunit. This
results in the control of various bacterial infections. The strong affinity of macrolides,
including erythromycin, for bacterial ribosomes, supports their broad‐spectrum
antibacterial activities.
USES: - Erythromycin is used for treatment of,
• Acne Vulgaris
• Acute Otitis Media caused by
Haemophilus Influenzae
• Acute pelvic inflammatory
disease caused by Neisseria
Gonorrheae Infection
• Bacterial Infections
• Chancroid
• Chlamydia Trachomatis
• Chlamydial ophthalmia
neonatorum
• Community Acquired Pneumonia
(CAP)
• Diphtheria
• Erythrasma
• Gastroparesis
• Granuloma Inguinale
• Intestinal amebiasis caused by
entamoeba histolytica
• Legionella Pneumophila
Infections
• Listeria infection
• Lower Respiratory Tract
Infection (LRTI)
• Lymphogranuloma Venereum
• Nongonococcal urethritis
• Ophthalmia neonatorum
(gonococcal)
• Pertussis
• Postoperative Infections
• Primary Syphilis
• Respiratory Tract Infections
(RTI)
• Staphylococcal Skin Infections
• Syphilis
• Upper Respiratory Tract Infection
• Urea plasma urethritis
• Whooping Cough

36
• Inflammatory papular lesions
• Predominant skin comedones,
papules and pustules
• Prophylaxis of Rheumatic fever
• Pustular lesions
• Skin and skin-structure infections
• Skin and subcutaneous tissue
bacterial infections caused by
streptococcus pyogenes
• Superficial ocular infections
Generic name Brand name Dosage Dose
Erythromycin Erythrocin Drops 100mg/2mL
Erythromycin Erythrocin IV 1 g
Erythromycin Erythrocin Tablets 250,500,1 g
Erythromycin Erythrocin Lotion 2 p wbv
Erythromycin Akne-mycin Ointment 20mg/1g
Erythromycin Erythromycin ophthalmic Ointment Ointment 5mg/1g

37
Azithromycin
BIOLOGICAL SOURCE: - Azithromycin is an azalide, derived from
erythromycin, and a member of a subclass of macrolide antibiotics with bactericidal and
bacteriostatic activities.
FAMILY- Macrolide group of antibiotics.
(2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-[(2S,3R,4S,6R)-4-(dimethylamino)-3-
hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy-3,5,6,8,10,12,14-heptamethyl-1-oxa-
6-azacyclopentadecan-15-one
MECHANISM OF ACTION: -
Azithromycin reversibly binds to the 50S ribosomal subunit of the 70S ribosome of
sensitive microorganisms, thereby inhibiting the translocation step of protein synthesis,
wherein a newly synthesized peptidyl tRNA molecule moves from the acceptor site on
the ribosome to the peptidyl (donor) site, and consequently inhibiting RNA-dependent
protein synthesis leading to cell growth inhibition and cell death. The strong affinity of
macrolides, including azithromycin, for bacterial ribosomes, is consistent with their
broad‐spectrum antibacterial activities.
USES: -
• Respiratory tract infections
• Skin infections (SSTIs)
• STIs (Chlamydia, GC, chancroid)

38
• Traveler's diarrhea
• Mycobacterium avium complex (MAC)
• Acute Bacterial Sinusitis (ABS)
• Acute Otitis Media
• Acute bacterial exacerbation of COPD caused by Haemophilus Influenza
Infections, Moraxella Catarrhalis Infection, Streptococcus Pneumoniae
Infections
• Bacterial Conjunctivitis
• Bacterial Sinusitis
• Cervicitis
• Community Acquired Pneumonia (CAP)
• Pelvic Inflammatory Disease (PID)
Brand Name/ generic name Dosage Dose
AZASITE Ophthalmic Solution 10 mg/1mL
AZITAL Tablet 500mg
AZISURE Oral suspension 200mg/5mL
AZITHROMYCIN (AZCIN) Tablets 250mg
ZITHROMAX Powder (IV Infusion only) 100mg/mL (500mg)
AZIWELL Injection (IM & IV) 500mg
Roxithromycin
BIOLOGICAL SOURCE: - Roxithromycin is a semi-synthetic derivative of the
macrolide antibiotic erythromycin that includes an N-oxime side chain on the lactone
ring, with antibacterial and anti-malarial activities.
FAMILY- Macrolide group of Antibiotic.

39
(3R,4S,5S,6R,7R,9R,11S,12R,13S,14R)-6-[(2S,3R,4S,6R)-4-(dimethylamino)-3-
hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy-10-(2-methoxyethoxymethoxyimino)-
3,5,7,9,11,13-hexamethyl-oxacyclotetradecan-2-one
Roxithromycin prevents bacterial growth by interfering with their protein synthesis. It
binds to the 50S subunit of bacterial ribosomes and inhibits the translocation of peptides.
USES: - Roxithromycin is used for treatment of
• Respiratory tract
• Urinary and soft tissue infections
• Acute pharyngitis (sore throat and discomfort when swallowing)
• Tonsillitis
• Sinusitis
• Acute bronchitis (infection of the bronchi causing coughing)
• Pneumonia (lung infection characterised by fever, malaise, headache)
• Skin and soft tissue infections
• Non gonococcal urethritis
• Impetigo (bacterial infection causing sores on the skin).

40
Brand Name/ generic name Dosage Dose
ROXYWELL Suspension 30mL
ACTIROX Tablet 150mg
ROXCIN Tablet 150mg
Clarithromycin
BIOLOGICAL SOURCE: -
Clarithromycin, a semisynthetic macrolide antibiotic derived from erythromycin.
FAMILY- Macrolide group of ntibiotic.
(3R,4S,5S,6R,7R,9R,11R,12R,13S,14R)-6-[(2S,3R,4S,6R)-4-(dimethylamino)-3-
hydroxy-6-methyloxan-2-yl]oxy-14-ethyl-12,13-dihydroxy-4-[(2R,4R,5S,6S)-5-
hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy-7-methoxy-3,5,7,9,11,13-hexamethyl-
oxacyclotetradecane-2,10-dione

41
Clarithromycin is first metabolized to 14-OH clarithromycin, which is active and works
synergistically with its parent compound. Like other macrolides, it then penetrates
bacteria cell wall and reversibly binds to domain V of the 23S ribosomal RNA of the
50S subunit of the bacterial ribosome, blocking translocation of aminoacyl transfer-
RNA and polypeptide synthesis. Clarithromycin also inhibits the hepatic microsomal
CYP3A4 isoenzyme and P-glycoprotein, an energy-dependent drug efflux pump.
USES: - Clarithromycin is used for treatment of,
• Acute Bacterial Exacerbation of Chronic Bronchitis (ABECB)
• Acute maxillary sinusitis
• Bacterial Infections
• Bartonellosis
• Community Acquired Pneumonia (CAP)
• Duodenal ulcer caused by helicobacter pylori
• Infective Endocarditis
• Lyme Disease
• Mycobacterial Infections
• Otitis Media (OM)
• Pertussis
• Streptococcal Pharyngitis
• Streptococcal tonsillitis
• Uncomplicated skin and subcutaneous tissue bacterial infections

42
Brand/Generic name Dosage Dose
Biaxin Tablet film coated, extended release 500mg
Biaxin granules Oral suspension 250mg/5mL
Monoclar dry syrup Powder for oral suspension 125mg/5mL
BETA LACTUM ANTIBIOTICS
Cephalosporins
BIOLOGICAL SOURCE: - The cephalosporins are a class of β-lactam
antibiotics originally derived from the fungus cephalosporium acremonium
FAMILY: The fungus belongs to family Hypocreaceae
(2R)-2-[(R)-[[(6R)-6-amino-6-carboxyhexanoyl]amino]-carboxymethyl]-5-
methylidene-2H-1,3-thiazine-4-carboxylic acid

43
Cephalosporins are bactericidal and have the same mode of action as other β-lactam
antibiotics (such as penicillins), but are less susceptible to β-lactamases. Cephalosporins
disrupt the enzyme transpeptidase there by inhibiting synthesis of the peptidoglycan
layer forming the bacterial cell wall.
OR
Cephalosporin
Act as transpeptidase enzyme
Inhibit transpeptidation reaction
Block peptidoglycine synthesis
Activation of Autolytic enzyme
Increase the permeability of cell membrane
Cell explodes and lysed
Death of microorganism
USES: -
• UTI
• Infection of gut
• Respiratory tract infection
• Boils, abscess
• Prophylaxis in surgery
• Biliary sepsis
• Person allergic to penicillin
• Meningitis
• Gonorrhoea
• Infected burns
• Septicaemia
• Aspirin Pneumonia
• Mixed infection
• Tonsillitis

44

45
• Cefotiam - For treatment of severe infections caused by susceptible bacteria.
• Cefmenoxime - Used to treat female gynaecologic and obstetric infections
caused by susceptible aerobic (including the gonococcus) and anaerobic bacteria.
• Cefmetazole - For the treatment of infections caused by susceptible organisms.
• Ceftazidime - An injected broad-spectrum beta-lactam antibiotic used to treat or
prevent a variety of bacterial infections, including pneumonia, gynaecological
infections, bone and joint infections, and septicemia, among others.
• Cefalotin - A broad-spectrum cephalosporin antibiotic used for the treatment of
serious bacterial infections in various locations, such as the urinary tract, skin,
bone, and lower respiratory tract.
• Cefotaxime - A third generation cephalosporin used to treat susceptible Gram
negative and Gram-positive bacterial infections.
• Cephalexin - A first generation cephalosporin used to treat certain susceptible
bacterial infections.
• Cefixime - A third generation cephalosporin used to treat susceptible Gram
negative and Gram-positive bacterial infections.
• Cephaloglycin - For treatment of severe infections caused by susceptible
bacteria.

46
• Cefaclor - A second generation cephalosporin used to treat a wide variety of
infections in the body.
• Ceforanide - For the treatment of infections caused by susceptible organisms.
• Cefuroxime - A cephalosporin indicated for the treatment of a variety of
infections including acute bacterial otitis media, several upper respiratory tract
infections, skin infections, urinary tract infections, gonorrhea, early Lyme
disease, and impetigo.
Carbapenem
BIOLOGICAL SOURCE: Carbapenem antibiotics were originally developed at
Merck & Co. from the carbapenem thienamycin, a naturally derived product of
Streptomyces cattleya.
FAMILY: Streptomyces cattleya belongs to family Streptomycetacea
(5R)-1-azabicyclo [3.2.0] hept-2-en-7-one
carbapenems are bactericidal beta-lactam antibiotics that bind to penicillin-binding
proteins (PBPs). By binding and inactivating these proteins, carbapenems inhibit the
synthesis of the bacterial cell wall by inhibiting the enzyme transpeptidase, which leads
to cell death.
FORMULATION PRODUCTS AND USES: -
• Imipenem - A carbapenem antibiotic normally administered with cilastatin to
treat a variety of infections.

47
• Meropenem - A carbapenem antibiotic used to treat a wide variety of infections
in the body.
• Biapenem - Biapenem has been used in trials studying the treatment of Bacterial
Infections.
• Ertapenem - A carbapenem antibiotic used for the treatment of moderate to
severe bacterial infections caused by specific sensitive organisms.
• Doripenem - An antibiotic of the penem class used to treat complicated intra-
abdominal and urinary tract infections.

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