1. The document discusses various terpenoids found in plants including iridoids, naphthoquinones, and modified terpenoids. It provides details on the extraction, chemical constituents, and uses of specific terpenoids like gentian, artemisia, taxus. 2. Gentian root contains the bitter iridoid glycoside gentiopicrin which is used as a tonic and for digestive issues. Artemisia contains the antimalarial sesquiterpene lactone artemisinin. Taxus bark contains the anticancer diterpenoids paclitaxel and docetaxel. 3. The document provides information to help identify and understand these important

1. DEPARTMENT
OF
PHARMACOGNOSY
SUB – PHYTOCHEMISTRY AND
PHARMACOGNOSY II
UNITII
IRIDOIDS AND NAPHTHAQUINONES
Prepared by : Snehal Uttam Kashid (Asso. professor)
Department of Pharmacognosy, SPMs college of
pharmacy, akluj

2. TERPENOIDS
 Terpenes constitute one of the most important groups of essential
oils.
 The isoprenoids, sometimes called terpenoids, are a large and
diverse class of naturally-occurring organic chemicals similar to
terpenes.
 Derived from five-carbon isoprene units assembled and modified in
thousands of ways.
 Terpenes may be classified by the number of terpene units in the
molecule; a prefix in the name indicates the number of terpene units
needed to assemble the molecule.

3. TERPENOIDS

4. Iridoids
 Iridoids are a type of monoterpenoids in the general form of cyclo-
pentanopyran, found in a wide variety of plants and some animals.
 They are biosynthetically derived from 8-oxogeranial.
 Iridoids are typically found in plants as glycosides, most often
bound to glucose.
 It is also known as iridane skeleton (cis-2-oxa-bicyclo-[4,3,0]-
nonane )
 It include Secoiridoids by cleavage of the 7,8 bond of the
cyclopentane ring.
 This group contain about 500 known structures which comprises
a) More than 300 iridoid glycoside
b) More than 100 secoiridoids glycoside
c) Near about 100 non- glycosidic compound

5. Extraction
 Delicate due to their great instability
 Instability darkening that takes place soon after plant
collection in many species containing iridoids
 Extraction with polar solvent alcohols of various concentration
 Initial separation, re-dissolving the extraction residue in water,
then re-extracting this with immiscible solvents of increasing
polarity
 Fractionation: chromatography on alumina on charcoal (with
risk of irreversible adsorption), on porous polymers (e.g.
XAD- 2) with polar eluents & more and more by polar reverse
phase HPLC
 Purification TLC, HPLC
 Detection Trim and Hill color reagent: Dilute solution of
CuSO4 and HCl, blue color
 Detection spray: vanillin H2SO4, Hot HCl

6. Examples of iridoids
Iridoids
1. Gentian (bitter glycoside)
2. Picrorrhiza (bitter glycoside)
Modified Terpenoids
1.Quassia (bitter, triterpenoid lactone)
2. Tinospora (sesquiterpene glucoside)
3. Artemisia (sesquiterpenoid)
4. Taxus (diterpenoid)
5. Andrographis

7. Gentian root

8. 1. Gentian (bitter glycoside)
 Synonyms: yellow gentian root, gentiana, radix gentianae, gentian
root, gall weed, bitter ward.
 Biological Source: dried fermented roots and rhizomes of
Gentiana lutea
 Family: Gentianaceae.
 Geographical Source: Mountainous regions of Central and south
Europe, Turkey, Yugoslavia. Now: France, Italy, Germany.

9. Macroscopy of gentian
 Color :- Brownish
 Shape :- Sub-cylindrical , entire or longitudinally split pieces of
rhizomes and roots.
 Size :- 15-20 cm or more in length and 2.5-8 cm in thickness at
crown.
 Odour :- Characteristic odour
 Taste: is sweet at first and then intensely bitter afterwards
 The drug is brittle and breaks with a short fracture.

10. Cultivation and collection:
 Cultivation:
G. lutea requires a moist soil , good drainage and a suitable soil
consisting of loam , peat and grit.
Seeds are slow to germination ,seedlings frequently taking several
years to appear.
 Collection:
The plant is large perennial herb.
The drug is collected from 2-5 years old plant in autumn (Sept-
Dec).
Turf is stripped and the rhizomes are dug up.
It is cut into pieces of different length and dried quickly first in air
and then in sheds.
The drug becomes much dark in colour , looses some of its
bitterness and acquires a very distinctive odour.

11. Chemical constituents of
Gentian
 It contain bitter glycoside, alkaloids, yellow colouring matter, sugars,
pectin and fixed oil.
 Gentian consists the bitter glycoside Gentiopicrin (~2%) as a
principle active constituent which is water soluble. Having 12000
bitterness value.
 Yellow colour of gentian is due to xanthones & gentisin (
gentiamarin)
 On hydrolysis , it yields the aglycone gentiogenin and glucose.
 Gentiopicrin is a secoiridoid , gentiopicroside , and it is decomposed
on fermentation and drying of the drug.
 Other bitter compounds are Genticin , Amaropanin, Amarogentin
and Amaoswerin.
 Gentian also contains Gentin , Gentisic acid 0.03% (2,5 -
dihydoxybenzoic acid), Tannins , Pectin's and calcium oxalates.
 Gentian should yield 33-40% of water soluble extractive but highly
fermented root yields much less.

12. Chemical constituents

13. Chemical tests
1. Alcoholic extract when made alkaline. Shows blue or green
fluorescence.
2. Take moistened dry powder of gentian in test tube.
Cover test tube with filter paper soaked in dil .NaOH.
Keep test tube in water bath.
After sometimes expose filter paper to UV light.
It shows yellowish -green fluorescence.

14. Uses of gentian
 bitter tonic
 Stimulate gastric secretions
 GIT problems like indigestion
 Appetite enhancer
 Fever
 Hypertention
 Muscle spasm
 Parasitic worms
 Cancer
 Maleria
 wound healing

15. Adulterants
Adulterations occur due to careless collection.
1) The rhizomes of Rumex alphinus give the test for anthraquinone
derivatives.
2) Veratrum album .
3) Gentiana purpurea
4) Gentiana pannanica

17. Artemisia (sesquiterene)
 Synonyms : Sweet worm wood,sweet annie, sweet
sagewort, annual mugwort or annual wormwood
 Biological source: Leaves and the closed, unexpanded
flower heads of Artemisia annua, Artemisia bravifolia,
Artemisia cina, A.maritima and other species of
artimisia
 Family : Compositae

18. Macroscopy
 Geoghraphical source- native of china wildly cultivated
in pakistan, india west tibet,and turkey. In india
cultivated in kashmir punjab hariyana UP.
 Colour -flowers are yellow, other parts are whitish gray.
 Odour – aromatic, sweet
 Taste – bitter,camphor like
 Shape- flowers are ovel shape

19. Artemisia
 Active constituents:
 It is sesquiterene lactone with prominant antimalerial
activity.
 Contain volatile oil(1-2%) and crystalline substance
santonin & artimisin.
 Artemisinin, dihydro artemisisnin, artemisic acid.
 Other constituents are cineol, pinene and resin,

20. Artemisia
 Chemical test
Powdered drug 1gm boil it with alcohol
filter it add sodium hydroxide to the filtrate
warm it until red colour appears.

21. Uses
 Artemisinin and its derivatives have been used for the
treatment of malaria
 Parasitic worm (helminth) infections.
 Having strong anthelmintic action against round worm
 No or less effect against hook worm and tape worm.
Adultrants:
 Artimisia vulgaris

23. Taxus (Tricyclic diterpenoids)
 Synonyms: Yew Himalayan yew, pacific yew
 Biological Source: dried bark of Taxus baccata
(Europe) Taxus brevifolia & T. canadensis (North
america) Taxus cuspidata (Japan) Taxus wallichiana
(Himalaya).
 Family: Taxaceae.
 Geographical source: india (Himalaya), america,
canada
 It required high altitude 2000 to 3500meters.

24. Morphology

25. Morphology
 They are relatively slow-growing and can be very long-
lived,
 Plant height - 2.5–20 metres (8.2–65.6 ft),
 trunk girth - averaging 5 metres (16 ft).
 colour - reddish bark, dark-green leaves
 Shape - lanceolate, flat.

26. Culivation and collection
 The plant need to be mature( about I00 years) to be
large enough for exploitation of its bark.
 At this age the tree will be some 6-9 m high, and have a
trunk of about 25 cm in diameter.
 It requires the bark from about three mature 100-year-
old trees to provide one gram of taxol.
 And a course of treatment may needs 2 gms of taxol.

27. Chemical Constituents
 Tricyclic diterpenoids like:
Taxane skeleton, Taxusines, Taxagifen, Baccatin III,
Taxine, Taxol, Cephalomannine, Taxicine.
 Taxol derivatives like paclitaxol, docetaxol
 Other constituents are - polysacchrides, sterols,
proanthocynidines, bisflavonoids, fatty acids, lignans
and cynogenetic glycosides.
Paclitaxo

28. MOA of Taxanes
These drugs act by interfering with mitotic spindle
They prevent micotubule disassembly into tubulin
monomers
shows anti cancer action.

29. Uses of Paclitaxel
 Paclitaxel: mitotic spindle poison
 MOA: it promotes assembly of tubulin dimers into
microtubules which is stabilized by inhibiting their
depolymerization
 uses - Advanced ovarian cancer, metastatic breast
cancer
 Side effect of Paclitaxel - neutropenia, peripheral
neuropathy, CVS, alopecia
 dose: 135-175 mg/m2

30. Uses of Docetaxel
Docetaxel: mitotic spindle poison
 MOA: it promotes assembly of tubulin dimers into
microtubules which is stabilized by inhibiting their
depolymerization Uses - breast cancer
 Side effect: severe neutropenia, hypersensitivity
reaction, water retention, cutaneous reaction.
 Dose : 100 mg/m2

31. Uses
 Ovarian cancer
 Lung carcinoma
 Gastric & Cervical cancers
 Prostate & colon cancer

32. How it is given
 Taxol is given as an injection or infusion into the vein
(intravenous, IV).
 There is no pill form of Taxol.
 Taxol is an irritant that can cause inflammation of the
vein through which it is given.
 Because severe allergic reactions have occurred in
some people taking Taxol, patient will be asked to take
medications to prevent allergic reaction.

33. Bibliography
 Kokate, C.K., Purohit, A.P. and Gohkale, S.B.
(2019) Pharmacognosy. In Terpenoids, 57th Edition,
Nirali Prakashan, Pune.
 Pharmacognosy And Phytochemistry By Vinod Rangari.
2009 2nd edition, Career Publications.