The most common mode of action for antibiotics is the inhibition of cell wall synthesis. Antibiotics that inhibit cell wall synthesis work because of the fact that most eubacteria have peptidoglycan-based cell walls but mammals do not. Growth is prevented by inhibiting peptidoglycan synthesis. Thus these antibiotics only work for actively growing bacteria. The cell wall of new bacteria that grew in the presence of cell-wall-synthesis inhibitors is deprived of peptidoglycan. These bacteria will be subjected to osmotic lysis.In addition, gram-negative bacteria generally are less susceptible to inhibitors of cell wall synthesis than are gram-positive bacteria. In the former cell wall synthesis inhibitors fail to reach the cell wall because they are blocked by the gram-negative outer membrane.Penicillin is the classic example of an inhibitor of cell wall synthesis. Other examples include: ampicillin, bacitracin, carbapenems, cephalosporin, methicillin, oxacillin and vancomycin
The most common mode of action for antibiotics is the inhibition of cell wall synthesis. Antibiotics that inhibit cell wall synthesis work because of the fact that most eubacteria have peptidoglycan-based cell walls but mammals do not. Growth is prevented by inhibiting peptidoglycan synthesis. Thus these antibiotics only work for actively growing bacteria. The cell wall of new bacteria that grew in the presence of cell-wall-synthesis inhibitors is deprived of peptidoglycan. These bacteria will be subjected to osmotic lysis.In addition, gram-negative bacteria generally are less susceptible to inhibitors of cell wall synthesis than are gram-positive bacteria. In the former cell wall synthesis inhibitors fail to reach the cell wall because they are blocked by the gram-negative outer membrane.Penicillin is the classic example of an inhibitor of cell wall synthesis. Other examples include: ampicillin, bacitracin, carbapenems, cephalosporin, methicillin, oxacillin and vancomycin
This presentation provides a comprehensive introduction to antibiotics, exploring their historical significance, classifications, and essential role in modern medicine. Attendees will gain a profound understanding of the diverse mechanisms through which antibiotics act to combat bacterial infections.
Outline:
Introduction to Antibiotics
Definition and historical context
Significance in treating bacterial infections
Classification of Antibiotics
Broad-spectrum vs. narrow-spectrum antibiotics
Classes: penicillins, cephalosporins, tetracyclines, etc.
Mechanisms of Antibiotic Action
Inhibition of cell wall synthesis (e.g., penicillins)
Disruption of protein synthesis (e.g., macrolides)
Inhibition of nucleic acid synthesis (e.g., quinolones)
Interference with metabolic pathways (e.g., sulfonamides)
Selective Toxicity
Understanding the concept and importance
How antibiotics target bacterial structures without harming human cells
Resistance to Antibiotics
Factors contributing to antibiotic resistance
Consequences and global impact
Case Studies
Examples of well-known antibiotics and their mode of action
Real-world applications and success stories
Future Trends and Challenges
Emerging technologies in antibiotic development
Strategies to address antibiotic resistance
Conclusion
Recap of key points
Emphasis on the critical role antibiotics play in public health
This presentation aims to provide a solid foundation for understanding antibiotics and their mode of action, catering to both beginners and those looking to deepen their knowledge in the field. Through engaging visuals and clear explanations, you will have a heightened awareness of the vital role antibiotics play in preserving human health while being mindful of the challenges posed by antibiotic resistance.
A protein synthesis inhibitor is a substance that stops or slows the growth or proliferation of cells by disrupting the processes that lead directly to the generation of new proteins. All of the antibiotics that target bacterial protein synthesis do so by interacting with the bacterial ribosome and inhibiting its function. The ribosome might not seem like a very good target for selective toxicity, because all cells, including our own, use ribosomes for protein synthesis.The good thing is that bacteria and eukaryotes have ribosomes that are structurally different. Bacteria have so-called 70S ribosomes and eukaryotes have 80S ribosomes. No, not '70s and '80s ribosomes, although that would be pretty entertaining. The S stands for 'Svedberg unit,' and it refers to the rate at which particles sediment down into the tube during high-speed ultracentrifugation. Basically, it tells us about the ribosome's molecular weight and shape.
70S and 80S ribosomes are different enough that antibiotics can specifically target one and not the other. Let's take a closer look at the bacterial 70S ribosome and see where some different kinds of antibiotics act on it. Remember that ribosomes are made of RNA and protein and that they have two subunits, one large and one small.
The bacterial 70S ribosome's subunits are the 50S subunit and the 30S subunit. Yes, I know, 50 + 30 = 80, not 70, but this is not a math mistake. Using the Svedberg unit to measure ribosomes means that things don't always add up perfectly, because rates of sedimentation are not additive like molecular weights are.
Before we get into the specifics of how antibiotics inhibit bacterial ribosomes, let's briefly review how ribosomes work. First, a tRNA loaded with a particular amino acid enters the ribosome at the A site. The tRNA's anticodon has to match the codon, or group of three nucleotides on the mRNA. Then, at the P site of the ribosome, a peptide bond forms between the previous amino acid and the new amino acid. Finally, the empty tRNA exits at the E site. This process repeats for the whole length of the mRNA, and the polypeptide chain continues to grow.
002. Cephalosporins for students 2023 Prof. P. Ravisankar.pdfDr. Ravi Sankar
Cephalosporins, Why Cephalosporins? Advantages of cephalosporins over penicillin, Mechanism of action of cephalosporins, Classification of cephalosporins, Structures of some important cephalosporins and cephamycins, Oximinocephalosporins, SAR of cephalosporins,Hydrolytic reactions, degradation and stability of cephalosporins, Uses of cephalosporins, Comparison between 6-APA and 7-ACA and penam and cepham.
1a. Prof. P. Ravisankar, Vignan Pharmacy College, Vadlamudi, Guntur, AP., Ind...Dr. Ravi Sankar
Antibiotics, characteristics of an antibiotic, Brief historical background of antibiotics, Modern History of antibiotics, Classification of antibiotics, four groups of beta-lactam antibiotics, Classification of Penicillins, Penicillinase resistant Penicillins, Narrow spectrum anti-staphylococcal Penicillins, Amino Penicillins, Nomenclature of Penicillins, Stereochemistry of Penicillins, Hydrolysis of Penicillins, SAR of Penicillins, Mechanism of Penicillins, Beta-lactamase inhibitors, Therapeutic uses of Penicillins, Penicillin advantages, and disadvantages, Hypersensitivity or allergic reactions of Penicillins.
Tetracyclines are Octahydro napthacene derivatives which are bacteriostatic potent broad spectrum antibiotics and are the most widely prescribed form of antibiotic after penicillins.
TETRA means = four
CYCL means = hydrocarbon rings
INE means = derivation.
Tetracyclines are introduced 50 years ago as potent broad spectrum antibiotics.
They are biosynthesized form acetic acid and propionic acid units in microorganisms.
Finally, one of the best ways of reducing cancer is …..
Cancer prevention is an essential component of all cancer control plans because about 40 % of cancers are preventable.
Firstly…Public education campaigns are important in highlighting the dangers of smoking because possibly as many as 22 % (in the UK 30%) of cancers are caused by smoking.
Secondly, another 30% of cancers are diet-related. Decades of research have clearly shown that by living a healthy life, people can reduce the risk of developing the disease.
Screening tests help in finding Cancer earlier before developing any symptoms.
The benefits of eating high-fiber foods, fruit, and vegetables.
Epigallocatechin gallate, an antioxidant present in green tea, is another potential protective agent.
Finally, The new research funded by the UK and USA which aims to show the number of cancer cases could be prevented by known lifestyle and environmental factors,
like being a non-smoker, keeping a healthy weight, drinking less alcohol, eating a healthy balanced diet, and avoiding being exposed to certain infections or radiation.
Every country, regardless of resource level, can take steps to curb the cancer epidemic, save lives and prevent unnecessary suffering.
Finally, cancer prevention efforts should be preceded by a systematic planning process on cancer control.
Antibiotics definition, Early and modern history, classification of antibiotics, Mechanism of antibacterial action, bacterial cell and drug targets, penicillins nomenclature, degradation reactions of penicillins, medical classification of penicillins, SAR of penicillins, Mechanism of penicillins, Betalactamase inhibitors, Therapeutic uses of penicillins, toxicity of penicillins, Side effects of penicillins.
NOVEL SEPARATION AND QUANTITATIVE DETERMINATION OF LEVOFLOXACIN, PRULIFLOXACI...Dr. Ravi Sankar
The core AIM of the present study is to develop a novel, rapid, precise and accurate RP-HPLC method for simultaneous separation and quantification of six fluoroquinolones OF LEVOFLOXACIN (LEVO), PRULIFLOXACIN (PRFX), GATIFLOXACIN (GATI), SPARFLOXACIN (SPAR), MOXIFLOXAXIN (MOXI) AND BALOFLOXACIN (BALO) for the the day to day analysis.
The author felt that a novel single method for separation and quantification of all the above said drugs on single chromatographic system without any minor changes in detection wavelength and mobile phase composition.
To develop rapid, sensitive and economical analytical method based on HPLC for separation and estimation of six fluoroquinolones pharmaceutical dosage forms.
To develop method with shorter run time and better sensitivity.
Reducing the solvent consumption to make it more eco-friendly.
Avoid the column damage by minimizing the buffer strength and pH of mobile phase than reported methods.
To validate the method for different parameters like Accuracy, Precision, Linearity, specificity, Robustness International Conference on Harmonization ICH Q2(R1) guidelines..
To apply the developed RP-HPLC method in the analysis of pharmaceutical formulations.
Analytical method development and validation of novel Levofloxacin, Pruliflox...Dr. Ravi Sankar
For the first time simple, selective, sensitive RP-HPLC method was developed for the separation and quantitative development of LEVO, PRFX, GATI, SPAR, MOXI and BALO relating to fluoroquinolone anti bacterials in pharmaceutical dosage forms. The most important advantage of developed method was that the 6 separate drugs can be determined on a single chromatographic system without modifications in detection wavelength and mobile phase by RP-HPLC. The chromatographic separation of the selected drugs was carried out on Welchrom C18 column consisting of 250 mm X 4.6 mm, 5 µm particle size utilizing mixture of 10 mM phosphate buffer (pH 3.1): Acetonitrile in the ratio of 70:30,v/v as mobile phase at the flow rate of 1mL/min with detection wave length at 293 nm by using UV spectrophotometric detector with total run time of 10 minutes and 3.613, 4.230, 4.707, 5.497, 5.880 and 6.253 minutes of retention time obtained for LEVO, PRFX, GATI, SPAR, MOXI and BALO respectively. All calibration curves for six drugs showed indicated linearity over a concentration range of 2-10 µg/mL. The results regarding to limit of detection (LOD) and limit of quantitation (LOQ) for LEVO, PRFX, GATI, SPAR, MOXI and BALO were found to be 0.116 µg/mL and 0.348 µg/mL; 0.152 µg/mL and 0.460 µg/mL; 0.084 µg/mL and 0.255 µg/mL; 0.186 µg/mL and 0.558 µg/mL, 0.162 and 0.493, 0.112 and 0.390 respectively. These results clearly show low values of LOD and LOQ. The said developed method was ultimately utilized for quantification of marketed formulation.
NOVEL SIMULTANEOUS SEPARATION AND QUANTITATIVE DETERMINATION OF FOUR SARTANS...Dr. Ravi Sankar
The core AIM of the present study is to develop a novel, rapid, precise and accurate RP-HPLC method for simultaneous separation and quantification of Hydrochlorothiazide along with four sartans Telmisartan(TELM), Losartan(LOSA), Olmesartan(OLME) and Valsartan(VALS).
To develop Novel methods for separation and quantification of all the above said drugs on single chromatographic system without any minor changes in detection wavelength and mobile phase composition.
Total quality management (TQM), and current Good Manufacturing Practice (cGMP...Dr. Ravi Sankar
TQM, cGMP, Introduction, Definition, Importance, TQM frame work, Key concepts (Principles) of TQM, specific steps in the cycle, Benefits of TQM, cGMP, principles of GMP, Improtance of GMP, why GMP established?, difference between GMP and cGMP, GMP and cGMP regulations, code of federal regulations.
Tetracyclines BY Dr. P. Ravisankar M. Pharm., Ph.D.Dr. Ravi Sankar
Tetracyclines by Dr. P. Ravisankar M. Pharm., Ph.D.
Definition
Introduction
Classification
Historical background
Sources
Chemistry
SAR of tetracyclines
Mechanism of action of tetracyclines
Spectrum of activity
Uses of tetracyclines
Side effects of tetracyclines
Dr. P. Ravisankar M. Pharm., Ph.D.
Vitamin A
Vitamin D
Vitamin E
Vitamin K
Definition
Introduction
Classification
Structures,Functions,Deficiency,Diseases,Toxicity and uses.
Introduction to diuretics.
Therapeutic approaches.
Normal physiology of urine formation.
Classification of drugs .
Mechanism of action of Acetazolamide.
Mechanism of action of Thiazides.
Mechanism of action of Loop diuretics.
Mechanism of action of potassium sparing diuretics &aldosterone antagonists.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
1. MECHANISMS OF ANTIBACTERIAL
ACTIONDr. Panchumarthy ravisankar, Professor and HOD
Vignan Pharmacy College, Vadlamudi, Guntur, Andhra Pradesh, India.
INHIBITION OF BACTERIAL CELL WALL SYNTHESIS
Inhibition of bacterial cell wall synthesis leads to bacterial cell lysis and death. Agents operating in this way include penicillins, Cephalosporins
and Vancomycin. As animal cells do not have a cell wall, they are unaffected by such agents.
INHIBITION OF FOLIC ACID MEETABOLISM
Antibacterial agents act on five main targets-cell metabolism, the cell wall, the plasma membrane, protein synthesis,and nucleic acid function.
The principle of chemotherapy or the magic bullet involves the design of chemicals that show selective toxicity against bacterial cells rather
than mammalian cells.
Sulfonamides are similar in structure to para-aminobenzoic acid—a component of dihydropteroate. As a result, they can bind to the bacterial
enzyme responsible for dihydropteroate synthesis and act as an inhibitor.
Mammals synthesize tetrahydrofolate from folic acid acquired from the diet. They lack the enzyme targeted by sulfonamides. Bacteria lack
the transport mechanisms required to transport folic acid into the cell.
Trimethoprim inhibits dihydrofolate reductase—an enzyme that converts folic acid to tetrahydrofolate. It has been used in combination with
sulfamethoxazole in a strategy known as sequential blocking.
Aminoglycosides, tetracyclines, chloramphenicol, strepto-gramins, lincosamides, and macrolides inhibit protein synthesis by binding to the
bacterial ribosomes involved in the translation process.
INTERACTIONS WITH THE PLASMA MEMBRANE
Interactions with the plasma membrane: some antibacterial agents interact with the plasma membrane of bacterial cells to affect membrane
permeability. This has fatal results for the cell. Polymyxins and tyrothricin operate in this way. The peptides Valinomycin and Gramicidin
both acts on ion-conducting antibiotics (Ionophores) act on the plasma membrane and allow the uncontrolled movement of ions across the cell
membrane leading to cell death.
DISRUPTION OF PROTEIN SYNTHESIS
Disruption of protein synthesis means that essential proteins and enzymes required for the cells survival can no longer be made. Agents that
disrupt protein synthesis include the Rifamycins, Aminoglycosides, Tetracyclines, and Chloramphenicol.
INHIBITION OF NUCLEIC ACID TRANSCRIPTION AND REPLICATION
Inhibition of nucleic acid transcription and replication prevents cell division and/or the synthesis of essential proteins. Agents acting in this
way include nalidixic acid , Ciprofloxacin, Norfloxacin, Balofloxacin, Ofloxacin, Enrofloxacin, Moxifloxacin, Gatifloxacin,
Gemifloxacin, Travafloxaacin.
VIGNAN PHARMACY COLLEGE, VADLAMUDI, GUNTUR.
References
Graham L.Patrick, An introduction to Medicianl Chemistry, Oxford Universirty press Inc., New York, 2006.