Материалы II студенческой межфакультетсткой конференции первокурсников по биоорганической химии
CEPHALOSPORIN Pooja Magendra, group 30. Scientific adviser is Levashova Olga
жүктеу/скачать 3.18 Mb.
|
- Бұл бет үшін навигация:
- DENTISTRY DEPARTMENT
- Pyrazolone
CEPHALOSPORINPooja Magendra, group 30. Scientific adviser is Levashova Olga.Cephalosporins discovery credited to brotzu in 1945 in sewer water off coast of saridina. Several compounds isolated from mold acremonium chrysogenum with cephalosporin C as basic nucleus for future drugs. First introduced into clinical use in 1994 (cephalosporin). Divided into “generations” for convenience many drugs in same “generation” not chemically related and differnent spectrum of activity. Currently for generation of cephalosporins but which generation a particular drug belongs often a matter of debate. Generalization that with increasing “generation” activity in vitro against gram positive organisms decreases while activity against gram negatives increases(but an oversimplification). Cephalosporins one of the most widely used Drug classes in the US and worldwide . Mechanism of resistance to cephalosporins may confer resistance to other beta-lactam agents. Ranking of 4 generation cephalosporins as highly important and 3 generation agents as critically important in guidancene 152 ; both critically important in W.H.O criteria . Ranking of antimicrobiasis according to importance in human medicine one factor to consider in overall risk management strategy for use of drugs in animals according to guidance 152. DENTISTRY DEPARTMENTPorphyrinAbdulrhman Hamidan, group 3. Scientific adviser is Tishakova Tatyana.Porphyrins are a group of organic compounds, many naturally occurring. One of the best-known porphyrins is heme, the pigment in red blood cells; heme is a cofactor of the protein hemoglobin. Porphyrins are heterocyclic macrocycles composed of four modified pyrrole subunits interconnected at their α carbon atoms via methine bridges (=CH−). Porphyrins are aromatic. Synthesis: The committed step for porphyrin biosynthesis is the formation of δ-aminolevulinic acid (δ-ALA, 5-ALA or dALA) by the reaction of the amino acid glycine with succinyl-CoA from the citric acid cycle. Two molecules of dALA combine to give porphobilinogen (PBG), which contains a pyrrole ring. Four PBGs are then combined through deamination into hydroxymethyl bilane (HMB), which is hydrolysed to form the circular tetrapyrroleuroporphyrinogen III. This molecule undergoes a number of further modifications. Intermediates are used in different species to form particular substances, but, in humans, the main end-product protoporphyrin IX is combined with iron to form heme. Bile pigments are the breakdown products of heme. Porphyrins have been evaluated in the context of photodynamic therapy since they strongly absorb light, which is then converted to energy and heat in the illuminated areas. This has been applied in macular degeneration using verteporfin. PyrazoloneAyman olleik, group 3. Scientific adviser is Tishakova Tatyana.Pyrazolone, a five-membered-ring lactam, is a derivative of pyrazole that has an additional keto (=O) group. It has a molecular formula of C3H4N2O. There are two possible isomers: 3-pyrazolone and 5-pyrazolone. Among the screened samples, 5c and 6c have showed excellent antibacterial activity at 1.6125 µg/mL concentration against S. aureus bacteria as compared to the standard drug Ceftriaxone which is active at 3.125 µg/mL concentration. They also showed similar activity as that of standard, against B. subtilis, E. coli and P. aeruginosa , at 1.6125 µg/mL concentration. Pyrazolone drug hypersensitivity (PDH) may manifest as angioedema, urticaria, and/or life threatening anaphylactic shock. Although it has been suggested that PDH is an immunologic, probably IgE-mediated reaction, the diagnosis of PDH is still based on clinical history because there is no reliable in vitro diagnostic method currently used in clinical practice. Pyrazolone derivatives, which include dipyrone, antipyrine, aminopyrine and propyphenazone, are widely used analgesics. Dipyrone, the most widely used pyrazolone, has been the most studied. The pyrazolidine derivatives, phenylbutazone and oxyphenbutazone, which are not generally used for analgesia since they differ from the pyrazolones in terms of efficacy and tolerance. Dipyrone is an inhibitor of cyclo-oxygenase but, unlike aspirin, its effect is rapidly reversible. The inhibition of prostaglandin biosynthesis contributes to the analgesic activity of the pyrazolone derivatives. Peak plasma concentrations of the pyrazolone derivatives generally occur 1 to 1.5 hours after oral administration. Half-lives vary from 1 to 2 hours with propyphenazone, to about 7 hours with dipyrone (2 hours for the active metabolite of dipyrone, 4-methylaminoantipyrine, MAA). Half-life of antipyrine varies considerably between individuals (5 to 35 hours). Unlike the NSAIDs generally, the pyrazolone derivatives antipyrine, aminopyrine and propyphenazone are minimally bound to plasma proteins. The pyrazolones undergo extensive biotransformation, aminopyrine and dipyrone being converted to active metabolites. Dipyrone is the only drug for which results of recent double-blind trials are available. Oral dipyrone has been shown to be more effective than an equal dose of aspirin or paracetamol in alleviating postoperative pain, and intravenous dipyrone 2.5g was similar in efficacy to pethidine 50 mg. In patients with acute ureteral or biliary colic, dipyrone 2.5g intravenously was similar in efficacy to indomethacin 50 mg or pethidine 50 mg. The most frequently reported side effects of the pyrazolone derivatives are skin rashes. Gastrointestinal side effects are rare. Blood dyscrasias, mostly associated with aminopyrine, have received wide attention in the medical literature, but their true incidence with dipyrone is considerably lower than the often quoted incidence for amidopyrine reported more than 30 years ago. жүктеу/скачать 3.18 Mb. Достарыңызбен бөлісу:
|