Synthesis, characterization and anti-inflammatory activity of some 1, 3,4 -oxadiazole derivatives

A series of five-membered heterocyclic rings were synthesized by the reaction between benzoyl chloride and various chlolro-nitro-benzoyl chlorides and semi carbazide to form [C[1]-C[7]] compounds and was tested for their anti-inflammatory activity determined by rat-paw-oedema method. All the synthesis compounds have been characterized by [1]HNMR, IR and Mass spectral data. The compounds were purified by column chromatography. All synthesized derivatives were determined by the carrageenan-induced rat-paw-oedema model for anti-inflammatory activity. The entire compound gives good response for the anti-inflammatory activity: [3-Chloro-N-[5-[3-Chloro-phenyl]-[1,3,4] oxadiazole-2yl] benzamide [C[4]], and [4-Nitro-N-[5-[4-Nitro-phenyl]-[1,3,4] oxadiazole-2yl] benzamide [C[7]]. For this activity, indometacin was used as a standard drug and compared to new synthesized drugs. Some new synthesized drugs have shown better activities for the anti-inflammation

Synthesis, characterization and biological screening of N-substituted derivatives of 5-benzyl-1,3,4-oxadiazole-2yl-2''-sulfanyl acetamide

A series of new N-substituted derivatives of 5-benzyl-1, 3, 4-oxadiazole-2yl-2''-sulfanyl acetamide [6a-n] were synthesized in three phases. The first phase involved the sequentially converting phenyl acetic acid into ester, hydrazide and finally cyclized in the presence of CS[2] to afford 5-benzyl-1, 3, 4-oxadiazole-2-thiol. In the second phase N-substituted-2-bromoacetamides were prepared by reacting substituted amines with bromoacetyl bromide in basic media. In the third phase, 5-benzyl-1,3,4-oxadiazole-2-thiol was stirred with N-substituted-2-bromoacetamides in the presence of N,N-dimethyl formamide [DMF] and sodium hydride [NaH] to get the target compounds. Spectral techniques were used to confirm the structures of synthesized compounds. Synthesized compounds were screened against butyrylcho linesterase [BChE], acetylcholinesterase [AChE], and lipoxygenase enzymes [LOX] and were found to be relatively more active against acetylcholinesterase

Inhibition of Hypoxic Pulmonary Vasoconstriction of Rats by Carbon Monoxide

Hypoxic pulmonary vasoconstriction (HPV), a unique response of pulmonary circulation, is critical to prevent hypoxemia under local hypoventilation. Hypoxic inhibition of K+ channel is known as an important O2-sensing mechanism in HPV. Carbon monoxide (CO) is suggested as a positive regulator of Ca2+-activated K+ channel (BK(Ca)), a stimulator of guanylate cyclase, and an O2-mimetic agent in heme moiety-dependent O2 sensing mechanisms. Here we compared the effects of CO on the HPV (Po2, 3%) in isolated pulmonary artery (HPV(PA)) and in blood-perfused/ventilated lungs (HPV(lung)) of rats. A pretreatment with CO (3%) abolished the HPV(PA) in a reversible manner. The inhibition of HPV(PA) was completely reversed by 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ), a guanylate cyclase inhibitor. In contrast, the HPV(lung) was only partly decreased by CO. Moreover, the partial inhibition of HPV(lung) by CO was affected neither by the pretreatment with ODQ nor by NO synthase inhibitor (L-NAME). The CO-induced inhibitions of HPV(PA) and HPV(lung) were commonly unaffected by tetraethylammonium (TEA, 2 mM), a blocker of BK(Ca). As a whole, CO inhibits HPV(PA) via activating guanylate cyclase. The inconsistent effects of ODQ on HPV(PA) and HPV(lung) suggest that ODQ may lose its sGC inhibitory action when applied to the blood-containing perfusate.