Synthesis and antituberculostic activity of some novel 1,3,4-oxadiazole

A series of 5-[3'-oxo-6'-[substituted aryl]-2',3',4',5'-tetrahydropyridazin-2'-yl methyl]-2-substituted 1,3,4-oxadiazole has been synthesized. Appropriate aromatic hydrocarbon reacts with succinic anhydride in presence of AlCl[3] to yield beta-Aroyl propionic acid [1a]. The corresponding acid is cyclised with hydrazine hydrate to give 6-[substituted aryl]-2,3,4,5-tetrahydro3-pyridazinone [1b]. This intermediate after reaction with ethyl bromo acetate, hydrazinolysed into 3-oxo-6-[substituted aryl]-2,3,4,5-tetrahydropyridazinyl acetohydrazide [1c]. The resulting product was converted into 5-[3'oxo-6'-[substituted aryl]-2',3',4',5'-tetrahydropyridazin-2'-yl methyl]-2-substituted 1,3,4-oxadiazole [Scheme-I]. All the final compounds have been structurally elucidates on the basis of IR, [1]H-NMR, mass spectral data and elemental analysis and screened for antitubercular activity

profile of natural sweetener - stevia

The small perennial shrub, Stevia rebaudiana Bertoni is native to valley of Rio Monday in Paraguay. It is one of 150 species of genus Stevia which contains diterpene glycosides e.g. Stevioside, Rebaudioside A, B, C [Dulcoside B], D, E, F, [Dulcoside A], Steviolmonoside, Steviolbioside and Rubusoside in its leaves. All these are responsible for making Stevia about 300 times sweeter than sucrose [0.4% solution]. Stevioside and Rebaudioside A are the abundant glycosides in this plant responsible for the potent sweet taste of the drug. Extract of Stevia leaves have been used for many years as sweetening agent in traditional treatment of diabetes in South America. Several studies demonstrated that Stevia significantly decreases glucose level and increases glucose tolerance in diabetic type II volunteers and experimental animals. Stevioside and Rebaudioside A exert hypoglycemic, insulinotropic [enhance insulin release] and glucogonostatic activities. Organoleptic evaluation of Stevia for sweetener properties demonstrated that it exerts intensively sweet taste superior to most of other sweeteners. Other pharmacological activities such as antihypertensive, anticancer, non-carcinogenic, gastroprotective, antibacterial etc. have been demonstrated by several studies. The present literature survey reveals the phytochemical and pharmacological activities of the Stevia rebaudiana Bertoni