Bioactive metabolites from the leaves of Withania adpressa

Bioactive metabolites from marine invertebrates

Recent results in the chemistry of bioactive marine products are presented. Concerning the cytotoxic a-carbolines : grossularins A and B, the mechanism of the toxicity using supercoiled DNA and synthesis of the imidazolo-a-carboline moiety are presented. In the polysulfur compounds series, the structure of lissoclinotoxin B is proposed as well as a new synthesis of pentathiepins. Novel sesquite...

the effect of traffic density on the accident externality from driving the case study of tehran

در این پژوهش به بررسی اثر افزایش ترافیک بر روی تعداد تصادفات پرداخته شده است. به این منظور 30 تقاطع در شهر تهران بطور تصادفی انتخاب گردید و تعداد تصادفات ماهیانه در این تقاطعات در طول سالهای 89-90 از سازمان کنترل ترافیک شهر تهران استخراج گردید و با استفاده از مدل داده های تابلویی و نرم افزار eviews مدل خطی و درجه دوم تخمین زده شد و در نهایت این نتیجه حاصل شد که تقاطعات پر ترافیک تر تعداد تصادفا...

Bioactive metabolites from Spilanthes acmella Murr.

Spilanthes acmella Murr. (Compositae) has been used as a traditional medicine for toothache, rheumatism and fever. Its extracts had been shown to exhibit vasorelaxant and antioxidant activities. Herein, its antimicrobial, antioxidant and cytotoxic activities were evaluated. Agar dilution method assays against 27 strains of microorganisms were performed. Results showed that fractions from the ch...

Bioactive secondary metabolites from Juncaceae species

Bioactive secondary metabolites from Salix tetrasperma Roxb.

Column chromatography of the light petroleum fraction from the methanolic extract of the stem bark of Salix tetrasperma Roxb. (Salicaceae) resulted in the isolation of beta-sitosterol acetate, friedelin, 3beta-friedelinol, beta-amyrin, beta-sitosterol, beta-sitosterol-O-glucoside in addition to palmitic acid. From the dichloromethane fraction of the leaves, catechol and tremulacin were isolated...