Extractive separation of lower valent vanadium by complexation with picolinic acid

Summary Vanadium (III), obtained by sodium dithionite reduction of vanadium (V), forms a coloured complex with picolinic acid which is extracted into chloroform from slightly acidic medium. The method is free from interference by relatively high concentrations of analytical important elements such as iron, cobalt, nickel, zinc, copper, titanium, aluminium, chromium, molybdenum, tungsten and uranium. The proposed method of separation is simple and rapid and its applicability has been tested by the satisfactory recovery of vanadium from a variety of synthetic and natural samples.     

Fibrinolytic activity of kaempferol isolated from the fruits of Lagenaria siceraria (Molina) Standley

This study was undertaken to isolate a flavonol, kaempferol, from the fruits of Lagenaria siceraria (bottle gourd) as a sole compound and to explore the fibrinolytic potential of the methanolic extract of the fruits of L. siceraria and the isolated compound using their in vitro activity. The fibrinolytic activity in terms of percentage of plasma clot liquefaction was determined by plasma clot lysis at 37°C in 24?h. The fibrinolytic activity of both substances was compared to the well-known thrombolytic agent streptokinase (30,000?IU). The percentage of fibrinolytic activity of the extract and isolated compound were found to be 54.72?±?0.7210 and 77.37?±?1.3010, respectively. Streptokinase was considered as the standard fibrinolytic enzyme for comparative purposes and had 91.46?±?0.7625% fibrinolytic activity. The conclusion drawn in our study after testing the hypothesis by experimental procedures is that in vitro fibrinolytic activity on plasma clots is an inherent property of kaempferol isolated from the fruits of L. siceraria, and its comparison with streptokinase is a new aspect for further study.     

A New Isolate from Fusarium proliferatum (AUF-2) for Efficient Nitrilase Production

A fungal isolate from Fusarium proliferatum strain AUF-2 has been found to have a high nitrilase activity (≥1,000 U/l culture). The present work describes optimization of growth conditions and production medium to achieve maximum nitrilase production. The most effective carbon and nitrogen sources for nitrilase production were glucose and sodium nitrate, respectively. ε-Caprolactam was found to be the best inducer for maximum nitrilase production with 80 g/l wet cell biomass and 26 U/g nitrilase activity. An overall nitrilase activity of ≥2,000 U/l culture was obtained in this study, which is one of the best activities reported so far in any Fusarium strain. Chemo-profiling has shown that the strain is versatile in its ability to hydrolyze both aliphatic as well as aromatic nitriles. Efforts are being made to use the strain for biotransformation of pharmaceutical substrates.     

Studies on complexes of 4-(2-thiazolyl)thiosemicarbazide with some bivalent metal ions

Summary The 4-(2-thiazolyl)thiosemicarbazide HTTSC, reacts with metal ions to yield two types of complex M(HTTSC)₂ Cl₂ [M=cobalt(II), nickel(II) copper(II), cadmium(II), or mercury(II)] and [M(TTSC)₂] [M=cobalt(II), nickel(II) or copper(II)]. These complexes have been characterized by elemental analyses and studied by magnetic and spectroscopic techniques. Tetrahedral coordination around cadmium(II) and mercury(II), square planar geometry around cobalt(II) and nickel(II) in [Co(TTSC)₂] and [Ni(HTTSC)₂]Cl₂, respectively, and octahedral stereochemistry for the remaining complexes is proposed.