IC50

Ethyl Butyrate (EB) are common ester components for Nitrocellulose (NC) lacquer thinner. They exhibit good solubility for NC lacquer, but they are flammable and explosive and could also bring negative effect on environment. In this paper, their dissolution rates, lower explosive limits (LELs) and the half maximal inhibitory concentrations (IC 50) (on Dunaliella bardawil) were studied. Their dissolution rates for NC lacquer are about 39.64, 32.81, 23.56, 19.76, 26.50 and 19.36 mg/min, respectively. Their LELs are about 3.145%, 2.060%, 1.845%, 1.540%, 1.740% and 1.425%, respectively. And their IC 50 are about 20.47, 11.35, 3.18, 1.00, 3.37 and 1.98 g/L, respectively. Considering from the three aspects, MA is a better ester component for NC lacquer thinner than other five esters, while BA and EB are relative worse components for NC lacquer thinner.

Introduction: The superoxide radical (O 2-), hydroxyl radical (OH) are generated in physiochemical pathways. All biological systems have innate antioxidant defence mechanisms but these mechanisms can be inefficient due to poor diet intake, pollution, stress and chemicals etc. Therefore, it is imperative to consume antioxidants to shield cells from destruction by free radicals. Shilajatu is such a drugs of prime importance that has been advocated in the management of various ailments ranging from Diabetes to Immunomodulation and Antioxidant. Materials and Methods: The antioxidant potential of Shuddha Shilajatu along with impact of geography and processing media on it, was determined by using DPPH i.e. 1,1-diphenyl-2-picrylhydrazyl Free Radical Scavenging Assay. Test was performed at the wavelength of 517 nm using 1 cm optical path cuvette at room temperature. The ultraviolet spectrum of Shuddha Shilajatu and Ascorbic acid was performed by UV-Vis spectrophotometer at different concentrations. The experiment was carried out in triplicate. The result was compared with ascorbic acid as it was taken as standard control under the same conditions. The sample concentration at which initial absorbance of DPPH solution get lowered by 50% has been considered as the endpoint for evaluating the antioxidant potential. Results: It has been found that Shilajatu samples processed in Triphala kwatha have shown better antioxidant profile than water processed samples. Moreover, sample procured from Amritsar showed much better antioxidant activity in comparison to Shilajatu sample procured from Nepal. Conclusion: Processing media and geography significantly modulate the effect and activities of Shilajatu.