Free radical-scavenging and antimutagenic potential of acetone, chloroform and methanol extracts of fruits of Argemone mexicana

The antioxidant potency of acetone, chloroform and methanol extracts of Argemone mexicana was investigated by employing in vitro systems like nitroblue tetrazolium (NBT) and 1,1-Diphenyl-2- picrylhydrazyl (DPPH) free radical scavenging assay whereas antimutagenic activity was determinedby Maron and Ames assay using Salmonella typhimurium TA100 tester strain against sodium azide. In this study, dried fruits of A. mexicana were extracted with different solvents by maceration method in order of increasing polarity. It was observed that, acetone extracts were comparatively more effective than the other extracts in both the assays. The maximum inhibitory activities noticed were 79.0 and 71.0% in NBT and DPPH assay, respectively, at the maximum concentration tested. The inhibitory potential was compared with standard antioxidant (L-ascorbic acid). The IC50 value of the acetone extract of the fruit of A. mexicana was more than that of L-ascorbic acid showing the maximum inhibitory effect. Among the different extracts, the antimutagenic effect of methanol extract was found to be more followed by acetone and chloroform extracts. The methanol extract showed maximum inhibition of 80.5% at doses of 1.00~1033 μg/ml in pre-incubation modes of the experiments, respectively. Chloroform extract showed maximum inhibition of 62.14 and 50.71% in co-incubation and pre-incubation mode of experiments at the highest concentration tested. Antimutagenicity of the acetone extract was more in co-incubation than pre-incubation mode of theexperimentation. These results indicate that, A. mexicana fruit extracts have antioxidant as well as antimutagenic properties. The antioxidant and antimutagenic activities were significantly correlated.Key words: Argemone mexicana, antioxidant, antimutagenic, sodium azide

Biogenesis of nanoparticles: A review

Advancement in nanotechnology mainly depends upon advancement in nanomaterial. There are many chemical routes known to use toxic chemicals for synthesis of nanoparticles but the need of the hour is to use environmental benign, greener and safer routes. Researchers are looking to use various living organisms as ‘nanoparticle factories’. Various biological entities like bacteria, fungi, diatoms, higher plants, actinomycetes and viruses have been used for this purpose. Due to their normal biosynthetic pathways, they can reduce salt into corresponding nanoparticles. This review includes some of the biological sources which have been used by researchers for the synthesis of nanoparticles and their applications.Keywords: Biogenesis, nanofactories, nanoparticles, antimicrobial activity, semiconductor nanoparticles.African Journal of Biotechnology Vol 13(28) 2778-278

Production of ethanol from tuberous plant (sweet potato) using Saccharomyces cerevisiae MTCC-170

The aim of this work was to research a bioprocess for bioethanol production at laboratory scale from raw sweet potato using Saccharomyces cerevisiae MTCC-170. In order to obtain maximum conversion of starch into fermentable sugar, optimum parameters for the liquefaction were determined as 104 to 105°C, 0.15% v/w of α-amylase enzyme solution (300 U/ml) and 30 g dry-weight sweet potato mash/100 ml distilled water, respectively with a 74.38% loss in dry weight during the process. For saccharification process, the optimum dose of amyloglucosidase was 0.25% v/w (300 U/ml) with 16.82% glucose production at pH 5.0 and temperature 60°C after 1 h. The fermentation parameters like inoculum size, temperature, pH and different concentrations of nutrients were also determined. The maximum ethanol concentration, that is, 7.95% (v/v) was obtained with 10% inoculum size at pH 6.0 after 48 h. Furthermore, out of the three nitrogen sources (yeast extract, peptone and ammonium sulphate) tested for ethanol production, peptone at a concentration of 1.5 g/L was found to be best (7.93%). From the present study, it may be concluded that sweet potato can be an attractive feedstock for bioethanol production from both the economic stand points and environment friendly.Keywords:  Sweet potato starch, ethanol, liquefaction, saccharification, Saccharomyces cerevisiae MTCC-170African Journal of Biotechnology, Vol 13(28) 2874-288