Deciphering the Antimicrobial Potential of Taxus wallichiana Zucc: Identification and Characterization Using Bioassay-Guided Fractionation.

Taxus wallichiana Zucc. is a high valued medicinal plant and has been mainly studied for its anti-cancer properties. However, research on its other important biological activities, such as its antimicrobial potential, still needs attention. The focus of the present study is to investigate the antimicrobial activity of secondary metabolites of T. wallichiana needles against 3 different groups of microorganisms, i. e., bacteria, actinobacteria, and fungi. Bioactive compounds from T. wallichiana needles were separated through column chromatography, and, TLC-bioautography. Mobile phases were optimized using Snyder's selectivity triangle. Antimicrobial spots were fractionated and compounds were identified by gas chromatography-mass spectroscopy (GC/MS) and liquid chromatography-mass spectrometry (LC/MS). Functional groups were characterized using Fourier transform infrared spectrometry (FTIR) and nuclear magnetic resonance (NMR) was used to identify the molecular structures. GC/MS and LC/MS data analysis confirm the presence of fatty acids (arachidic acid, behenic acid, palmitic acid, and stearic acid), vitamins (nicotinamide), and alkaloids (cinchonine, timolol), aminobenzamides (procainamide), carbocyclic sugar (myoinositol), and alkane hydrocarbon (hexadecane), having antimicrobial activity in the needles of T. wallichiana. To the best of our knowledge, this is the first report on the isolation and characterization of antimicrobial compounds from the needles of Taxus wallichiana (Himalayan yew). The data obtained from the present study will be supportive to the new drug discoveries in modern medicine with various combinations of medicinal plant's active constituents that can be used for curing many diseases.

Biodegradation of bisphenol A using psychrotolerant bacterial strain Pseudomonas palleroniana GBPI_508.

A psychrotolerant bacterial strain of Pseudomonas sp. (P. palleroniana GBPI_508), isolated from the Indian Himalayan region, is studied for analyzing its potential for degrading bisphenol A (BPA). Response surface methodology using Box-Behnken design was used to statistically optimize the environmental factors during BPA degradation and the maximum degradation (97%) was obtained at optimum conditions of mineral salt media pH 9, experimental temperature 25 °C, an inoculum volume of 10% (v/v), and agitation speed 130 rpm at the BPA concentration 270 mg L-1. The Monod model was used for understanding bacterial degradation kinetics, and 37.5 mg-1 half saturation coefficient (KS) and 0.989 regression coefficient (R2) were obtained. Besides, the utmost specific growth rate µmax was witnessed as 0.080 h-1 with the GBPI_508 during BPA degradation. Metabolic intermediates detected in this study by GC-MS were identified as valeric acid, propionic acid, diglycolic acid, and phenol. The psychrotolerant bacterial strain of Pseudomonas sp. (P. palleroniana GBPI_508), isolated from the Indian Himalayan region has shown good potential for remediation of BPA at variable conditions.

Comparative nutritional and antimicrobial analysis of Himalayan black and yellow soybean and their okara.

BACKGROUND: Soybean is believed to have good nutraceutical potential which is important for human health. Yellow soybean (YS) is generally used for the production of soymilk and other products, while black soybean (BS) is less explored. During the production of soymilk, residue, called okara is generated which is reported to have a good amount of nutrient content. Studies are generally performed with YS while BS is less explored. The present work is a comparison of the nutraceutical potential of BS and YS and their okara, mainly in terms of proximate, minerals, antinutrients, and isoflavone content and bioactivity of all types of samples in terms of antioxidant and antimicrobial activity. RESULTS: Compared to raw soybean, protein content decreased significantly in both types of okara. Phytochemicals like ascorbic acid, catechin, quercetin, and gallic acid were significantly (P < 0.05) high in BS residue in comparison to respective raw soybean. Among isoflavones, daidzin and genistin were found significantly varying among all the samples, and glycitin and glycitein were not present in YS. CONCLUSION: The nutraceutical potential and antimicrobial activity were comparative for both the raw beans and their okara, while the phytochemical contents and antioxidant activity were higher in the case of BS and its okara. © 2022 Society of Chemical Industry.

Microbial Degradation of Caffeine Using Himalayan Psychrotolerant Pseudomonas sp.GBPI_Hb5 (MCC 3295).

Caffeine, a xenobiotic compound, is continuously released into the environment. Fifteen psychrotolerant bacterial strains, isolated from the Indian Himalayan region, were screened for their caffeine degradation capacity. The medium for the growth of bacteria was optimized using Box-Behnken method. Among these bacteria, Pseudomonassp. (GBPI_Hb5), showing the best response, was further used for caffeine degradation in batch mode. The culture medium, having caffeine as a sole source of carbon, was used for analyzing the effect of pH, agitation speed, temperature, inoculum volume, and caffeine concentration on bacterial growth and its caffeine degradation potential. The bacterium GBPI_Hb5 showed approx. 93% caffeine degradation up to 96 h under controlled conditions. The compounds produced during the degradation of caffeine were also studied. The study is likely to have implications in the bioremediation of caffeine from polluted environments.

Thin layer drying behavior of Ginkgo biloba L. leaves with respect to Ginkgolide A and Bilobalide content and microbial load.

Influence of drying temperature (30-50 °C) and relative humidity (RH: 30-80%) on moisture content, energy requirement and quality of Ginkgo biloba leaves with respect to chemical markers namely Ginkgolide A (GA) and Bilobalide (BB), and microbial load of dried materials has been analyzed. Leaves were dried in climate control chamber with varying temperature and relative humidity (RH). Total time required for attaining equilibrium was higher for low temperature at all the RH levels as well as for high RH at all the temperatures. Energy requirement was found to increase at high RH and low temperature. GA and BB concentration increased during drying in comparison to that in fresh material. Microbial load analyzed for dried samples was also found within the limit as prescribed in European Pharmacopeia under the category 3B. 40 °C temperature and 50 % RH with less drying duration was observed as suitable conditions for better recovery of BB and GA content, less microbial load and less energy consumption, during drying of G. biloba leaves.

Antioxidant, antimicrobial activity and bioactive compounds of Bergenia ciliata Sternb.: A valuable medicinal herb of Sikkim Himalaya.

Bergenia ciliata Sternb., commonly known as Paashaanbhed, is a well known herb of Sikkim Himalaya with various pharmaceutical properties. However, scientific exploration of B. ciliata, growing in the Sikkim Himalaya, for phytochemicals and pharmacological properties is in infancy. With this view, the present study was undertaken to investigate B. ciliata leaf extracts for antioxidant, antimicrobial activity and bioactive compounds. Three solvents viz., methanol, ethyl acetate and hexane were used for extraction and the respective leaf extracts were analyzed for total phenolic and flavonoid contents along with the antioxidant and antimicrobial activities. Amongst the tested solvents, methanol was found to be the best solvent for extraction with highest total phenolic contents and the lowest IC50 values for the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. Methanol extract also exhibited effective antimicrobial activity, particularly against bacteria and actinomycetes. Further, high performance liquid chromatography (HPLC) analysis revealed that methanolic extract contains the highest amount of all the three analyzed bioactive compounds viz. bergenin, catechin and gallic acid. The current study suggests that the methanol extract of B. ciliata is a potential source of natural antioxidant and antimicrobial compounds that can be used in food and drug industries.

Antimicrobial and antioxidant phytochemicals in leaf extracts of Bergenia ligulata: a Himalayan herb of medicinal value.

Phenolic and flavonoid contents in leaf extracts of Bergenia ligulata have been analysed for their contribution in antimicrobial and antioxidant activities. The extracts were prepared in three solvents (separately) following maceration and soxhelt methods. The antimicrobial activity was tested using disc diffusion assay against a range of microorganisms along with the determination of minimum inhibitory concentration (MIC), while the antioxidant activity was tested following DPPH assay. Leaf extracts exhibited antimicrobial activity against all the three groups of microorganisms; results coincided with respective MIC. In general, the methanol extracts prepared through maceration favoured the determination of antimicrobial and antioxidant activities. Maximum values for phenolic and flavonoid contents were obtained in macerated methanol and ethyl acetate extracts, respectively. The statistical correlations exhibited the extent of the contribution of phenolic and flavonoid contents in antimicrobial and antioxidant activities and also indicated the involvement of other plant metabolites.