Praveen Dhyani

Optimization extraction conditions for improving phenolic content and antioxidant activity in Berberis asiatica fruits using response surface methodology (RSM).

This study for the first time designed to optimize the extraction of phenolic compounds and antioxidant potential of Berberis asiatica fruits using response surface methodology (RSM). Solvent selection was done based on the preliminary experiments and a five-factors-three-level, Central Composite Design (CCD). Extraction temperature (X1), sample to solvent ratio (X3) and solvent concentration (X5) significantly affect response variables. The quadratic model well fitted for all the responses. Under optimal extraction conditions, the dried fruit sample mixed with 80% methanol having 3.0 pH in a ratio of 1:50 and the mixture was heated at 80 °C for 30 min; the measured parameters was found in accordance with the predicted values. High Performance Liquid Chromatography (HPLC) analysis at optimized condition reveals 6 phenolic compounds. The results suggest that optimization of the extraction conditions is critical for accurate quantification of phenolics and antioxidants in Berberis asiatica fruits, which may further be utilized for industrial extraction procedure.

Assessment of Nutritional and Antioxidant Potential of Selected Vitality Strengthening Himalayan Medicinal Plants

Three Himalayan medicinal plants (Habenaria intermedia, H. edgeworthii, and Roscoea procera), widely used in vitality strengthening Ayurvedic formulations in India, were assessed for nutritional phytochemical constituents, and antioxidant activity. These target species emerged as a good source of minerals and possessed important micro elements. Individually, H. intermedia contained a high content of total phenols, thiamins, tannins, and calcium; R. procera was rich in potassium and iron content; and H. edgeworthii emerged as a good source of sodium. While various antioxidant assays provided evidences on the antioxidant potential of target species, greater antioxidant potential of H. intermedia as compared to the other two species was revealing. This study, therefore, highlighted the possibilities of harnessing nutritional and antioxidant potential of these species.

Ginkgo biloba flavonoid glycosides in antimicrobial perspective with reference to extraction method

The present study aims to investigate the effect of extraction method on the recovery of flavonoid glycosides, antimicrobials and antioxidants from Ginkgo leaves collected from six different locations in Uttarakhand, Indian Himalaya. Four extraction methods, namely maceration, reflux, shaker and soxhlet were considered, where reflux extracts showed higher antimicrobial antioxidant activity and higher content of flavonoid glycosides. The reference standards of Ginkgo flavonoid glycosides (quercetin, kaempferol and isorhamnetin) and crude extracts were tested for their antimicrobial activity against gram positive and gram negative bacteria and fungi following disc diffusion method and minimum inhibitory concentration (MIC). All the test microorganisms were observed to be inhibited significantly by Ginkgo flavonoids in plate based assays. Correlation coefficients exhibited the extent of contribution of flavonoid glycosides in antimicrobial activity and confirmed the reflux method as a potential method for extraction. Moreover, antioxidant activity as measured by DPPH assay was also found to be higher in reflux method. Significant variation (p < 0.05) in the flavonoid glycosides among the locations was also observed and sample collected from GB6 location was found to be the best for quercetin and isorhamnetin, while GB5 for kaempferol. Significant correlation (r < 0.05, r < 0.001) was obtained while developing the relationship between total flavonoid glycosides and antimicrobials. The present study, thus suggests the reflux method of extraction to be the best for maximum recovery of flavonoid glycosides with higher antioxidant and antimicrobial activities from Ginkgo extract.

Diversity of bioactive compounds and antioxidant activity in Delicious group of apple in Western Himalaya

Apple contributes significantly to the livelihood and health of the people living in Himalayan regions. Among others, the Delicious group of apple is known for their health promoting and income generating attributes. However, the systematic investigation on morphological and phytochemical attributes of the apple growing in Indian Himalayan region is poorly known. An altitude-dependent variation in the fruit quality traits and phytochemical diversity was observed. The Royal Delicious was found rich in total tannin, flavonoids, flavonols, antioxidant activity [2,2-azinobis (3-ethylbenzothiazoline-6-sulphonic acid), 2,2-Diphenyl-1-picryhydrazyl, Ferric reducing antioxidant power], procyanidin B2, phloridzin and gallic acid; Red Delicious for total phenol and epicatechin and Golden Delicious for chlorogenic acid. The cultivar and altitude-dependent variation of phenolic profile in peel and pulp portion emphasizes genotype-specific biosynthesis of phenolic compounds in regulatory mechanisms. It is suggested that selection of suitable altitude and cultivars is required for harnessing the maximum phytochemical and antioxidant activity for benefits to human consumption.