Eleven edible leafy vegetables of India have been analysed for their free radical-scavenging activity in different systems of assay, e.g. DPPH radical-scavenging activity, superoxide radical-scavenging activity in riboflavin/light/NBT system, hydroxyl radical-scavenging activity, and inhibition of lipid peroxidation induced by FeSO4 in egg yolk. Total antioxidant activity was measured, based on the reduction of Mo(VI) to Mo(V) by the extract and subsequent formation of green phosphate/Mo(V) complex at acid pH. The extracts were found to have different levels of antioxidant properties in the systems tested. Considering all the activities, it can be said that Ipomoea reptans has good activity amongst the eleven plant materials screened for their antioxidant properties. Lowest activity was found in Nyctanthes arbortristis. Many flavonoids and related polyphenols contribute significantly to the total antioxidant activity of many fruits and vegetables. However, there was no correlation between antioxidant activity and total phenol/flavonoid content. © 2006 Elsevier Ltd. All rights reserved.

BRATATI DE

Botany

N DASGUPTA

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Food Chemistry

Phoenix sylvestris is an underutilized seasonal fruit in West Bengal, India. Methanol extract and extracts after alkaline hydrolysis of the mesocarp tissue of full-mature edible fruits of P. sylvestris were analyzed by GC-MS following a metabolomics approach. The fractions were tested for their antioxidant and inhibitory properties against the two key enzymes involved in diabetes, α-amylase, and α-glucosidase. Total 71 metabolites belonging to organic acids, amino acids, sugars, sugar alcohols, fatty acids, and phenols were identified in the methanol extract and in fractions after saponification. All the extracts and fractions showed high antioxidant, α-glucosidase, and α-amylase inhibitory activities. Sugars like raffinose (IC 50 = 0.36 μM), sucrose (IC 50 = 0.51 μM), trehalose (IC 50 = 0.85 μM), and phenols like taxifolin (IC 50 = 0.31 μM), benzoic acid (IC 50 = 2.74 μM) inhibited only the enzyme α-amylase. Phenolic components which inhibited both the enzymes were caffeic acid (IC 50 = 1.42 μM for α-amylase and IC 50 = 1.8 μM for α-glucosidase), 3, 4-dihydroxy benzoic acid (IC 50 = 0.23 μM for α-amylase and IC 50 = 2.58 μM for α-glucosidase), and quinic acid (IC 50 = 4.91 μM for α-amylase and IC 50 = 4.95 μM for α-glucosidase). Ferulic acid (IC 50 = 0.52 μM) and 4-hydroxycinnamic acid (IC 50 = 0.23 μM) inhibited only α-glucosidase. This study suggested that the metabolites present in the fruit mesocarp tissue showed the potential antioxidant activity and properties to inhibit the enzymes α-amylase and α-glucosidase. Further in vivo study is to be carried out to prove the efficacy of the fruits. Abbreviations: FM: crude methanol extract; SI: ethyl acetate extract after alkaline hydrolysis step I; SII: ethyl acetate extract after alkaline hydrolysis step II. © 2017 Taylor & Francis Group, LLC.

Fulltext

International Journal of Food Properties

Metabolite profiling, antioxidant activity, and glycosidase inhibition property of the mesocarp tissue extracts of sugar date palm [Phoenix sylvestris (L.) Roxb.] fruits

A heteroglycan (PS) isolated from the mycelia of Pleurotus ostreatus was found to consist of l-fucose, d-mannose, and d-glucose in a molar ratio of nearly 1:2:3. On the basis of acid hydrolysis, methylation analysis, periodate oxidation, and NMR studies (1H, 13C, TOCSY, DQF-COSY, NOESY, ROESY, HSQC, HMBC, and DEPT), the structure of the repeating unit of the PS was determined. The repeating unit had a branched backbone composed of (1→6)-linked α and β d-glucose and (1→2)-linked α-l-fucose. Branching occurred at C-4 position of (1→6)-linked α-d-glucopyranosyl residue with terminal β-d-mannose and C-3 position of (1→6)-linked β-d-glucopyranosyl residue with (1→6)-α-d- mannopyranosyl moiety terminated by α-d-glucose. The structure of the repeating unit of the PS was proposed as: →6)-β-D-Glcp-(1→6)- α-D-Glcp-(1→2)-α-L-Fucp-(1→3↔1α-D-Glcp- (1→6)-α-D-Manp 4↔1β-D-Manp. The antioxidant properties of the PS were studied. The scavenging activity of hydroxyl free radicals whose EC50 value of PS at 943 μg/mL was determined. Further, EC 50 value of the PS at 53 μg/mL was observed for scavenging activity of superoxide free radicals. Chelating effects (54.82%) of ferrous ions were observed at 1 mg/mL of the PS. © 2012 Elsevier Ltd. All rights reserved.

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ISSN	0308-8146