Author
P.V. Srinivas
Bio: P.V. Srinivas is an academic researcher from Indian Institute of Chemical Technology. The author has contributed to research in topics: Oroxylin A & Rheum emodi. The author has an hindex of 17, co-authored 43 publications receiving 1114 citations.
Topics: Oroxylin A, Rheum emodi, Antibacterial activity, Acylation, Nitration
Papers
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TL;DR: The methanolic extract of rhizome of Himalayan rhubarb Rheum emodi displayed mild yeast as well as mammalian intestinal alpha-glucosidase inhibitory activity, but the isolation of several potent molecules in excellent yields showed that these compounds may have value in the treatment and prevention of hyperglycemia associated diabetes mellitus.
131 citations
TL;DR: It was observed that most of the derivatives displayed significant activity as compared to their parent compound (chrysin), and all the derivatives were screened for antibacterial activity against a panel of susceptible and resistant Gram-positive and Gram-negative organisms.
119 citations
TL;DR: In this investigation for the anticancer constituents from the hexane extract of this plant, a new sesquiterpene was isolated along with the known compounds costunolide, beta-cyclocostunolides, dihydro costunOLide and dehydro costuslactone, and all the compounds were tested for their in vitro cytotoxic activity.
87 citations
TL;DR: The bioassay-guided chemical examination of the rhizomes of R. emodi resulted in the isolation of two new oxanthrone esters and a new anthraquinone ether revandchinone-4, establishing new structures based on spectroscopic and degradative evidence.
83 citations
TL;DR: A bioguided extraction and fractionation of the petroleum ether extract of the berries of P. nigrum afforded compounds that were active against Bacillus subtilis, Bacillus sphaericus, and Staphylococcus aureus amongst Gram + ve bacteria, and Klebsiella aerogenes and Chromobacterium violaceum among Gram -ve bacterial strains.
80 citations
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TL;DR: In this paper, the authors described the methods used for free radical scavenging in both substrates as well as in specific cases of their application, such as superoxide radicals scavenging (O2·-), hydrogen peroxide scavenging(H2O2), hypochlorous acid scavenging, HOCl, and hydroxyl radical scavenges (HO), among them, among them are the methods that use azo-compounds to generate peroxyl radicals.
Abstract: Free radical generation is directly related with oxidation in foods and biological systems. Therefore, the search for methods to determine free radical scavenging is important. In this work are described the methods used for this purpose in both substrates as well as in specific cases of their application. The main methods comprise superoxide radicals scavenging (O2·-); hydrogen peroxide scavenging (H2O2); hypochlorous acid scavenging (HOCl); hydroxyl radical scavenging (HO.); peroxyl radical scavenging (ROO.), among them are the methods that use azo-compounds to generate peroxyl radicals, such as the ``TRAP'' method (Total Radical-Trapping Antioxidant Parameter) and the ``ORAC'' method (Oxygen-Radical Absorbance Capacity); the scavenging of radical cation 2,2-azinobis-(3-ethylbenzothiazoline-6-sulphonate) or the ABTS or the ``TEAC'' method (Trolox Equivalent Antioxidant Capacity); the scavenging of stable radical 2,2-diphenyl-1-picrylhydrazyl or DPPH . method and the scavenging of radical cation N,N-dime...
1,085 citations
TL;DR: Flavonoids are a family of plant-derived compounds with potentially exploitable activities, including direct antibacterial activity, synergism with antibiotics, and suppression of bacterial virulence, and recent advances towards understanding these properties are described.
985 citations
TL;DR: It is recommended that antioxidant capacity be expressed as vitamin C mg/100 g equivalent (VCEAC) using the ABTS assay, which can be used in both organic and aqueous solvent systems, employs a specific absorbance at a wavelength remote from the visible region, and requires a short reaction time.
Abstract: To express the antioxidant capacity of plant foods in a more familiar and easily understood manner (equivalent to vitamin C mg/100 g), two stable radical species, ABTS•- and DPPH•, commonly used for antioxidant activity measurements, were employed independently to evaluate their efficacies using apple polyphenolic extracts and seven polyphenolic standards including synthetic Trolox. Their antioxidant activities were expressed as vitamin C equivalent antioxidant capacity (VCEAC) in mg/100 g apple or mg/100 mL of the reference chemical compounds in 10 and 30 min using the ABTS•- and DPPH• scavenging assays, respectively. The antioxidant capacity of Gala apples and seven phenolic standards, determined by both ABTS•- and DPPH• scavenging assays, showed a dose−response of the first-order. Fresh Gala apples had a VCEAC of 205.4 ± 5.6 mg/100 g using the ABTS assay, and the relative VCEACs of phenolic standards were as follows: gallic acid > quercetin > epicatechin > catechin > vitamin C > rutin > chlorogenic ac...
889 citations
TL;DR: The state of the art with respect to the preparation and use of supported metal nanoparticles in catalysis is described, the main groups of such nanoparticles (noble and transitionMetal nanoparticles) are highlighted and future prospects are discussed.
Abstract: Metal nanoparticles have attracted much attention over the last decade owing to their unique properties as compared to their bulk metal equivalents, including a large surface-to-volume ratio and tunable shapes. To control the properties of nanoparticles with particular respect to shape, size and dispersity is imperative, as these will determine the activity in the desired application. Supported metal nanoparticles are widely employed in catalysis. Recent advances in controlling the shape and size of nanoparticles have opened the possibility to optimise the particle geometry for enhanced catalytic activity, providing the optimum size and surface properties for specific applications. This Review describes the state of the art with respect to the preparation and use of supported metal nanoparticles in catalysis. The main groups of such nanoparticles (noble and transition metal nanoparticles) are highlighted and future prospects are discussed.
680 citations
569 citations