Enzyme mediated-transesterification of verbascoside and evaluation of antifungal activity of synthesised compounds

Enzymatic acylation of verbascoside, a polyhydroxylated natural product, has been reported in this study using five different commercial lipases and taking p-nitrophenyl alkanoates as acyl donors. Out of these enzymes, the immobilised Candida antarctica lipase B was found as the enzyme of choice. Mono- and di-acylated products were formed, with mono as major product indicating high regioselective nature of such transformations. A series of acyl esters of verbascoside have been synthesised by this enzymatic transesterification methodology. The lipophilicity of the synthesised analogues was also checked. The analogues were further subjected to synergistic antifungal activity with amphotericin B (AmB) against Candida albicans. Fourfold reduction in minimum inhibitory concentration of AmB was observed with few synthesised analogues such as verbascoside 400-octanoate (3b), verbascoside 400- palmitate (3d) and verbascoside 400,40 -dipalmitate (4d) at a concentration of 0.5mg/mL.Integrative Medicine (IIIM) and University of Pretoria.http://www.tandfonline.com/loi/gnpl20hb2017Chemistr

Plasmodium falciparum Malaria Vaccines and Vaccine Adjuvants

International audienceMalaria-a parasite vector-borne disease-is a global health problem, and Plasmodium falciparum has proven to be the deadliest among Plasmodium spp., which causes malaria in humans. Symptoms of the disease range from mild fever and shivering to hemolytic anemia and neurological dysfunctions. The spread of drug resistance and the absence of effective vaccines has made malaria disease an ever-emerging problem. Although progress has been made in understanding the host response to the parasite, various aspects of its biology in its mammalian host are still unclear. In this context, there is a pressing demand for the development of effective preventive and therapeutic strategies, including new drugs and novel adjuvanted vaccines that elicit protective immunity. The present article provides an overview of the current knowledge of anti-malarial immunity against P. falciparum and different options of vaccine candidates in development. A special emphasis has been made on the mechanism of action of clinically used vaccine adjuvants

Enzyme mediated-transesterification of verbascoside and evaluation of antifungal activity of synthesised compounds

<div><p>Enzymatic acylation of verbascoside, a polyhydroxylated natural product, has been reported in this study using five different commercial lipases and taking <i>p</i>-nitrophenyl alkanoates as acyl donors. Out of these enzymes, the immobilised <i>Candida antarctica</i> lipase B was found as the enzyme of choice. Mono- and di-acylated products were formed, with mono as major product indicating high regioselective nature of such transformations. A series of acyl esters of verbascoside have been synthesised by this enzymatic transesterification methodology. The lipophilicity of the synthesised analogues was also checked. The analogues were further subjected to synergistic antifungal activity with amphotericin B (AmB) against <i>Candida albicans.</i> Fourfold reduction in minimum inhibitory concentration of AmB was observed with few synthesised analogues such as verbascoside 4″-octanoate (<b>3b</b>), verbascoside 4″-palmitate (<b>3d</b>) and verbascoside 4″,4′-dipalmitate (<b>4d</b>) at a concentration of 0.5 μg/mL.</p></div

Polyhydroxy-<i>N</i>-alkyl-2-pyrrolidinones as a new class of glycolipid analogues with immune modulation potential

<p></p> <p>A focused library of novel <i>N</i>-alkyl-2-pyrrolidinone derivatives <b>3a–e</b> was synthesized from d-galactose employing a multistep chiron approach. These novel glycolipid analogues exhibited lipopolysaccharide-mediated splenocyte proliferation with no apparent toxicity against murine splenocytes. Various immunological assays on dendritic cells, macrophages, and human peripheral blood mononuclear cells have ascertained the immunostimulatory activity of these new glycolipid analogues.</p

Design and synthesis of ring C opened analogues of α-santonin as potential anticancer agents

Here we describe ring opening reaction of a novel halo triene derivative viz., (3S, 5aS)-8- chloro-3a, 4, 5, 5a-tetrahydro-3, 5a, 9-trimethylnaphtho [1, 2-b] furan-2(3H)-one of α- santonin upon nucleophillic attack with alcohols. Halo-triene was synthesized from α- santonin upon reaction with vilsmeier reagent. The synthesised compounds from ring opening reaction were evaluated for anticancer activity against a panel of four human cancer cell lines (A-549, THP-1, HCT-15, and IMR-13). Most of the compounds exhibited promising anticancer activity against all cancer cells in vitro; however compound. 3d with benzyl substitution showed most potent anticancer activity with an IC50 value of 0.3 μM, 0.51 μM, 0.6 μM and 0.23 μM against A-549, THP-1, HCT- 116 and IMR-13 cell lines respectively.http://link.springer.com/journal/442017-09-30hb2017ChemistryChemical PathologyGenetic