%0 Journal Article
%T Biotransformation of 3-hydroxydibenzo-¦Á-pyrone into 3,8 dihydroxydibenzo-¦Á-pyrone and aminoacyl conjugates by Aspergillus niger isolated from native¡°shilajit¡±
%A Islam
%A Aminul
%A Ghosh
%A Runa
%A Banerjee
%A Dipankar
%A Nath
%A Piali
%A Mazumder
%A Upal Kanti
%A Ghosal
%A Shibnath
%J Electronic Journal of Biotechnology
%D 2008
%I Pontificia Universidad Cat¨®lica de Valpara¨ªso
%X ¡°shilajit¡± is a panacea in ayurveda, the indian traditional system of medicine. the major bioactives of ¡°shilajit¡± have been identified as dibenzo-¦Á-pyrones (dbps), its oligomers and aminoacyl conjugated derivatives. these bioactive compounds play a crucial role in energy metabolism in all animal cells including those of man. 3-hydroxydibenzo-¦Á-pyrone (3-oh-dbp), a key dbp component of ¡°shilajit¡± is converted, among other products, to another active dbp derivative, viz. 3,8-hydroxydibenzo-¦Á-pyrone, 3,8(oh)2-dbp, in vivo, when its precursor is ingested. 3,8(oh)2-dbp is then involved in energy synthesis in the mitochondria in the reduction and stabilization of coenzyme q10 in the electron transport chain. as the chemical synthesis of 3,8(oh)2-dbp is a complex, multi-step process and economically not readily viable, we envisioned the development of a process using microorganisms for bioconversion of 3-oh-dbp to 3,8(oh)2-dbp. in this study, the biotransformation of 3-oh-dbp is achieved using aspergillus niger, which was involved in the humification process on sedimentary rocks leading to ¡°shilajit¡± formation. a 60% bioconversion of 3-oh-dbp to 3,8(oh)2-dbp and to its aminoacyl derivatives was achieved. the products were characterized and estimated by high performance liquid chromatography (hplc), high performance flash chromatography (hpfc) and gas chromatography-mass spectrometry (gc-ms) analyses. among the aspergillus species isolated and identified from native ¡°shilajit¡±, a. niger was found to be the most efficient for this bioconversion.
%K coenzyme q10 reduction
%K electron transport chain humification
%K paleohumus.
%U http://www.scielo.cl/scielo.php?script=sci_abstract&pid=S0717-34582008000300001&lng=en&nrm=iso&tlng=en