Avance MHz NMR spectrometer with TMS as an internal standard. Downloaded by at March Natural Product Research MS analyses were performed at high resolution on an Clofarabine ultrOTOF”ESI”TOF Mass Spectrometer Bruker Daltonics . The MS analysis was aplished using collision energy of 5 eV. Optical rotation analysis was undertaken on a Jasco Digital Polarimeter DIP . HPLC chromatography was carried on a Shimadzu equipment using reverse phase column CLC”ODS mm Shimadzu.
CC was carried out on silica gel 0 F and 0 H . Precoated plates of silica gel 0 F were used for analytical purposes and the spots were detected with a UV lamp at and nm and by Gastrodin spraying with 0 H SO followed by heating. Cultivati extraction and isolation The Humicola strain was isolated from a Brazilian soil sample and classified as H. grisea var. thermoidea on the basis of morphological and physiological characteristics as described by Cooney and Emerson . The isolated strain is deposited at the Laboratory of Microbiology and Cellular Biolo University of Sa??o Paulo. The production of secondary metabolites was carried out by inoculation of rice medium with conidia g . Cultures were incubated for 0 days at 0 C. The metabolites were extracted through maceration with ethanol. The ethanol extract was filtered and concentrated under vacu furnishing the crude ethanol extrac which was partitioned with hexanes and ethyl aceta in sequence. This vidarabine 5536-17-4 procedure afforded and g of each fracti respectively.
The ethyl acetate fraction was subjected to vacuum liquid chromatography over silica gel 0H and eluted with a mixture of hexanes”EtOAc in the order of increasing polarity to yield a total of eight fractions. The fifth subfraction was again submitted to vacuum liquid buy Raltegravir chromatography and eluted with a mixture of hexanes”EtOAc in the order of increasing polarity to yield a total of eight fractions. The third subfraction was flash-chromatographed over silica gel 0, using an isocratic mobile phas which gave 6 fractions. Fractions werebined and analysed by HPLC. Multiple injections ofbined fractions obtained from flash chromatography onto a reverse phase column CLC”ODS mm Shimadzu was carried o and elution was aplished with methanol/water at a flow rate of mL min over 3 m thereby yielding the-lactam derivative .-oxoethyl)-dihydropyridin-one : white sol m.p. C, UV : max and nm; IR : max and /cm; H-NMR and. 3 C-NMR.
HREIMS: m/z 0fifi. Molecular modelling procedures and prediction of the biological activity spectrum Conformational search was performed on the-lactam structure by means of the systematic searching method using the Merck molecular force field molecular mechanics mod implemented in the Spartan software . The molecule was then fully optimised in the gas phase at the LYP/ G level of calculation. Downloaded by at March W.J. Andrioli The prediction of the possible biological activity spectrum was performed with the PASS archaea server. PASS is a tool that predicts the possible biological effects of apound on the basis of the structural formula using MNA descripto thus suggesting that the biological activity is a function of the chemical structure. The PASS algorithm method estimates the biological activity byparing the structure of a newpound with a training .