Coloradocin was isolated from a fermentation broth by adsorption onto Amberlite XAD-2. The activity was eluted in MeOH and purified by gel filtration on Shephadex LH-20, followed by liquid-liquid chromatography on diol-bonded silica gel. The last two steps in the purification of this antibiotic included reverse-phase chromatography on C18-bonded silica gel and countercurrent chromatography on a...

The comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC × GC/TOFMS) has been used to characterize a crude oil and a source rock extract sample. During the process, a series of pairwise components between monocyclic alkanes and mono-aromatics have been discovered. After tentative assignments of decahydronaphthalene isomers, a series of alkyl decalin isomers have...

A convergent, stereocontrolled route to either antipode of the cell adhesion inhibitor, peribysin E, has been achieved from carvone. Highlights of the synthesis include a Diels-Alder reaction to generate a cis-decalin framework, followed by semipinacol-type ring contraction to secure the stereochemistry of the C7 quaternary center. Potential mechanistic pathways for the critical ring contractio...

Thermophilic bacteria play an important role in aroma formation during pile-fermentation process of dark tea. With the aim to reveal impact thermophilic on volatile compounds tea, Bacillus licheniformis (thermophilic bacteria) were inoculated into sun-dried green tea for spontaneous fermentation. In this study, headspace solid phase microextraction combined gas chromatography mass spectrometry ...

Bifunctional catalysis combining acidic catalysts and sulfide active phases is usually related to hydrocracking which balances the hydrogenation function of a NiMo (NiW) alumina supported zeolite. The discovery sulfur-resistant for selective ring opening (SRO) an important challenge refiners, considering future legislation on cetane index diesel fuels. In present work, we studied properties var...