A pathway for the biotransformation of the environmental pollutant and high-molecular weight polycyclic aromatic hydrocarbon (PAH) benzo[k]fluoranthene by a soil bacterium was constructed through analyses of results from liquid chromatography negative electrospray ionization tandem mass spectrometry (LC/ESI(-)-MS/MS). Exposure of Sphingobium sp. strain KK22 to benzo[k]fluoranthene resulted in t...

Rapid and highly efficient synthesis of 2- or 2,5-substituted 1,3,4-oxadiazoles by the condensation of aryl carboxylic acid hydrazides and orthoesters can be achieved under microwave irradiation using an unmodified commercial over in unsealed vessels.

In the title compound, C(17)H(12)O(4), the chromene unit is approximately planar, the maximum deviation from the mean plane being 0.0166 Å. The attached phenyl ring makes a dihedral angle of 53.2 (1)° with the fused ring system. The packing of the mol-ecules in the crystal structure is governed by C-H⋯O and O-H⋯O hydrogen-bonding inter-actions.

Cephalosporin acylase (EC 3.5.1.11) obtained from Kluyvera citrophila ATCC 21285 was found to catalyze synthesis of 7-[2-(2-thienyl)acetamido]-3-trifluoromethyl-3-cephem-4-carboxylic acid from methyl thienylacetate and dl-7-amino-3-trifluoromethyl-3-cephem-4-carboxylic acid. The enzymatically-synthesized compound showed [alpha]25 D + 42.7 degrees (c 0.058, MeOH) and its biological activity was ...