Four new p-aminoacetophenonic acids, named (2E)-11-(4′-aminophenyl)-5,9dihydroxy-4,6,8-trimethyl-11-oxo-undec-2-enoic acid (1), 9-(4′-aminophenyl)-3,7dihydroxy-2,4,6-trimethyl-9-oxo-nonoic acid (2), (2E)-11-(4′-aminophenyl)-5,9-O-cyclo4,6,8-trimethyl-11-oxo-undec-2-enoic acid (3) and 9-(4′-aminophenyl)-3,7-O-cyclo-2,4,6trimethyl-9-oxo-nonoic acid (4), were isolated from an endophyte Streptomyce...

7-(D-5-Amino-5-carboxy-valeramido)-3-(acetylhydrazido)-8-oxo-5-thio-1-azabicyclo [4,2,0]-oct2-ene-2-carboxylic acid (1). 7-(D-5-Amino-5-carboxy-valeramido)-3-(substitutedarylacetylhydrazido)8-oxo-5-thio-1-azabicyclo[4,2,0]-oct-2-ene-2-carboxylic acid.(2-5). 7-(D-5Amino-5carboxyvaleramido)3(2'substituted aryl-3'-chloro-4'-oxo-azetidin-1'-yl)-acetylamino]-8-oxo-5-thio-1azabicyclo[4,2,0]-oct-2-ene...

Accurate ab initio calculations at the B3LYP/6-311 G** level have been performed on anionic and neutral structures of 4,5-dihydro-5-oxo[1,2,4]triazolo[1,5-a]pyrimidine, 4,7-dihydro-7-oxo[1,2,4]triazolo[1,5-a]pyrimidine, and 4,5-dihydro-7-amino-5-oxo[1,2,4]triazolo[1,5-a]pyrimidine compounds. The quality of the theoretical results has been tested against the experimental X-ray structures for the...