We have previously proposed that the BlmIV and BlmIII non-ribosomal peptide synthetases are involved in the formation of the bithiazole moiety of the anti-tumor drug bleomycin in Streptomyces verticillus ATCC15003. We report here the identification and characterization of an oxidation domain in BlmIII. The oxidation domain shows local homology to a family of oxidoreductases and is present in al...

High initial Mn(II) concentration results in accumulation of a Mn(III) tartrate complex in the growth medium of Phanerochaete chrysosporium. Since Mn(III) is the major oxidant in ligninolysis by manganese peroxidase, the role of accumulated complex should not be neglected when degradation experiments by a crude culture filtrate are performed. To study the Mn(III) complex oxidative potential it ...

phenylazo and benzothiazolylazo derivatives of trifluoroacetylacetone andhexafluoroacetylacetone have been synthesized and characterized. analytical and spectral datarevealed the existence of phenylazo derivatives in the intramolecularly hydrogen-bonded ketohydrazoneform while the benzothiazolylazo derivatives in the azo-enol form. the monobasicbidentate coordination of the phenylazo derivative...

2-Chloroquinoline-3-carbaldehyde 1 reacts with 2-cyanoacetohydrazide in ethanol to result in 1-[1-aza-2-(2-chloro(3quinolyl))vinyl]-2-cyanoacetamide 2. Phenyl isothiocyanate added to a stirred solution of compound 2, sulphur and triethylamine in a mixed solvent of dimethylformamide : ethanol to result in N-[1-aza-2-(2-chloro(3-quinolyl))vinyl](4amino-3-phenyl-2-thioxo(1,3-thiazoline-5-yl)) carb...

In the course of our study on an alternative synthesis of ( + )-epiderstatin, we found some interesting observations, which helped us for preparing epiderstatin analogues. We developed a new methodology for the syntheses of epiderstatin analogues by using an unusual reaction to study their structure-activity relationship. During study, we found that epiderstatin is not a real inhibitor of signa...

Apratoxins are cytotoxic natural products originally isolated from marine cyanobacteria that act by preventing cotranslational translocation early in the secretory pathway to downregulate receptor levels and inhibit growth factor secretion, leading to potent antiproliferative activity. Through rational design and total synthesis of an apratoxin A/E hybrid, apratoxin S4 (1a), we have previously ...

A flow-electrolytic cell that consists of a bare gold wire or of different thiol-compound-modified gold electrodes (such as 2,4-thiazolidinedione, 2-mercapto-5-thiazoline, 2-mercaptothiazoline, l-cysteine, thioglycolic acid) was designed to be used in a voltammetric detector to identify l-selenomethionine and Se-methylseleno-l-cysteine using high-performance liquid chromatography. Both l-seleno...