Biotransformation of furanocoumarins by fungi: preparation of imperation analogs.

Imperation analogs have the furanocoumarin skeleton, with the isopentenyl group, which displayed significant bioactivities. The biotransformation of furanocoumarins imperation, isoimperation and phellopterin (1-3) by fungi has been proved to be an efficient method for the structural modification. Ten transformed furanocoumarin analogs were obtained by fungal biotransformation, including one new highly oxygenated furanocoumarin (4c).

Biotransformation of resibufogenin by Actinomucor elegans.

Resibufogenin (RB), a major bioactive bufadienolide, has the potential anticancer activity. In the present work, biotransformation of RB by Actinomucor elegans AS 3.2778 yielded five products, namely 3-oxo-resibufogenin (1), 3-epi-resibufogenin (2), 3-epi-12-oxo-hydroxylresibufogenin (3), 3α-acetoxy-15α-hydroxylbufalin (4), and 3-epi-12α-hydroxylresibufogenin (5), respectively.

Microbial transformation of resibufogenin by Curvularia lunata AS 3.4381.

In this paper, the microbial transformation of resibufogenin by Curvularia lunata AS 3.4381 was investigated, and four transformed products were isolated and characterized as 3-epi-resibufogenin (2), 12α-hydroxy-3-epi-resibufogenin (3), 12-oxo-16β-hydroxy-3-epi-resibufogenin (4), and 12β,15-epoxy-3-epi-bufalin-14,15-ene (5). Among them, 4 and 5 are new compounds, and isomerization, hydroxylation, and oxidation reactions in microbial transformation process were observed.

Novel microbial transformation of resibufogenin by Absidia coerules.

Resibufogenin is one of the major active components of the Chinese medicine ChanSu. In this paper, microbial transformation of resibufogenin by Absidia coerules AS 3.3382 was investigated and five metabolites were isolated and identified as 5beta-hydroxy-resibufogenin (2), 3-epi-resibufogenin (3), 3alpha-hydroxy-15-oxo-14alphaH-bufa-20, 22-dienolide (4), 3alpha,14alpha,15beta-trihydroxy-bufa-20, 22-dienolide (5) and 3-epi-15beta-hydroxy-bufalin (6).

Novel microbial transformation of resibufogenin by Fusarium solani.

In this paper, microbial transformation of resibufogenin by Fusarium solani AS 3.1829 was investigated, and five transformed products were isolated and identified as 3-ketone-resibufogenin (2), 3-one-cyclic 3-(1,2-dimethyl-1,2-ethanediylacetal)-resibufogenin (3), 3-dimethoxyl-resibufogenin (4), 3-epi-resibufogenin (5), and 3-epi-15α-hydroxy-7βH-bufalin (6), respectively. Among them, 3, 4, and 6 are new compounds, and the rare double oxidization of C-3 was reported.

Two new lavandulyl flavonoids from Sophora flavescens.

Two novel lavandulyl flavonoids, (2S)-7-methoxyl-4",5"-dihydroxynorkurarinone (1) and (2S)-6"-hydroxynorkurarinone-7-O-beta-D-galactoside (2), were isolated from the rhizome of Sophora flavescens. Their structures were elucidated by spectral methods, including 2D NMR spectroscopy. Both compounds showed cytotoxic activity against Hela cells, with 2 being more active than 1.

Microbial transformation of dehydroandrographolide by Cunninghamella elegans.

The biotransformation of dehydroandrographolide (1) by Cunninghamella elegans was performed and four transformed products were obtained. Based on their extensive spectral data, the structures of these metabolites were identified as 3-oxo-dehydroandrographolide (2), 3-oxo-2beta-hydroxy-dehydroandrographolide (3), 3-oxo-8beta,17alpha-epoxydehydroandrographolide (4), 3,19-dihydroxy-7,11,13-ent-labdatrien-15,16-olide (5), respectively. Among them, products 3-5 are new compounds.