Microbial Transformation of Two Prenylated Naringenins

Microbial transformation of (±)-6-(1,1-dimethylallyl)naringenin (6-DMAN, 1) and (±)-5-(O-prenyl) naringenin-4′,7-diacetate (5-O-PN, 2) was performed by using fungi. Scale-up fermentation studies with Mucor hiemalis, Cunninghamella elegans var. elegans, and Penicillium chrysogenum led to the isolation of five microbial metabolites. Chemical structures of the metabolites were determined by spectral analyses as (±)-8-prenylnaringenin (3), (2S)-5,4′-dihydroxy-7,8-[(R)-2-(1-hydroxy-1-methylethyl)-2,3-dihydrofurano]flavanone (4), (±)-5-(O-prenyl)naringenin-4′-acetate (5), (±)-naringenin-4′-acetate (6), and (±)-naringenin (7), of which 5 was identified as a new compound.

Isolation and Characterization of Three Unrecorded Zygomycete Fungi in Korea: Cunninghamella bertholletiae, Cunninghamella echinulata, and Cunninghamella elegans

In a survey of undiscovered taxa in Korea, three zygomycete fungal strains–EML-W31, EML-HGD1-1, and EML-RUS1-1–were isolated from freshwater, grasshopper fecal, and soil samples in Korea. On the basis of the morphological characteristics and phylogenetic analysis of internal transcribed spacer and 28S rDNA, the isolates of EML-W31, EML-HGD1-1, and EML-RUS1-1 were confirmed to be Cunninghamella bertholletiae, Cunninghamella echinulata, and Cunninghamella elegans, respectively. These species have not been previously described in Korea.