Biotransformation of steviol derivatives by Aspergillus niger and Fusarium moniliforme

Abstract

Derivados do esteviol foram submetidos a biotransformações por fungos. O ent-11β,13-diidróxi-15,16-epoxicauran-19-oato de metila foi hidroxilado em C-11 por Aspergillus niger enquanto que o ácido ent-16β-hidróxibaierano-19-óico foi hidroxilado em C-6 e C-7 pelo Fusarium moniliforme. A hidroxilação em posições não ativadas do esqueleto carbônico é discutida tendo em vista as propriedades de importantes diterpenóides descritos na literatura.Steviol derivatives have been submitted to biotransformations by fungi. Methyl ent-11β,13-dihydroxy-15,16-epoxikauran-19-oate was hydroxylated at C-11 by Aspergillus niger, whereas ent-16β-hydroxybeyeran-19-oic acid was hydroxylated at C-6 and C-7 by Fusarium moniliforme. The hydroxylation at non-activated positions at the carbon skeleton is discussed in connection with the properties of important polyhydroxylated diterpenoids described in the literature.

Occurrence, Biological Activities and Synthesis of Kaurane Diterpenes and their Glycosides

“…[97]. Steviol derivatives, such as isosteviol (54) and the epoxykaurane 74, were submitted to biotransformations by the fungi Aspergillus niger and Fusarium moniliforme [98], leading stereo-and regioselectively to the hydroxylated compounds 75, 76 and 77.…”

Occurrence, Biological Activities and Synthesis of Kaurane Diterpenes and Their Glycosides

“…[97]. Steviol derivatives, such as isosteviol (54) and the epoxykaurane 74, were submitted to biotransformations by the fungi Aspergillus niger and Fusarium moniliforme [98], leading stereo-and regioselectively to the hydroxylated compounds 75, 76 and 77.…”

(–)‐Isosteviol as a Versatile Ex‐Chiral‐Pool Building Block for Organic Chemistry

“…Recent studies have also revealed that oxime 9a , lactams 57a – 57d , and nitriles 60a – 60e , obtained by microbial transformation with Absidia pseudocylindrospora and Aspergillus niger , exhibit suppressive effects on iNOS (induced nitric oxide synthase) expression, which plays a crucial role in inflammatory processes 50. Hydroxylation at the 6‐ and 7‐positions of dihydroisosteviol 5 (Scheme ) has been reported by de Oliveira et al51…”