Flavonoids are plant secondary metabolites that are well known for their health-promoting properties as nutraceuticals in diets. Bioavailability and biological activities of flavonoids vary among the individual subclasses with different patterns of substitution, inclusive of glycosylation, to their basic structures. Many flavonoids exist as glycosides in plants. This study investigated the possibility of glycosylation of flavonoids through biotransformation using filamentous fungi as whole-cell biocatalysts. Microbial transformations of ten flavonoids (four flavones, four flavonols, a flavanone, and an aurone) were performed in cultures of Mucor hiemalis KCTC 26779. As a result, a flavonoid glycoside was obtained which has not been described previously. The chemical structure of this product was elucidated as 6,2′-dimethoxyflavonol-3-O-β-d-glucopyranoside by analyzing 1-dimensional and 2-dimensional-nuclear magnetic resonance spectral and high-resolution electrospray ionization mass spectral data. This compound could be useful for further biological and bioavailability studies, as well as expanding the library of flavonoid derivatives.

黄酮类化合物是植物的次生代谢产物，以其作为健康食品的营养品而具有促进健康的特性。类黄酮的生物利用度和生物活性在具有不同取代模式（包括糖基化）的基本结构的各个亚类之间有所不同。许多类黄酮以糖苷形式存在于植物中。这项研究调查了通过使用丝状真菌作为全细胞生物催化剂进行生物转化来进行类黄酮糖基化的可能性。在Mucor hiemalis的培养物中进行了十种黄酮（四种黄酮，四种黄酮醇，一种黄烷酮和一个金酮）的微生物转化KCTC26779。结果，获得了先前未描述的类黄酮糖苷。通过分析一维和二维核磁共振光谱和高分辨率电喷雾电离质谱数据，阐明了该产品的化学结构，为6,2'-二甲氧基黄酮醇-3- O-β - d-吡喃葡萄糖苷。该化合物可用于进一步的生物学和生物利用度研究，以及扩大类黄酮衍生物的文库。