Constituents of Fermented Male Flowers of Alnus sieboldiana (Betulaceae)

Fractionation of the ethyl acetate crude extract of the fermented male flowers of Alnus sieboldiana resulted in the isolation of two diarylheptanoids and six flavonoids. Yashabushidiol A, yashabushidiol B and naringenin were known constituents of the male flowers of A. sieboldiana while kaempferol, quercetin, pinocembrin dimethyl ether, 5,7-dimethoxy-3-hydroxyflavanone and 5,7-dimethoxy-3-hydroxyflavone were isolated for first time from the fermented male flowers of A. sieboldiana. The isolated compounds were characterized using NMR and HRMS and compared with available literature.

Comparative Study of the Volatile Components of Fresh and Fermented Flowers of Alnus sieboldiana (Betulaceae)

Analysis of the volatile components present in the fresh male and female flowers and young leaves shows that 2-phenylethanol is the major component in all these three organs, which play a significant role in the strong resinous aromatic odor. The male flowers contained styrene as a second major compound. The level of styrene does not affect the male flowers odor concentration. The level of β-phenylethyl cinnamate and trans-methyl cinnamate in the fermented male flowers decreased as the fermentation time increased. This was due to the Penicillium enzymatic action on the fermented male flowers.