Studies on physiologically active substances in citrus peel. Part VIII. Structure and hypotensive effect of flavonoid glycosides in sudachi peelings. II.
Sudachiin A was isolated from the green peels of Citrus sudachi Hort. ex Shirai. This structure was deduced to be sudachitin 4′-β-d-glucoside by means of its spectra and degradation; this was confirmed by the synthesis of the one from sudachitin 7-benzyl ether and α-acetobromoglucose via several steps. 4′,5,7-Trihydroxy-3′,6,8-trimethoxyflavone 7-glucoside (sudachitin 7-β-d-glucoside), which was isolated from Sideritis leucantha Cavanilles, was also synthesized from sudachitin and α-acetobromoglucose in a similar manner.