THE isolation and structure of citronin, a new flavanone glycoside from the peel of immature Ponderosa lemons (Citrus limon Burm. f. ponderosa Hort.) was reported some time ago by Yamamoto and Oshima1. From chemical and spectroscopic evidence it was concluded that citronin is 2′-methoxy-5,7-dihydroxyflavanone 7-rhamnoglucoside (I) and thus belongs to the rather uncommon group of flavonoids having a substituent at position 2′. In attempting to obtain this compound from samples of both mature and immature Ponderosa lemons, under conditions approximating those of Yamamoto and Oshima, it has been our experience that the only glycoside which can be isolated easily in crystalline form is neohesperidin (II). This was identified by elementary analyses, mixed melting point determination, infra-red spectrum, preparation of the phenylhydrazone derivative and isolation of the aglycone hesperetin from the hydrolysate. Neohesperidin differs from hesperidin only in the position of attachment of rhamnose to glucose2: