ABSTRACT
The total phenolic content and antioxidant activities of the acetone extract and derived fractions from the walnut (Juglans regia) pellicle were estimated. The BuOH fraction exhibited the strongest antioxidant activity with the highest phenolic content. A phytochemical investigation of this fraction led to the isolation of three tannins, 2,3-hexahydroxydiphenoylglucose (1), pedunculagin (2) and 2,3,4,6-tetragalloylglucose (3). Pedunculagin showed high content and powerful activity, which implied that this compound plays an important role in the antioxidant activity of the walnut pellicle.
Subject(s)
Antioxidants/chemistry , Juglans/chemistry , Plant Leaves/chemistry , Tannins/chemistry , Molecular StructureABSTRACT
Fifteen compounds were isolated from the seed coat of Juglans regia by silica gel, MCI gel and Sephadex LH-20 gel column chromatography, as well as high preparative performance liquid chromatography. Their structures were identified as salidroside (1), (6S, 9S)-roseoside (2), (6S, 9R)-roseoside (3), blumenol C glucoside (4), byzantionoside B (5), 5-hydroxy-2-methoxy-1, 4-naphthoquinone (6), gallic acid (7), glycerol 1-(9Z-octadecenoate)-2-(9Z, 12Z-octadecadienoate)-3-(9Z, 12Z, 15Z-octadecatrienoate) (8), glycerol 1, 2, 3-tri-(9Z, 12Z-octadecadienoate) (9), glycerol 1, 2, 3-tri-(9Z, 12Z, 15Z-octadecatrienoate) (10), glycerol 1-hexadecanoate-2, 3-di-(9Z, 12Z-octadecadienoate) (11) on the basis of EI-MS, FAB-MS and NMR spectra. Moreover, 35 volatile compounds were identified by GC-MS.