Trinop Promgool, Orasa Pancharoen and Suwanna Deachathai

pp. 459 - 463

Abstract

Phytochemical investigation of Cassia alata Linn. led to the isolation of six known anthraquinones: aloe-emodin (1),
emodin (2), ω-hydroxyemodin (3), lunatin (4), physcion (5), and ziganein (6), six flavonoids: apigenin (7), 7,4′-dihydroxy-5-
methoxyflavone (8), diosmetin (9), kaempferol (10), luteolin (11), and trans-dihydrokaempferol (12) as well as one stilbene,
trans-resveratrol (13). Their structures were elucidated on the basis of spectroscopic methods, including UV, IR, NMR and
MS. Nine compounds (3-9 and 12-13) were reported for the first time as metabolites of C. alata. Compound 2 exhibited strong
antibacterial activity against methicillin resistant S. aureus (MRSA)-SK1 and B. cereus TISTR 687 with MIC values of 4 and
8 µg/mL, respectively. Compound 10 was found to exhibit antioxidative activity with IC₅₀ value of 9.67 µM that was three
times stronger than that of ascorbic acid (IC₅₀ 25.41 µM)

Keywords

• Cassia alata Linn.
• anthraquinones
• flavonoids
• antibacterial
• antioxidation