องค์ประกอบทางเคมีจากลำต้นเถาช้างและฤทธิ์ทางชีวภาพ / ปิยนุช ทองผาสุก = Chemical constituents from Strychnos vanprukii stem and their biological activities / Piyanuch Thongphasuk
Phytochemical study of the stem of Strychnos vanprukii Craib yielded a new isopimarane diterpenoid, 7β-hydroxyisopimara-8,15-dien-14-one, and a new gluco-indole alkaloid, 3,4-dehydropalicoside, together with five other alkaloids: palicoside, 3,4,5,6-tetradehydropalicoside, akagerine, 17-O-methylakagerine and strychnocarpine. Two new lignans, strychnoside and vanprukoside, were also isolated together with the known lyoniresinol-3-O-β-glucopyranoside. Three phenolic compounds: pyrocatechuic glucoside, syringic and vanillic acid, a cyclitol compound (bornesitol), mixture of β-sitosterol and stigmasterol and mixture of their glucosides were also found. Three lignans displayed antioxidant activity more active than ascorbic acid. All of the tested compounds showed acetylcholinesterase inhibitory activity less active than galanthamine and possessed no antimicrobial activity against tested microorganisms and cytotoxic activity against melanoma B16 cell line.