Chemical Constituents Of Two Plants From The Genus Vatica

For centuries, natural products, especially constituents of medicinal plants have been an important drug resource. In developing countries, plants are the main source of drugs.80% of the world's population depends on plants and plant extracts to maintain health and life. Natural medicines, which benefit the health of people, have received increasing attention. Bioactive components of plants usually are normally regarded as one resource of important lead compounds for drug development. In some cases, the active compounds can even be developed into clinical drugs or healthy products, such as taxol and resveratrol.Resveratrol oligomers and their derivatives have drawn considerable attention because of their various bioactivities such as antibacterial, antioxidant, anti-HIV and anti-tumor and other biological activities. Plants from the genus Vatica of Dipterocarpaceae family are rich resources of resveratrol oligomers. The genus Vatica comprises over 60 species, most of which distribute in Southeast Asia. Chemical compositions of plants of this genus have been studied. Resveratrol oligomers, terpenes and coumarins are the major constituents. There are no phytochemically investigations of Vatica mangachapoi and Vatica parvifolia yet, which are tropical plants of Hainan island of China.In order to search for structurally new and biologically active metabolites, we have studied the chemical constituents of Vatica mangachapoi and Vatica parvifolia. Forty-two compounds are isolated by the chromatography techniques including Si gel.CC., ODS, Sephadex LH-20 and HPLC. The structures were elucidated on the basis of spectral experiments such as ESI-MS, NMR, IR, UV, CD and literature search. Four new compounds were discovered, a novel skeleton included. Two new Resveratrol dimers (1 and 2) that co-exist with their known congeners (3-27) were isolated from the stem wood of Vatica mangachapoi. Antioxidant properties of the polyphenols were evaluated using four different (DPPH and ABTS radical scavenging as well as ORAC and FRAP) assays. Most of the polyphenols in the plant were significantly antioxidant with the magnitude comparable to those of ascorbic acid and resveratrol, two co-accessed positive controls.Phytochemical examination of the branches and twigs of the tropical plant Vatica parvifolia resulted in the isolation of two novel oligostilbenes along with thirteen known oligostilbenes. All of the isolated phytochemicals were screened for their xanthine oxidase (XO) and acetylcholinesterase (AChE) inhibitory activities. Vaticanol A (20) showed moderate inhibitory acticity against XO. Vaticahainol B (28), vaticanol E (21), pauciflorol B (38) and vatdiospyroidol (23) exhibited significantly high activities against AChE.At last, research on the resveratrol oligomers from Vatica plants was briefly reviewed.