Stilbene and its oligomers including their glucosides are occurring in the particular families such as Dipterocarpaceae, Vitaceae, Cyperaceae, Leguminosae and Gnetaceae. Resveratrol (tran-3,5,4'-trihydroxystilbene), one of the stilbenes, has recently been drawn to attentions because of its various biological properties such as anti-oxidative, antimutagenic, and an inducer of phase II drug-metabolizing enzymes. The further wide-ranged biological activities like antifungal, cytotoxicic, anti-inflammatory, antivirus and antibacterial have been still more examined. Dipterocarpaceaeous plants are well known to rich resource of various resveratrol oligomers. A genus Vatica comprising 65 species belongs to the largest subfamily Dipterocarpoideae in Dipterocarpaceae, most of which distributes in Southeast Asia. Although some phytochemicals in a few families were disclosed, the systematical phenolic compositions have not been discussed yet. The structural elucidation of resveratrol oligomers in some Dipterocarpaceous plants [Vateria, Hopea, Vatica, and Shorea] and some biological properties of the characterized oligomers were discussed in our previous papers. The different oxidative condensation of resveratrol admitted the oligomers to a variety of frameworks in the family like dihydrobenzofuran ring, benzocyclopentane ring, dibenzo[2.1]octadiene, dibenzobicyclo[3.2.1]octadiene, dibenzobicyclo[3.3.0]octadiene and tribenzobicyclo[3.3.2]octatriene system. The unusual spectroscopic properties have been observed in the complex stereo structures of some stilbene oligomers caused by anisotropy and fixation of phenyl group and so on. The phytochemical and biological interest in resveratrol oligomers in the family led us the current study of Vatica pauciflora (Korth.). The present research deals with the isolation and structure elucidation of new resveratrol oligomers [pauciflorols A-C (1-3), and isovaticanols B (6) and C (8)] and the glucosides [pauciflorosides A (11), B (13) and C (14)] along with 17 known resveratrol cognates (4,5,7,9,10,12 and 15-25) and bergenin (26). Some unusual spectroscopic properties observed in isovaticanol B (6), vaticanol B (7) and isovaticanol C (8) in NMR spectrum are also comprehensively discussed.
