Studies On Chemical Constituents And Pharmacological Activities Of The Roots Of Polyalthia Laui

Polyalthia laui Merr. is one of the seven Polyalthia species growing in Hainan island,P.R.China. The genus is known for its folkloric applications against a number of ailments suchas stomachache, dysmenorrhea and pharynx neurosis et al. A literature survey indicated thatthere is no chemical and pharmacological study reported previously on P. laui. In order to takecomprehensive utilization, it is very useful for studies on chemical constituents and cytotoxicactivities of P. laui.The air-dried roots of the P. laui were crushed, and then extracted by75%ethanol (involume fraction). A dark ethanol extract was obtained after evaporation under reducedpressure. The extract was mixed with water, extracted by petroleum ether, chloroform, ethylacetate, respectively. The four fractions were respectively subjected to columnchromatography over macroporous resin, normal and reversed-phase silica gel, sephadexLH-20, preparation thin-layer chromatography and recrystallization repeatedly to obtain purecompounds. Their structures were established on the basis of extensive spectroscopic (IR,1D-NMR,2D-NMR, MS) data and X-ray diffraction analysis and by the comparison with thatreported in the literature. A test on cytotoxic activities(or anti-tumor activities) of differentfractions and some compounds by MTT method had been taken. The essential oil obtained bywater-steam distillation extraction of the leaves of P. laui was analyzed by gaschromatography-mass spectrometry (GC-MS).A total of22compounds were isolated and puried from the roots of the P. laui, Theircompounds were identified using the modern spectrum technology, X-ray and literaturecomparison method. Their structures were Darienine(1), Isooncodine(2), Onychine(3),5,8-dihydroxy-6-methoxy onychine(4), Kolavenic acid(5),2-oxo-kolavenic acid(6),(E)-ent-cleroda-3,13-diene-15,16-dioicacid(7),2-oxo-14,15-bisnor-3,11-ekolavadien-13-one(8),3,4-dihydroxy clerodan-13E-en-15-oicacid(9), Biscler odaneimide(10), Liridine(11), Liriod-enine(12), Oxostephanine(13), Polycarpol(14), Coumaroyl tyramine(15), Northalifoline (16),Vomifoliol(17),16-hydroxy cleroda-3,13E-dien-2-oxo-15-acid(18),(Z)-ent-cleroda-3,13–dien-2-oxo-15,16-dioic acid(19),16-oxocleroda-3,13E-dien-15-oic acid(20)、Solidagonal acid methyl ester(21),1(10)-Aristolen-2-one(22). Compound (18) and compound (19) were twonovel diterpenoids, compounds7、9、15-17was isolated from Annonaceae family for the firsttime, all compounds were isolated for the first time from this plant material. The structure ofDarienine (1) was confirmed by X-ray diffraction analysis, The anti-tumor activities ofcompound1-8were studied by the MTT method. Compounds1、5-7showed low inhibitoryactivities against SPC-A-1and SGC-7901human tumor cells, compounds5-7displays weakinhibitory activities towards K562human tumor cells, but compounds2-4had no inhibitoryactivities against the three human tumor cells. The essential oil obtained by water-steamdistillation extraction of the leaves of P. laui was analyzed by gas chromatography-massspectrometry(GC-MS). Forty compounds were characterized representing67.03%ofcompounds presents in the oil.