Studies On The Chemical Constituents Of Hypericum Japonicum

Hypericum japonicum, a one-year growth herb, which usually grows 10~40cm high and blooms from May to June, is widely distributed in the southern arid regions of the Yangtze valley of China.Presently, injections or syrups of the ethanol extracts of hypericum japonicum have been produced for the treatment of hepatitis. The extracts of hypericum japonicum had also been reported to display bioactivities of antibacterial, antitumor and cardiovascular system protecting. Recently, the chemical constituents of this plant have been investigated and a considerable amount of compounds have been isolated from hypericum japonicum. However, it is still not sufficient for the research of its active compounds. Consequently, in order to illuminate the active constituents in operation, it is necessary to make further investigation of this plant.Here, a systematical investigation of the chemical constituents of hypericum japonicum has been carried out. Twenty compounds were isolated from the whole plant of hypericum japonicum by column chromatographies on silica gel, Sephadex LH-20, macroporous resin D-101 and polyamide. And on the basis of classical chemical methods and modern chromatographic techniques, seventeen of them were identified. Among the seventeen compounds identified, one was found to be a new compound and seven were isolated from this plant for the first time.The new compound was elucidated to be 5,6-dihydroxy-4,4,5,6,6a-pentahydro -2H-cyclopenta[b]furan-2-one-hydrate(TJH-16).In addition, the known compounds included two xanthones, seven flavonoids, two sterols, three organic acids, and two hydroxybenzenes. Their structures were identified as follows: isojacareubin(TJH-l), quercetin(TJH-2), kaempferol(TJH-3), quercetin-7-O-α-L-rhamnoside(TJH-4), quercitrin(TJH-5), isoquercitrin(TJH-6), miguelianin(TJH-7), bijaponicaxanthone(TJH-8), 3,8"-biapigenin(TJH-9), betulinic acid(TJH-10), stigmasterol(TJH-11), stigmasterol-3-O-β-D-glucopyranoiside(TJH-12),isocaffeic acid(TJH-13), l,2-benzenediol(TJH-14), 2,5-dihydroxybenzoic acid (TJH-15) and l,2,3-benzenetriol-2-acetate(TJH-17). Among these known compounds identified, TJH-7, TJH-9, TJH-12, TJH-13, TJH-14, TJH-15, TJH-17 were isolated from this plant for the first time.A review had also been given in this paper on the recent advance of the chemical and pharmacological research of Hypericum genus.