Study On The Chemical Constituents From The Fruits And The Flowers Of Aquilaria Sinensis

Aquilaria sinensis (Lour.) Gilg, an endemic and rare medicinal plant in China, is a tropical, subtropical evergreen tree belongs to the genus Aquilaria of the family Thymelaeaceae, and it’s also the only plant resource of Chinese eaglewood. Chinese eaglewood, the famous traditional Chinese medicine, is the wood containing black resin of A. sinensis (Lour.) Gilg, which possessed various functions such as sedative, analgesic, and digestive. It is very important to study the bioactive components from A. sinensis for the purpose of development and sustainable utilization of this plant resource.Our previous work showed the 95% EtOH extract from fruits of A. sinensis had inhibitory activity towards human gastric carcinoma (SGC-7901) and human hepatoma (SMMC-7721) cell lines, with the IC50 values of 12.1μg·mL-1 and 8.4μg·mL-1 respectively. In an effort to search for the bioactive constituents, the constituents from the fruits and flowers of A. sinensis were isolated and purified by column chromatography, and their structures were identified by physicochemical and spectroscopic methods (including MS, IR, UV, 1D and 2D-NMR, etc). Twelve compounds were isolated from the fruits of A sinensis collected from Hainan. And their structures were elucidated as hexanorcucurbitacinⅠ(1), cucurbitacin I (2), cucurbitacin D (3),3α,16α,20(R),25-tetrahydroxy-2,11,22-trioxocucurbita-5,23(E)-diene (4), neocucurbitacins B (5), indolyl-3-carboxylic acid (6),6-hydroxy-2-[2-(4-hydroxyphenyl)ethyl]chromone (7), genkwanin (8),4’,5-dihydroxy-3’,7-dimethoxyflavone (9), apigenin-7,4’-dimethylethers (10), (β-sitosterol (11) andβ-daucosterol (12). Compounds 1～7 was obtained from the genus Aquilaria of the family Thymelaeaceae for the first time. Compounds 1～5 were a series of known cucurbitacins. Compounds 1,2,4,5 showed significant inhibitory activity towards chronic myelogenous leukemia (K562), human gastric carcinoma (SGC-7901) and human hepatoma (SMMC-7721) cell lines. A references survey revealed that cucurbitacins posessed anti-tumor activity, and our study also confirmed that the anti-tumor activity of the EtOH extract from the fruits of A. sinensis was concerned with the anti-tumor cucurbitacins in it. Furthermore, we also analyzed the chemical constituents of the volatile oils from the flowers and fruits of A. sinensis by GC-MS. Both the volatile oils contain some fragrant constituents. In recent years, A. sinensis have been planted widely in Guangdong and Hainan provinces, but its fruits and flowers have not yet been exploited. So the present study could provide the scientific basis for its exploitation.