| Xylocarpus granatum Koenig, a marine mangrove plant mainly distributed along the shore of the Indian Ocean and sea shores of Southeast Asia, was one of the three species in the genus Xylocarpus (Meliaceae). The seed-coat of Xylocarpus granatum had applications in the treatment of hematodiarrhoea, and the kernel was made as invigoration. This plant was used as a folk medicine in Southeast Asia and Indian for the treatment of diarrhea, cholera, and fever diseases such as malaria and also as an antifeedant. Xylocarpus granatum was found to be rich in limonoids, which was a highly oxygenated nortriterpenoids with their structural features either containing or being derived from a precursor with a furanylsteroid skeleton. From 80's of 20th century, limonoids were recognized as natural compounds which had potential biological activities. They showed broad range of biological activities, such as anti-HIV, antimicrobial, anthelminthic, and anti-tumor. Animal experiments indicated that limonoids could inhibit the liver cancer, bowel cancer, mouth cancer and skin cancer which were induced by chemical materials, and nontoxic to animal model.There were few works previously reported about the chemical studies on the genus Xylocarpus, mainly focused on the seeds and the fruits of Xylocarpus granatum Koenig and Xylocarpus moluccensis Lam. So far, several kinds of compounds have been obtained from this genus, including limonoids, alkaloids, phenolic acids, flavanol, steroids, monoterpenes and some others. Among them limonoid was the major component of this plant. This thesis mainly studied the chemical composition of the seeds of Xylocarpus granatum, and screened the PPARγexcitement activity and antitumor activities on human immortalised myelogenous leukaemia line K562 cells of the obtained compounds.Objective: To study the components of the seeds of Xylocarpus granatum, and set up the effective extraction and separation methods of this genus. To establish the structures of the isolated pure compounds using spectroscopic techniques including UV, IR, 1H-NMR, 13C-NMR, HMQC, HMBC, 1H-1H COSY, NOESY, DEPT, HR FAB-MS and so on. To screen the activities of the compounds isolated from the above plant on PPARγand K562 tumor cells.Methods: Air-dried seeds of Xylocarpus granatum were pulverized and extracted with 95% ethanol for one week at room temperature, the residue was extracted again for two times. After evaporation of the solvent under reduced pressure, the residue was suspended in water and extracted with petroleum ether, dichloromethane and n-butanol in order, successively. The dichloromethane extract (65.8 g) was chromatographed on silica gel column and eluted using petroleum ether-acetone as mobile phase to yield 10 crude fractions (Frs. 1~10). Fr. 2 provided compound 1. Fr. 3 was subjected to repeat column chromatography to yield compound 1 and compound 7. Fr. 4 yielded white solid, and obtained compound 3 via repeatedly recrystallization. Fr. 5 were purified with semi-preparative HPLC (methanol-water, 60:40) to afford compound 2 and compound 5. Fr. 10 provided compound 4. Fr. 8 was re-chromatographed to yield compound 8. Fr. 6 was isolated by Silica gel column chromatography again and further purified with sephadex LH-20 to yield compound 6 and compounds 16~18. Fr. 7 was re-chromatographed over Silica gel and further purified with semi-preparative HPLC to yield compounds 9~11. Fr. 9 were re-chromatographed over Silica gel and further purified with sephadex LH-20 to yield compounds 12~15.The PPARγagitated activities and antitumor activities on K562 cells of compounds A~E were studied.Results:After systematically investigation on extraction of the seeds of Xylocarpus granatum, 18 compounds were obtained. These compounds were analysized on the basis of spectral analysis and the structures of 16 compounds were established, including eight limonoids, four protolimonoids, three sterols and one coumarin. They wereβ-sitosterol (1), xylocarpin H (2), daucosterol (4), xylomexicanin A (5), odoratone (6), ergosterol peroxide (7), xylogranatin D (9), xylocarpin G (10), xylomexicanin B (11), piscidinol G (12), hispidol B (13), scopoletin (14), spicatin (15), 7-deacetyl-7-oxogedunin (16), xylogranatin C (17), and 3β-detigloyoxy-2′-methylbutanoyloxy xylogranatin B (18).The PPARγagitated activity tests upon compounds A~E suggested that compound A had the strongest activity, while compound E had stronger activity under the lower concentration, weaker under the higher, which indicated that compound E had cytotoxicity.The results of antitumor activity indicated that these five compounds all had moderate antitumor activities under the higher concentration, with the loss of concentration, the activity weaken.Conclusion: We studied the chemical components of Xylocarpus granatum seeds. The results of our experiment indicated that the solvents and methods of extraction used in this experiment are practicable. Silica gel column chromatography, sephadex LH-20 column chromatography and preparative HPLC were carried out to obtain 18 compounds from the seeds of Xylocarpus granatum. Varieties of spectroscopic methods were used to elucidate the structures of 16 compounds. Among them, xylomexicanin A (5) and xylomexicanin B (11) were new compounds; odoratone (6), ergosterol peroxide (7), piscidinol G (12), hispidol B (13) and scopoletin (14) were obtained from the genus for the first time; 7-deacetyl-7-oxogedunin (16) was isolated from Xylocarpus granatum for the first time. Antitumor activity tests upon compounds A~E indicated that compound A had the strongest activity of tumor growth inhibition.
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