Studies On The Chemical Constituents And Bioactivities From The Fruits Of Garcinia Bracteata

Garcinia bracteata,a Guttiferae Garcinia plant,which ripe fruits can be eaten raw and processed into spices,mainly distributed in southern Yunnan to southern Guangxi.It has been reported that compounds,such as xanthones and biphenyl derivatives,isolated from stems,branches and leaves of G.bracteata,and showed different degrees of inhibition on tumor cells.In order to exploit the resources of Garcinia plant better,we launched a systematic study to investigate the chemical constituents and pharmacological of G.bracteata.By means of a variety of modern chromatographic separation techniques,24compounds?1-24?,including 15 xanthones?1-15?and 9 polycyclic polyprenylated phloroglucinols?PPAPs??16-24?,were isolated from the ethyl acetate extraction of G.bracteata.Among them,9 compounds?4-6,11,18-19,21-23?are determined as new compounds.Compounds 4-6 are new pernylated xanthones,compound 11 is a new caged polyprenylated xanthones,compounds 18-19,21-23 are new PPAPs.Garcibracteamone H?22?and Garcibracteamone I?23?posses an unprecedented caged 5-oxatetracyclo-[7.4.1.1^9,12.0^3,7]pentadecane new skeleton.Anti-tumor activities of isolated compounds were tested by CCK-8 method aganist T98,HepG2,and MCF-7.Most of the caged polyprenylated xanthones compounds showed different degrees of inhibition on tumor cells.Among them,compound 8?Doitunggarcinone K?and 14?Neobractatin?showed good anticancer activity,and showed strong activity against the tested three tumor cells,with IC₅₀values of 3.47?M,5.51?M,5.87?M and 3.21?M,5.11?M,6.27?M,respectively.In addition,compounds 7,9,10,13 also showed moderate cytotoxic activity.The LPS-induced mouse mononuclear macrophage leukemia cell RAW264.7cells were used to establish an inflammatory model.The Griess method was used to study the effect of the compounds,which were isolated from the G.bracteata fruit,on the release of NO from RAW264.7.Most of the caged polyprenylated xanthones isolated from fruits showed good anti-inflammatory activity,among which compound2?5-O-methylxanthone?,compound 3?10-O-methylmacluraxanthone?,compound 7?Bractatin?,Compound9?Isobractatin?,compound12?8?-methoxy-8,8a?-dihydrobractatin?,Compound 15?Neobractatin?have a good inhibitory effect on NO release from RAW 264.7 with IC50 values of 14.19?M,16.39?M,1.22?M,6.07?M,8.96?M,1.77?M,respectively.Those results showed that the fruits of G.bracteata contain many compounds with structural diversities,and most of the caged polyprenylated xanthones exhibit good anti-inflammatory and anti-tumor activities.It indicates that G.bracteata can be further researched in the development of new anti-tumor and anti-inflammatory drugs.