Studies On The Chemical Constituents From Seeds Of A Thai Mangrove Plant,Xylocarpus Granatum

Mangrove plants are found in the intertidal zone of tropical and subtropical oceans.They are salt-tolerant higher woody or shrub plants.The ecological community composed mainly of mangrove plants is called mangrove.Because of the unique growth environment of mangrove plants,their secondary metabolites are not only varied in variety and quantity,but also extensive and diverse in activity.At present,natural products isolated from mangrove plants are important sources for the discovery of new drug lead compounds.In this study,the chemical constituents from the seeds of Xylocarpus granatum,a mangrove plant of Melia from Thailand were isolated and identified.TLC,HPLC-PDA,LC-MS and other methods were used to trace the target compounds.A total of 25 monomer compounds were isolated and purified by normal and reversed phase silica gel column chromatography and HPLC.structures were identified by high/low resolution mass spectrometry(HLS),nuclear magnetic resonance(NMR)spectroscopy and single crystal X-ray diffraction.There were 5 new compounds and 20 known compounds.The five new compounds include:two Maxicanolide type limonins(R-3、R-5);one phragmalins type limonin(R-2);one Andirobin type limonin(R-1);one other limonoids(R-4).The 20 compounds include:limonins(15):Granatumin W(R-6)、Xyloccensin P(R-7)、Xyloccensin Q(R-8)、xyloccensin O(R-9)、xyloccensin S(R-10)、xyloccensin T(R-11)、Protoxylocarpin G(R-12)、Andirolide N(R-13)、Methyl 8α-hydroxy-8,30-dihydroangolensate(R-14)、godavarins B(R-15)、swietenine(R-16)、febrifugin(R-17)、Swietenine Acetate(R-18)、6-deoxydestigloylswietenine(R-19);others(5):Seneganolide A(R-20)、4-Hydroxymellein(R-21)、Mycoepoxydiene(R-22)、Piperine(R-23)、spiropreussomerin A(R-24)、(+)-(R)-de-O-Methyllasiodiplodin(R-25).Antitumor activity of the compounds were tested and no significant activity was found.At the same time,the new compounds were tested for the agonistic activity of progesterane X receptor(PXR).The results showed that Maxicanolide limonoid R-3 exhibited significant PXR excitatory activity at 10.0μM.