Study On Chemical Components And Neuronal Protective Activity From Ethyl Acetate Fraction Of Syzygium Jambos

Objective: Syzygium jambos(L.)Alston also named rose apple,belongs to the family of Myrtaceae,the genus of S..The dried pericarp of S.jambos,recorded in“Supplements to Compendim of Materia Medica” and firstly appeared in Luo Fu Zhi.It has the functions of warming the stomach and strengthening the spleen,warming the lungs and relieving cough,breaking blood and reducing swelling.And it is untilized to treat some syndrome,such as,hiccough with stomach cold,diarrhea due to spleen deficiency,chronic dysentery,lung deficiency and cold cough,and itiching tumor.Modern pharmacological studies have shown that it has hypoglycemic,antioxidant,antipyretic-analgesic,anti-inflammatory and antibacterial effects.Our study mainly focused on the chemical components and biological activity of the ethyl acetate fraction of the peel of S.jambos,in order to enrich the phytochemical diversity and clarify the material basis for the efficacy of the peel of S.jambos.Methods: The dried peel of S.jambos(15 kg)was extracted with 70% ethanol(60 L)for four times,2 h each time,and concentrated under reduced pressure to yield a crude extract,which was extracted with petroleum ether,ethyl acetate and n-butanol,successively.The compounds were isolated and purified by various chromatographic methods(including silica gel,Sephadex LH-20,ODS and semi-preparative HPLC and other column chromatography)combined with separative methods of preparation of thin layer chromatography(PTLC)and recrystallization from the ethyl acetate fraction.The structures of the obtained compounds were analyzed and identified by NMR and other spectroscopic methods,and their biological activities were also evaluated.Results: A total of 32 compounds were isolated and identified from the ethyl acetate fraction of the 70% ethanol extract of the peel of S.jambos,including a new compound.Compounds 1-6 are triterpenoids,Compounds 7-8 are steroids,Compound 9-14,21 are organic acids,Compounds 15-20 are esters,Compound 22-24 are pyranones,Compound 25-26 are lignans,Compounds27-32 are other compounds.The biological activity assay results showed that compounds 1,2,4,5,9,11,14,15,19,25 have certain protective effect on HT22 cell damage induced by oxygen and glucose deprivation(OGD)injury model in vitro.Conclusion: This study led to the isolation of 32 compounds from the peel of S.jambos,including a new compound,which enriched the diversity of chemical composition of the peel of S.jambos.Activity screening found that some of triterpenoids,organic acids and their esters could to some extent protect neuronal cell damage induced by hypoxia and glucose deficiency in the model of cerebral apoplexy in vitro,suggesting that these compounds might improve the symptoms of hypoxia and glucose deficiency after cerebral ischemia,which provided a scientific basis for further study on the pharmacodynamic substance basis of the peel of S.jambos.