The Chemical Constituents Of The Extarcts Of Chloroform And Ethyl Acetate From The Flower Of Pitaya And Fragmentation Pathways Of Some Compounds Of Flavonoid, Triterpenoid And Lignan By Electrospray Ionization Multi-stage Tandem Mass Spectrometry

Pitaya, a member of Hylocereus Brittonet Rose and Selenicereus Brittonet Rose, was mainly distributed in the area of Costa Rica, Mexico, Cuba, and Vietnam. In China, it was mainly distributed in Guangxi, Gangdong, Taiwan, Hainan and Fujian provinces. It was reported that Pitaya has lots of pharmacology effects, such as protecting stomach, anti-free radical,anti-oxidation, anti-senescence, precauting hypertensive, et al. Up to date, several researches on the constituents and pharmacological activities of Pitaya have been reported in abroad, but there were few reports about the constituents of Pitaya at home. Our previous work had researched on the Petrol Ether and n-Butanol of the constituents of this plant. In order to further investigate the chemical constituents of Pitaya, the extarct of Chloroform and Ethyl acetate in the flower of Pitaya was separated in this dissertantion.The dissertation was composed of three parts. In the first part, it was a review about the research progress of Pitaya, which mainly included its chemical constituents and pharmacology activities. In the second part, the chemical constituents of chloroform and ethyl acetate from the flower of Pitaya were isolated. In the last part, the fragmentation pathways of some compounds of flavonoid, triterpenoid and lignan were discussed by electrospray ionization mass spectrometry.The flower of Pitaya was extracted by 75% ethanol, and then ethanolic extract was concentrated to a brown viscous mass, which was successively partitioned by petrol ether, chloroform, ethyl acetate and n-butanol. The extract of the chloroform fraction was separated by column chromatography of silica gel to give six parts (c-Fr.Ⅰ, c-Fr.Ⅱ, c-Fr.Ⅲ, c-Fr.Ⅳ, c-Fr.Ⅴand c-Fr.Ⅵ). Then they were purified mainly by column chromatograph on silical gel, respectively. Compounds 13,16,14,15 and 7 were got from c-Fr.Ⅰ, c-Fr.Ⅱand c-Fr.Ⅲby column chromatography of silica gel and recrystallization. Compounds 6,8,10,5 and 12 were obtained by column chromatography of silica gel from and c-Fr.Ⅳand c-Fr.Ⅴ.The extract of ethyl acetate fraction was subjected to column chromatography of silica gel to give five parts (e-Fr.Ⅰ, e-Fr.Ⅱ, e-Fr.Ⅲ, e-Fr.Ⅳand e-Fr.Ⅴ). Then they were purified mainly by column chromatograph on silical gel, Sephadex LH-20, RP-C18, respectively. The isolation of e-Fr.Ⅲhas led to compound 9 and 11 by column chromatography of silica gel. Compound 2,3 and 4 were gained by column chromatography of silica gel, Sephadex LH-20 and RP-C18 from e-Fr.Ⅳ. The extract of n-butanol fraction was subjected to column chromatography of silica gel to give five parts (t-Fr.Ⅰ, t-Fr.Ⅱ, t-Fr.Ⅲ, t-Fr.Ⅳand t-Fr.Ⅴ). Compound 1 were gained by column chromatography of silica gel, Sephadex LH-20 and RP-C18 from t-Fr.Ⅴ.The structures of fifteen compounds were identified on the basis of UV, IR, MS,1H NMR and 13C NMR data and by comparison of them with the references. They are kaempferol 3-O-α-L-rhamnosyl(1'''''''→6''''')-β-D-galactosyl(1'''''→6'''')-β-D-galactoside-7-O-α-L-rhamn osyl(1''''''→6''')-β-D-galactosyl(1'''→6'')-β-D-galactoside(1), isorhamnetin 3-O-glucoside (2), isorhamnetin-3-O-β-D-galactoside (3), kaempferol-7-O-α-L-rhamnopyranoside (4), uracil (5), dibutylphthalate (6), 1-decyl-2-butane phthalate (7), P-sitosterol (8), daucosterol (9), (14RS)-(10E,12E)-14-hydroxy-9-oxo-10,12-octadecadienoic acid (10), tricosanoic acid 2, 3-dihydroxypropyl ester (11), n-pentacosanoic acid (12), n-tetracosanoic acid (13), n-dotricontanoic acid (14), n-triacontanol (15). Compound 1 was identified as a new compound by searching data-base of SciFinder Scholar. It needs more spectroscopic data to determine the structures of the other one compound.All identified compounds, except for dibutylphthalate andβ-sitosterol, were isolated from the plant for the first time.In order to discuss the fragmentation pathways of some compounds of flavonoid, triterpenoid and lignan, the electrospay ionization tandem mass spectrometry ESI-MSn experiment was investigated. According to some interesting neutral losses, the fragmentation mechanisms of compounds were explored. It was found that the flavonoid compounds were easy to lose CO and H2O, the situation was also often accompanied with de-embrittlement; 5 triterpenoids fragmentations in the electrospay ionization tandem mass spectrometry ESI-MSn experiment were simple, oleanene acid and ursene acid gave a prominent [M-H]- ions monitored in the negative ion mode,β-amyrin andβ-amyrone gave a prominent [M+H]+ ions monitored in the negative ion mode; and the two lignan compounds gave a prominent [M-H]- ions monitored in the negative ion mode.