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Guava leaves (Psidium guajava linn), is belong to the myrtaces family and psidium genera,which contain ingredients include flavonoids, terpenoids and phenolic compounds. Currently the main method of islation is silica gel, macroporous resins, sephadex gel and preparative liquid separation.As a liquid-liquid partition chromatography without solid carrier, high-speed countercurrent chromatography(HSCCC),possess characteristics of no dead adsorption,large-scale preparation, simple operation.It has been widely used in the separation and purification of natural products. This article combies column chromatography with high-speed countercurrent chromatography, to provide a new technical means of guava leaf components separation. Meanwhile, the experimental study of the effects of guava leaves flavonoids on proliferation and consumption servant of HepG2cells above high glucose concentrations and glucose, to further expand of its pharmacological activity.1ReviewSummarize the application of high-speed countercurrent chromatography in natural products and solvent selection methods, the two-phase solvent system used in HSCCC can be broadly divided into four categories:non-polar system, weak polar system, medium polar system and hydrophilic system. corresponding to separation of different polar compounds. The main compounds of guava leaves contain flavonoids, terpenoids, phenolic acids and volatile oil components, which are mainly triterpenoids ursolic acid and oleanolic acid type are the typical structure of triterpenoids, miscellaneous sources as a class of terpenes structure with terephthalic aldehyde, flavonoids including quercetin, kaempferol, morin, myricetin and their glucoside, pharmacological studies indicate that guava leaves have hypoglycemic, lipid-lowering, anti-bacterial, anti-virus and other pharmacological effects.2Extraction and separation of Guava leavesThis experiment adopt silicon gel column chromatography, using different proportions of petroleum ether, ethyl acetate, ethyl acetate and methanol as elution, after recrystallization, Guavadial and β-sitosterol are got from Fr2and Fr3.Fr7is seperated by high-speed countercurrent chromatography with petroleum ether-ethyl acetate-methanol-water (3:1.5:0.5:3, v/v/v/v) for the two-phase solvent system to afford fractions and then by preparative high performance liquid phase to afford kaempferol and apigenin. Fr8is first separated with petroleum ether-ethyl acetate-methanol-water (1:4:1:4, v/v/v/v) as eluent and then blown out,the elution then separated by petroleum ether-ethyl acetate-methanol-water (3:1:1:3. v/v/v/v),and the purified by sephadex LH-20, finally this compound is identified as quercetin.3Guava leaves flavonoids’ effect on HepG2cells above high glucose concentrationThis research in five flavonoid compounds including quercetin-3-O-β-D-glucopyran-oside, quercetin-3-O-β-D-xylopyranosyl glycoside, quercetin-3-O-β-D-pyranarabinoside, quercetin-3-O-α-L-furan arabinoside and quercetin,mainly involves in aglycone effect of Human hepatoma cells HepG2cell proliferation above high sugar concentration conditon. Results shows that quercetin-3-O-β-D-glucopyranoside (75μg/L), quercetin-3-O-α-L-furan arabinoside (10μg/L) groups have significant effect of promoting cell proliferation, shows the potential of antidiabetic.
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