Study On The Bioactive Constituents Of Mango Leaves(Mangifera Indica L.)

Mango（Mangifera indica L.）,belongs to the family Anacardiaceae,which is widely distributed all over the world and its origin is South Asia.In the traditional Chinese medicine,its kernel could be applied to cure for asthma,anthelmintic,dysentery,laxatives,aphrodisiacs,and tonics,its juice could be applied to treat sinuses,and its leaves could be used to treat heat stagnation pain,bloating,infantile malnutrition,diabetes and so on.Previous studies have shown that the bark,nuts,peel,and leaves of mango,have rich phenolic compounds,inchuding phenolic acids,xanthones,flavonoids,benzophenones and so on.The polyphenols presented in mango have showed various bioactivities,such as antioxidant,antidiabetic,anti-inflammatory,antimicrobial,immunomodulatory,antipyretic and analgesic activity.In this study,the leaves of mango were extracted with 70% ethanol-water.The concentrated solution was successively extracted by different polar solvents.The in vitro α-glucosidase inhibitory,antioxidant and NO inhibitory activities were evaluated for the fractions.The results showed that the EtOAc fraction and normal butanol fraction exhibited pronounced α-glucosidase inhibitory,antioxidant and antiinflammatory activities.The bioactive fraction were isolated and purified by SiO2,HP-20,ODS,Sephadex LH-20,and Rp-HPLC to obtain 56 compounds,and their structures were elucidated on the basis of physical and chemical properties and spectroscopic data（UV,1D NMR,2D NMR and MS）.They were identified as 2,4,4′,6-tetrahydroxy-3′-methoxybenzophenone-3-β-D-glucopyranoside（1*）,2,4,4′,6-tetrahydroxybenzophenone-3-C-（2-O-p-hydroxybenzoyl）-α-D-galactoside（2）,foliamangiferoside A1（3）,2,4,4′,6-tetrahydroxybenzophenone-3-C-（6-O-phydroxybenzoyl）-β-D-glucopyranoside（4）,2,4′,6-trihydroxy-4,3′-dimethoxybenzophenone-3-β-D-glucopyranoside（5）,2,4,4′,6-tetrahydroxybenzophenone-3-β-D-glucoside（6）,2,4′,6-trihydroxy-4-methoxybenzophenone-3-C-β-D-glucopyranoside（7）,4,4′,6-trihydroxybenzophenone-2-O-ɑ-L-arabinofuranoside（8*）,4’,6-dihydroxy-4-methoxybenzophenone-2-O-β-Dglucoside（9）,4,4’,6-trihydroxybenzophenone-2-O-β-D-glucoside（10）,2,4′,6-trihydroxy-4-methoxybenzophenone（11）,iriflophene（12）,4,4′,6-trihydroxybenzophenone-2-O-（2″）,3-C-（1″）-1″-desoxy-β-fructofuranoside（13*）,4′,6-dihydroxy-4-methoxybenzophenone-2-O-（2″）,3-C-（1″）-1″-desoxy-ɑ-L-fructofuranosi de（14*）,aquilarinoside A（15）,4′,6-dihydroxy-4-methoxybenzophenone-2-O-（2″）,3-C-（1″）-1″-desoxy-β-fructopyranoside（16*）,4,4′,6-trihydroxybenzophenone-2-O-（2″）,3-C-（1″）-1″-desoxy-β-fructopyranoside（17*）,2,4′,6-trihydroxy-4-methoxy benzophenone-3-C-（2-O-p-hydroxybenzoyl）-α-D-galactoside（18*）,quercetin-3-O-β-D-xylopyranoside（19）,quercetin-3-O-β-D-glucoside（20）,quercetin-3-O-α-Lrhamnoside（21）,quercetin-3-O-β-D-arabinoside（22）,quercetine-3-O-β-Dgalactoside（23）,quercetin-4’-O-β-D-glucoside（24）,luteolin-7-O-β-D-glucoside（25）,isovitexin（26）,isoswertisin（27）,vitexin（28）,quercetin（29）,3’,5’-dimethoxy-4’,5,7-trihydroxyflavone（30）,mangiferin（31）,4’-O-p-hydroxybenzoylmangiferin（32）,hypericin（33）,taxifolin（34）,amentoflavone（35）,arjunolic acid（36）,madecassic acid（37）,2α,3α,23-trihydroxyurs-12,20（30）-dien-28-oicacid（38）,lupeol（39）,8,26-cyclo-urs-21-en-3β,20β-diol（40）,7R,8S-dihydrodehydrodiconiferyl alcohol 9’-O-β-D-glucopyranoside（41）,（-）-ecoisrariciresinol-9-O-β-D-glucopyranoside（42）,（-）-isolariciresinol 2a-O-β-D-glucoside（43）,threo-1-（4-hydroxy-3-methoxyphenyl）-2-[4-（3-hydroxypropyl）-2-methoxyphenoxy]-1,3-propanediol（44）,erythro-1-（4-hydroxy-3-methoxyphenyl）-2-[4-（3-hydroxypropyl）-2-methoxyphenoxy]-1,3-propane diol（45）,ethyl gallate（46）,gallic acid（47）,isovanillic acid（48）,syringic acid（49）,vanillic acid（50）,protocatechuic acid（51）,methyl-2-O-β-D-glucopyranosylbenzoate（52）,breynioside A（53）,5-n-heptadecylresorcinol（54）,daucosterol（55）,β-sitosterol（56）,respectively.Also,in vitro α-glucosidase inhibitory,antioxidant and anti-inflammatory activities of compounds 1-45 were evaluated.Comparing with acarbose(IC₅₀ 185.25 ± 6.00 μM),compounds 1,22,29,31,32,36 and 37 exhibited pronounced α-glucosidase inhibitory activities,and the IC₅₀ values were of compounds 1(IC₅₀ 284.93 ± 20.29 μM),22(IC₅₀ 171.05 ± 34.79 μM),29(IC₅₀ 92.15 ± 5.56 μM),31(IC₅₀ 300.05 ± 7.86 μM),32(IC₅₀ 272.00 ± 36.00 μM),36(IC₅₀ 239.6 ± 25.00 μM),37(IC₅₀ 297.37 ± 8.12 μM),respectively.Compounds 11,19-25,29,31-34,41-43 showed pronounced antioxidant activities in the DPPH assays,and compounds 20(IC₅₀ 9.80 ± 0.14 μM),23(IC₅₀ 11.15 ± 0.40 μM)and 32(IC₅₀ 4.91 ± 0.07 μM)exhibited the strongest activity.Most compounds showed pronounced NO inhibitory activity compared to indomethacin,such as compounds 19(IC₅₀ 21.64 ± 4.11 μM),29(IC₅₀ 3.05 ± 0.26 μM),30(IC₅₀ 2.85 ± 0.34 μM),33(IC₅₀ 5.76 ± 0.15 μM)and 34(IC₅₀ 33.09 ± 5.45 μM),respectively.