Research And Development Of Antibacterial And Hypoglycemic Active Constituents Of Rhodomyrtus Tomentosa(Ait.)Hassk

Objective:To research and develop the constituents of antibacterial activity and hypoglycemic activity constituents from the leaves of Rhodomyrtus tomentosa.Methods:The compounds were isolated by solvent extraction,Sephadex LH-20,chromatography method of silica gel,MCI,ODS,and semi-preparative HPLC.The constituents were identited by spectral data（IR,UV,MS,1D and 2D NMR）.Some of the compounds isolated from R.tomentosa were evaluated the inhibitory effects of Staphylococcus aureus,Enterococcus faecium,Escherichia coli,Propionibacterium acnes and Clostridium difficile by the microdilution method,and some were evaluated the inhibitory activity ofα-glucosidase in vitro.Results:Compounds 1-32 were isolated from the ethyl acetate of R.tomentosa,and they were identified as:rhotomentosones A-D（1-4）,（-）-rhodomyrtosone C（5）,（+）-rhodomyrtosone C（6）,rhotomentosones E-G（7-9）,（-）-rhodomyrtosone A（10）,（+）-rhodomyrtosone A（11）,rhodomyrtone B（12）,6,8-dihydroxy-2,2,4,4,9-pentamethyl-7-（3-methylbutanoyl）-4,9-di-hydro-1H-xanthene-1,3（2H）-dione（13）,rhodotomoside A（14）,2α,3β,19α,23-tetrahydr-oxyurs-12-en-28-oic acid（15）,asiatic acid（16）,actinidic acid（17）,28-norlupa-17（22）,20（28）-dien-3-ol,（3β）-（9CI）（18）,α-amyrin（19）,β-amyrin（20）,lupeol（21）,28-norlup-20（29）-en-3β-hydroxy-17β-hydroper-oxide（22）,28-norlup-20（29）-ene-3β,17β-diol（23）,betulinic acid（24）,19-norergosta-5,7,9,22-tetraene-3β-ol（25）,β-sitostenone（26）,p-hydroxy-phenylacetic acid methyl ester（27）,（-）-loliolide（28）,（7S,8R）-4,9,9’-trihydroxy-3,3’-dimethoxy-7,8-dihydrobenzofuran-1’-propylneolignan（29）,4-hydroxy-2,3-dimethyl-2-nonen-4-olide（30）,diisobutyl-phthalate（31）and dibutyl-phthalate（32）.Compound 12 had a good antibacterial ability against Staphylococcus aureus,Enterococcus faecium,with MIC values of 0.5μg/m L and 1.0μg/m L,respectively.Compound 12 is also active against Clostridium difficile and Propionibacterium acnes,with MIC values of 8.0μg/m L and 16.0μg/m L,respectively.All compounds tested were inactive against Escherichia coli.Compounds 7,8 and 14 have significant inhibitory activities ofα-glucosidase in vitro,with IC₅₀ in the range of 0.0680±0.0168～0.5040±0.1437 mg/m L.Conclusions:Compounds 1-32 were isolated from R.tomentosa.Among them,compounds 1-4,7-9,14 were new compounds.Moreover,compounds 1-4 and 7 were new skeletons compounds.In addition,compounds13,16,17,22,23,25 and 27-32 were isolated from R.tomentosa for the first time.Compound 12 had a good antibacterial ability against Staphylococcus aureus,Enterococcus faecium,Propionibacterium acnes and Clostridium difficile with MIC values of 0.5～16.0μg/m L,respectively.Compounds 7,8and 14 have significant inhibitory activities ofα-glucosidase in vitro,with IC₅₀in the range of 0.0680±0.0168～0.5040±0.1437 mg/m L.