ABSTRACT
Pavetta crassipes leaf (Fam. Rubiaceae) is used as part of a combination herbal remedy for the treatment of tuberculosis (TB) and other respiratory infections in Nigerian ethno medicine. However, little scientific data is available to support the use in ethnomedical therapy so the objective of the study was to assess the anti-tubercular property and to identify the bioactive components. The dried powdered leaf was sequentially extracted with solvents to obtain hexane, dichloromethane, methanol and water extracts. Following which, the extracts were then screened against Mycobacterium aurum, a rapidly growing saprophytic mycobacterium species for activity. The methanol extract exhibited inhibitory activity at an MIC value of 250 µg/mL against M. aurum and two known polyphenolic compounds were isolated as 5-O-caffeoylquinic acid methyl ester and quercetin-3-rutinoside (rutin). Reversed phase semi-preparative HPLC, mass spectrometry and 1H and 13C NMR techniques were utilized in isolating and characterizing the two components. The assignments of the structures were consistent with data from the literature. The study has shown that the methanol extract has some activity and hyphenation of LC-MS can be used for the isolation of polyphenols from the methanol fraction without a rigorous purification process.
ABSTRACT
Objective:To simultaneously separate 5 phenylpropanoids from Cinnamomum cassia by semi-preparative HPLC, and explore their immunosuppressive activity. Methods:After extracted by ethanol, the ethyl acetate part of Cinnamomum cassia was isola-ted by semi-preparative HPLC. The separation was conducted on an Ultimate XB-C18 (250 mm × 10 mm, 5μm) semi-preparative chro-matographic column and the mobile phase was acetonitrile-water with gradient elution. The detection wavelength was 330 nm, and the flow rate was 2. 5 ml·min-1 . The sample volume was 0. 3 ml. MS and NMR spectroscopic analysis were used to determine the config-urations. A CCK-8 method was used to detect the immunosuppressive activity of phenylpropanoids. Results: Totally 5 phenylpro-panoids were separated from Cinnamomum cassia by the semi-preparative HPLC, and identified as erythro-guaiacylglycerol, (7R,8S)-syringoylglycerol, (7S,8S)-syringoylglycerol, 3-methoxyphenyl-acrylaldehyde and O-methoxy cinnamaldehyde. The inhibitory rates of T cells and B cells of the compound 3 was more than 20% at the concentration of 800μmol·L-1 . Conclusion:The method is conven-ient with good separation effect, which can simultaneously separate 5 phenylpropanoids from Cinnamomum cassia, and among them, the compound 3 shows immunosuppressive effect to some extent.
ABSTRACT
Objective: To study the chemical constituents from Peperomia dindygulensis. Methods: The chemical constituents in chloroform fraction of ethanol extract from P. dindygulensis were isolated and purified by column chromatography over silica gel column, preparative TLC, and semi-preparative HPLC. Their chemical structures were elucidated on the basis of physicochemical and spectral data. Results: Two new polyketides were isolated from the chloroform extracting fraction of P. dindygulensis and identified as (4S)-1,4-dihydroxy-2-(1′, 13′-diketone-octadec-14′E-ene)-1-cyclohexen-3-one (1) and (4S)-1,4-dihydroxy-2-(1′,14′-diketone-octadec-12′E-ene) -1-cyclohexen-3-one (2). Conclusion: Compounds 1 and 2 are new compounds and named as peperomadinone A and peperomadinone B.