Phenolic Constituents, Antioxidant and Cytoprotective Activities, Enzyme Inhibition Abilities of Five Fractions from Vaccinium dunalianum Wight.

The bud of Vaccinium dunalianum Wight has been traditionally consumed as health herbal tea by "Yi" people in Yunnan Province, China, which was locally named "Que Zui tea". This paper studied the chemical constituents of five fractions from Vaccinium dunalianum, and their enzyme inhibitory effects of α-glucosidase and pancreatic lipase, antioxidant activity, and cytoprotective effects on H2O2-induced oxidative damage in HepG2 cells. The methanol extract of V. dunalianum was successively partitioned with petroleum ether (PF), chloroform (CF), ethyl acetate (EF), n-butanol (BF), and aqueous (WF) to obtain five fractions. The chemical profiling of the five fractions was analyzed by ultra-high-performance liquid chromatography coupled with a tandem mass spectrometry (UHPLC-MS/MS), and 18 compounds were tentatively identified. Compared to PF, CF, BF and WF, the EF revealed the highest total phenols (TPC) and total flavonoids (TFC), and displayed the strongest enzyme inhibition ability (α-glucosidase and pancreatic lipase) and antioxidant capacity (DPPH, ABTS and FRAP). Furthermore, these five fractions, especially EF, could effectively inhibit reactive oxygen species (ROS) production and cell apoptosis on H2O2-induced oxidative damage protection in HepG2 cells. This inhibitory effect might be caused by the up-regulation of intracellular antioxidant enzyme activity (CAT, SOD, and GSH). The flavonoids and phenolic acids of V. dunalianum might be the bioactive substances responsible for enzyme inhibitory, antioxidant, and cytoprotective activities.

[Studies on chemical constituents from roots of Mirabilis jalapa].

OBJECTIVE: To investigate the anti-HIV constituents from the root of Mirabilis jalapa. METHOD: The compounds were isolated by column chromatography on silica gel, Sephadex LH - 20, MCI-gel CHP-20P and RP-18. The structure were identified by means of NMR and MS analyses (1H-NMR, 13C-NMR, MS). RESULT: Eleven compounds were isolated and identified as astragaloside II (1), astragaloside II (2), astragaloside IV (3), astragaloside VI (4), flazin (5), 4'-hydroxy-2, 3-dihydroflavone 7-beta-D-glucopyranoside (6), gingerglycolipid A (7), 3, 4-dihydroxybenzaldehyd (8), p-hydroxybenzaldehyde (9), beta-sitosterol (10) and daucosterol (11). CONCLUSION: Compounds 1-9 were obtained from this genus for the first time.

Three new sesquiterpenoids from the aerial parts of Homalomena occulta.

Three new eudesmane-type sesquiterpenoids, compounds 1-3, and eight known constituents, including mucrolidin (4), 1beta,4beta,7alpha-trihydroxyeudesmane (5), 1beta,4beta,6beta,11-tetrahydroxyeudesmane (6), oplodiol (7), bullatantriol (8), acetylbullatantriol (9), homalomenol (10), and maristeminol (11), were isolated from the aerial parts of Homalomena occulta. Their structures were determined by interpretation of spectroscopic and mass-spectrometric data, and their antimicrobial activities toward six different bacterial strains were tested. Most of the compounds showed weak antibacterial activities in an agar-diffusion assay.

A new indolizinone from Polygonatum kingianum.

A new indolizinone, namely kinganone (1) together with 3-ethoxymethyl-5,6,7,8-tetrahydro-8-indolizinone (2) and isomucronulatol (3) were isolated from the rhizome of Polygonatum kingianum. Their structures were elucidated mainly on the basis of spectral data. Indolizinones 1 and 2 showed weak antibacterial and antifungal activities when compared to rifampicin and amphotericin, respectively, in the agar diffusion assay.