RESUMEN
Nineteen compounds were isolated from the water-soluble extract of the dry roots of Paeonia lactiflora by using various chromatographic techniques. Their structures were identified by MS, NMR and other spectroscopic analysis as paeoniflorin(1), 4--ethylpaeoniflorin(2), 2'--benzoylpaeoniflorin(3), benzoylpaeoniflorin(4), 4"-hydroxy-benzoyloxypaeoniflorin(5), moudanpioside C(6), 6'--benzoyl-4"-hydroxy-3"-methoxy-paeoniflorin(7), paeoniflorin B(8), 6--benzoylalbiflorin(9), secoisolariciresinol (10), (+)-lyoniresinol(11), dihyrodehydrodiconiferyl alcohol(12), ()-threo-7,9,9'-trihydroxy-3,3'-dimethoxy-8--4'-neolignan(13), (+)-neo-olivil (14), [()-5-methyl-2,3-dihydro-1-benzofuran-3-yl]methanol(15), 5-hydroxy--hydroxymethyl-6-methyl-2,3-dihydrobenzofuran(16), (+)-()-2-hydroxy-1-(4-methoxyphenyl)-1-propan-1-one(17), (+)-(2)-1-(4-hydroxy-3-methoxyphenyl)-2-propanol(18), (+)-()-()-4-hydroxy-2-nonenoic acid(19). Compounds 15 and 18 are new natural products, while compounds 10, 11, 13, 14, 17 and 19 are isolated from the genus Paeonia for the first time.
RESUMEN
Dihydrochelerythrine was isolated from the ethanol extract of Corydalis yanhusuo by chromatographic and recrystallization techniques. To our knowledge, this is the first report that dihydrochelerythrine was found to be unstable. The NMR, HPLC, and LC-MS were applied to monitor the structural conversion process of dihydrochelerythrine. The results showed that when dissolved in polar deuteration solvent (e.g., DMSO-₆ & MeOD), dihydrochelerythrine is directly converted to chelerythrine gradually. However, if used non-polar reagent (e.g.,CD₂Cl₂), the sample of dihydrochelerythrine undergoes the formation of pseudobase, chelerythrine, and bimolecular ether then followed by oxidation to oxychelerythrine as the major final product. Which leads to this phenomenon maybe is that the C-6 in dihydrochelerythrine is highly reactive to nucleophiles, and is easily converted to different derivatives in different solvents attributed to the solvent effect. This finding will contribute to the extraction and isolation, bioactivity screening, and quality evaluation of medicinal materials containing dihydrochelerythrine and other similar derivatives.
RESUMEN
A new styrene dimer derivative has been isolated from the branch of Litsea greenmaniana by column chromatography over silica gel and Sephadex LH-20, as well as semi-preparative HPLC. Its structure was identified by spectroscopic data analysis (MS, UV, IR, 1D and 2D NMR) as (E)-2,4-bis(p-hydroxyphenyl)-2-butenol, named as listeanol. At a concentration of 1×10-5 mol•L⁻¹, compound 1 was inactive in the assays, including cytotoxicity against human tumor cell lines (HCT-8, Bel-7402, BGC-823, A549 and A2780), antioxidant activity in Fe²⁺-cystine-induced rat liver microsomal lipid peroxidation, neuroprotective activity against serum deprivation or glutamate induced neurotoxicity in cultures of PC12 cells, and the inhibitory activity against protein tyrosine phosphatase 1B (PTP1B).
RESUMEN
A new phomapyrone derivative (1), and 9 known compounds were isolated from the ethyl acetate fraction of solid fermentation of Fusarium redolens, the endophytic fungus from Edgeworthia chrysantha, by using various isolation techniques such as Sephadex LH-20, MCI GEL and Semi pre-HPLC, etc. Their structures were identified by spectroscopic analysis, including MS, UV, CD, specific rotation, IR, 1D and 2D NMR, as (+)-7S-4-deoxy-9-hydroxyphomapyrone C (1), uracil (2), uridine (3), 2'-deoxyuridine (4), adenosine (5), 2'-deoxyadenosine (6), cordysinin B (7), ergosterol (8), ergosta-5α, 8β-epidioxy-6, 22-dien-3β-ol (9), and (22E, 24S)-3α-hydroxy-24-methylcholesta-5, 8, 22-trien-7-one (10).