Pharmacokinetics and tissue distribution study of ginkgolide L in rats by ultra-high performance liquid chromatography coupled with tandem mass spectrometry.

An ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) approach was developed and validated for the determination of ginkgolide L (GL) in rat plasma and tissues using diazepam as internal standard (IS). Detection was performed on a triple quadrupole MS system using multiple reaction monitoring (MRM) mode in positive mode. Sample preparation was carried out through a liquid-liquid extraction with ethyl acetate.

Accurate analysis of ginkgolides and their hydrolyzed metabolites by analytical supercritical fluid chromatography hybrid tandem mass spectrometry.

Hydrolysis plays an important role in the metabolic transformations of lactones. Analysis of lactones and their hydrolyzed metabolites in biological samples is challenging, because unexpected hydrolysis or reversed dehydration may occur depending on the test environments. In this work, a supercritical fluid chromatography hybrid triple-quadrupole mass spectrometry (SFC-QQQ MS) method has been proposed for simultaneous analysis of ginkgolides and hydrolyzed metabolites.

Daturametelins H, I, and J: three new withanolide glycosides from Datura metel L.

Three new withanolide glycosides named daturametelins H-J (1-3), together with two known ones, daturataturin A (4) and 7,27-dihydroxy-1-oxowitha-2,5,24-trienolide (5), were isolated from the MeOH extract of the aerial parts of Datura metel L. (Solanaceae). Their structures were determined mainly by spectroscopic techniques including 2D-NMR (HMBC, HMQC, (1)H,(1)H-COSY, NOESY) and MS experiments.

Furostanoside from Asparagus filicinus.

A new furostanoside, named aspafilioside D (1), together with the five known compounds officinalisnin-II (2), Asp-IV' (3), (+)-4'-O-methyl-nyasol (4), (+)-nyasol (5) and tormentic acid (6), have been isolated from the roots of Asparagus filicinus. The structure of 1 has been elucidated on the basis of spectral data.

PTP1B inhibitors from Ardisia japonica.

In bioassay-directed isolation from the whole plant of Ardisia japonica, sixteen known compounds: chrysophanol (1), physcion (2), oleanolic acid (3), euscaphic acid (4), tormentic acid (5), quercetin (6), quercitrin (7), myricitrin (8), kaempferol 3-O-alpha-L-rhamnopyranoside (9), cyclamiretin A 3-O-alpha--rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->2)-[beta-D-glucopyranosyl(1-->4)]-alpha-L-arabinopyranoside (10), (7E)-9-hydroxymegastigma-4, 7-dien-3-on-9-O-beta-D-glucopyranoside (11), bergenin (12), norbergenin (13), rutin (14), kaempferol 3,7-O-alpha-L-dirhamnopyranoside (15), (-)-epigallacatechin 3-O-gallate (16) were obtained. Compounds 1-5, 9, 11 and 14-16 have not been reported previously from this plant. Among these isolates, 2, 3, 6 and 12 showed moderate bioactivity against PTP1B in vitro with IC50 values of 121.

[A new alkaloid from Opuntia vulgaris].

Aim: To study the chemical constituents of the stems of Opuntia vulgaris Mill(Cactaceae).

Methods: The compounds of Opuntia vulgaris were isolated by chromatography of Amberlite Dowex 50 and silica gel, and identified by means of UV, IR, MS, 1D and 2D NMR.

Results: Three compounds were isolated and identified as: opuntin B(I), 4-hydroxyproline(II) and tyrosine(III).

Guaiane-type sesquiterpenoids from Alisma orientalis.

Two guaiane-type sesquiterpenoids named orientalol E (1) and orientalol F (3) were isolated from the rhizome of Alisma orientalis (SAM) JUZEP together with two known guaiane-type sesquiterpenoids alismol (2) and alismoxide (4). Their relative stereostructures were elucidated by spectroscopic methods, whereas absolute stereostructures were determined on the basis of chemical correlation.

A flavonol tetraglycoside from Sophora japonica seeds.

A flavonol tetraglycoside, kaempferol 3-O-alpha-L-rhamnopyranosyl(1-->6)-beta-D-glucopyranosyl(1-->2)- beta-D-glucopyranoside-7-O-alpha-L rhamnopyranoside, together with nine known compounds were isolated from the seeds of Sophora japonica L. Their structures were elucidated on the basis of spectral and chemical evidence.

Isolation and identification of antioxidants from Sophora japonica.

A new flavonol triglycoside, kaempferol 3-O-alpha-L-rhamnopyranosyl-(1 --> 6)-beta-D-glucopyranosyl-(1 --> 2)-beta-D-glucopyranoside (1), as well as two known kaempferol 3-O-[alpha-L-rhamnopyranosyl-(1 --> 6)]-[beta-D-glucopyranosyl-(1 --> 2)]-beta-D-glucopyranoside (2) and kaempferol 3-O-beta-D-glucopyranosyl-(1 --> 2)-beta-D-glucopyranoside-7-O-alpha-L-rhamnopyranoside (3), were isolated from the n-BuOH extract of the pericarps of Sophora japonica by bioassay-guided fractionation. The structure of compound 1 was established by UV, IR, MS, and one- and two-dimensional NMR spectroscopy, including DEPT, NOESY, DQF-COSY, TOCSY, HMQC, and HMBC experiments. Compounds 1-3 showed antioxidative activity in DPPH and cytochrome-c assay using HL-60 cell system.

A new coumaronochromone from Sophora japonica.

A new coumaronochromone derivative, sophorophenolone (1), along with 13 known compounds, l-maackiain (2), medicagol (3), 7-O-methylpseudobaptigenin (4), pseudobaptigenin (5), 7,3'-di-O-methylorobol (6), genistein (7), prunetin (8), daidzein (9), formononetin (10), Di-O-methyldaidzein (11), quercetin (12), kaempferol (13) and isorhamnetin (14) were isolated from pericarps of Sophorajaponica L. The structure of compound 1 was established by UV, IR, MS, and one-dimensional and two-dimensional NMR spectroscopy, including DEPT, NOESY, 1H-1H COSY, HMQC, and HMBC experiments.