Quick and selective extraction of Z-ligustilide from Angelica sinensis using magnetic multiwalled carbon nanotubes.

A facile and highly efficient magnetic solid-phase extraction method has been developed for Z-ligustilide, the major therapeutic agent in Angelica sinensis. The solid-phase adsorbent material used was prepared by conjugating carbon nanotubes with magnetic Fe3 O4 nanoparticles via a hydrothermal reaction. The magnetic material showed a high affinity toward Z-ligustilide due to the π-π stacking interaction between the carbon nanotubes and Z-ligustilide, allowing a quick and selective exaction of Z-ligustilide from complex sample matrices. Factors influencing the magnetic solid-phase extraction such as the amount of the added adsorbent, adsorption and desorption time, and desorption solvent, were investigated. Due to its high extraction efficiency, this method was proved highly useful for sample cleanup/enrichment in quantitative high-performance liquid chromatography analysis. The proposed method had a linear calibration curve (R(2) = 0.9983) over the concentration between 4 ng/mL and 200 µg/mL Z-ligustilide. The accuracy of the method was determined by the recovery, which was from 92.07 to 104.02%, with the relative standard deviations >4.51%.

Metabolic study of Angelica dahurica extracts using a reusable liver microsomal nanobioreactor by liquid chromatography-mass spectrometry.

Highly active and recoverable nanobioreactors prepared by immobilizing rat liver microsomes on magnetic nanoparticles (LMMNPs) were utilized in metabolic study of Angelica dahurica extracts. Five metabolites were detected in the incubation solution of the extracts and LMMNPs, which were identified by means of HPLC-MS as trans-imperatorin hydroxylate (M1), cis-imperatorin hydroxylate (M2), imperatorin epoxide (M3), trans-isoimperatorin hydroxylate (M1') and cis-isoimperatorin hydroxylate (speculated M2'). Compared with the metabolisms of imperatorin and isoimperatorin, it was found that the five metabolites were all transformed from these two major compounds present in the plant. Since no study on isoimperatorin metabolism by liver microsomal enzyme system has been reported so far, its metabolites (M1' and M3') were isolated by preparative HPLC for structure elucidation by (1) H-NMR and MS(2) analysis. M3' was identified as isoimperatorin epoxide, which is a new compound as far as its chemical structure is concerned. However, interestingly, M3' was not detected in the metabolism of the whole plant extract. In addition, a study with known chemical inhibitors on individual isozymes of the microsomal enzyme family revealed that CYP1A2 is involved in metabolisms of both isoimperatorin and imperatorin, and CYP3A4 only in that of isoimperatorin.

Selective extraction of berberine from Cortex Phellodendri using polydopamine-coated magnetic nanoparticles.

A new extraction agent featuring dopamine self-polymerized on magnetic Fe3 O4 nanoparticles has been successfully synthesized and evaluated for the SPE of berberine from the extract of the traditional Chinese medicinal plant, Cortex Phellodendri. The nanoparticles prepared possessed a core-shell structure and showed super-paramagnetism. It was found that these polydopamine-coated nanoparticles exhibited strong and selective adsorption for berberine. Among the chemical components present in C. Phellodendri, only berberine was adsorbed by the nanoparticles and extracted by a following SPE procedure. Various conditions such as the amount of polydopamine-coated nanoparticles, desorption solvent, desorption time and equilibrium time were optimized for the SPE of berberine. The purity of berberine extracted from C. Phellodendri was determined to be as high as 91.3% compared with that of 9.5% in the extract. The established SPE protocol combined advantages of highly selective enrichment with easy magnetic separation, and proved to be a facile efficient procedure for the isolation of berberine. Further, the prepared polydopamine-coated magnetic nanoparticles could be reused for multiple times, reducing operational cost. The applicability and reliability of the developed SPE method were demonstrated by isolating berberine from three different C. Phellodendri extracts. Recoveries of 85.4-111.2% were obtained with relative standard deviations ranging from 0.27-2.05%.

Chemical constituents from the aerial parts of Artemisia minor.

Four new compounds including three bicoumarins, arteminorins A-C (1-3), and one neolignan, arteminorin D (4), together with 31 known ones were isolated from the aerial parts of Artemisia minor. Their structures were established on the basis of spectroscopic data and comparison with those of the related known compounds. Ethyl caffeate (27) showed in vitro cytotoxicity against the HepG2 cancer cell line. Arteminorin C (3) and luteolin (19) showed inhibitory activity on xanthine oxidase (XOD), and caffeic acid (28) exhibited inhibitory activity on protein tyrosine phosphatase 1B (PTP1B).

[Chemical constituents of aerial part of Acalypha australis].

OBJECTIVE: To study the chemical constituents in the aerial part of Acalypha australis. METHOD: The aerial part of Acalypha australis were extracted with EtOH at room temperature. The compounds were separated by various kinds of chromatographic methods and their structures were identified on the basis of spectroscopic techniques. RESULT: Eleven compounds have been isolated and identified: emodin (1), beta-sitosterol (2), loliolide (3), 2,6-dimethoxy-1,4-benzoquinone (4), nicotinic acid (5), protocatechuic acid (6), daucosterol (7), gallic acid (8), rutin (9), succinic acid (10), brevifolin (11). CONCLUSION: Compounds 1, 3-5, 10 and 11 were obtained from A. australis for the first time.

Minor iridoids from the roots of Valeriana wallichii.

Four new iridoids, valeriotetrates B and C (1 and 2), 8-methylvalepotriate (3), and 1,5-dihydroxy-3,8-epoxyvalechlorine A (4), together with three known iridoids, were isolated from the roots of Valeriana wallichii. The structures of the new compounds were elucidated by analysis of 1D and 2D NMR and HRESIMS data. Compound 4 is an unusual iridoid bearing a C-10 chloro group and an oxo bridge connecting C-3 and C-8, resulting in a rigid skeleton.

Negative electrospray ionization tandem mass spectrometric investigation of ent-kaurane diterpenoids from the genus Isodon.

ent-Kaurane diterpenoids are a class of natural compounds isolated from genus Isodon, which have been found to have important bioactivities. Negative electrospray ionization tandem mass spectrometry ((-)ESI-MS(n)) was used to investigate the fragmentation pattern of C-20-nonoxygenated ent-kauranes and two subtypes of C-20-oxygenated ent-kauranes by using an ion trap instrument and accurate mass measurement on an ESI-Q-time-of-flight (TOF) mass spectrometer. The analysis revealed that loss of CH(2)O or CO(2) is the predominant process for 7, 20-epoxy and 7, 20 : 14, 20-diepoxy subgroup of C-20-oxygenated ent-kauranes. In addition, compounds of C-20-nonoxygenated ent-kauranes with a conserved core structure but different substituent groups, such as a hydroxyl, aldehyde, carboxyl, and acetyl moiety, resulted in diagnostic product ions through losses of H(2)O, CO, CO(2), and AcOH, respectively. This work clearly demonstrates the utility of tandem mass spectrometry for studies on the rationalization of the diagnostic fragmentation of a series of compounds from two main types of the ent-kaurane diterpenoids.

[Studies on chemical constituents of Eriophyton wallichii].

OBJECTIVE: To study the chemical constituents of Eriophyton wallichii. METHOD: The constituents were isolated and purified by silica gel column and Sephadex LH-20 chromatography. Their structures are elucidated by physicochemical properties and spectral analysis. RESULT: Seven compounds were obtained and identified as beta-sitosterol (1), marrubiin (2), ursolic acid (3), cimigoside (4), 5-deoxyantirrhinoside (5), 8-epiloganic acid (6) and apigenin 7-(6"-p-coumaroyl) glucoside (7). CONCLUSION: Compounds 1-7 were isolated from this plant for the first time.

Multistage electrospray ionization mass spectrometric analyses of sulfur-containing iridoid glucosides in Paederia scandens.

Paederia scandens is a traditional Chinese herbal medicine that possesses important bioactive sulfur-containing iridoid glucosides. This study reports the investigation of the fragmentation behavior of four sulfur-containing iridoid glucosides isolated from P. scandens by ion trap electrospray ionization tandem mass spectrometry (ESI-MSn). Both multistage electrospray ionization (ESI-MSn) experiments in an ion trap instrument and high-resolution and accurate mass measurement in an ESI-Q-TOF mass spectrometer in positive mode were used to elucidate the main fragmentation pathways of these compounds. These experiments yielded essentially the same product ions in both ion trap and Q-TOF instruments, and their fragmentation patterns were found useful for their characterization, which were applied to elucidate a trace compound in the extracts of P. scandens by on-line LC/ESI-MSn. Major and diagnostic product ions have been identified and their origins are proposed.

ent-Abietane diterpenoids from Isodon rubescens var. rubescens.

ent-Abietane diterpenoids, hebeiabinins A-F (1-5), together with seven known diterpenoids were isolated from leaves of Isodon rubescens var. rubescens. The structures of 1-5 were established on the basis of spectroscopic analyses, including application of 2D NMR spectroscopic techniques. The diterpenoids isolated were evaluated for the cytotoxicity against A549, HT-29, and K562 tumor cells. Compound 5 was the most active with IC(50) value of 0.91 microM against A549 cells.

[Studies on chemical constituents of Paederia scandense].

OBJECTIVE: To study the chemical constituents of Paederia scandense. METHOD: The constituents were isolated and purified by silica gel and Sephadex LH - 20 column chromatography. Their structures were elucidated by physicochemical properties and spectral analysis. RESULT: 20 compounds were obtained and identified as rubiadin-1-methylether (1), diadzein (2), cleomiscosin B (3), cleomiscosin D (4), isolariciresinol (5), linarin (6), isoscopoletin (7), caffic acid (8), coumarinic acid (9), p-hydroxyl-benzoic acid (10), oleanolic acid (11), ursolic acid (12), beta-sitosterol (13), daucosterol (14), paederoside (15), paederosidic acid (16), paederosidic acid methyl ester (17), saprosmoside E (18), paederoscandoside (19), caffeic acid 4-O-beta-D-glucopyranoside (20). CONCLUSION: Compounds 1-10, and 20 were isolated from this plant for the first time.

A new dihydroisocoumarin from the rhizomes of Notopterygium forbesii.

A new dihydroisocoumarin, 6-methoxyhydrangenol (1) as well as eleven known compounds were isolated from a traditional Chinese medicine, the rhizomes of Notopterygium forbesii Boiss. The structure of 1 was elucidated by spectroscopic methods.

Two new phthalides from Ligusticum chuanxiong.

Two new phthalide dimers, namely chuanxiongnolide A (1) and chuanxiongnolide B (2), along with eleven known phthalides and derivatives ( 3 - 13), were isolated from the roots of Ligusticum chuanxiong Hort. (Umbelliferae). The chemical structures of the new compounds were established by HR-ESI-MS, 1D- and 2D-NMR spectroscopic analysis, whilst the relative stereochemistry of 1 was confirmed by X-ray crystallographic data.

Three new diterpene alkaloids from the roots of Aconitum nagarum var. lasiandrum.

Three new diterpene alkaloids, 16,17-dihydro-12 beta,16 beta-epoxynapelline (1), N-deethyl- N-methyl-12-epi-napelline (2) and 11- epi-16 alpha,17-dihydroxylepenine (3), along with twenty-six known alkaloids (4 - 29) were isolated from the roots of Aconitum nagarum var. lasiandrum. The chemical structures of the new compounds were established by HR-MS as well as 1D- and 2D-NMR spectroscopic analysis. The absolute stereochemistry of 1 was confirmed by X-ray crystallography.

ent-Kaurane Diterpenoids from Isodon albopilosus.

Nine new diterpenoids, albopilosins B-J (1-9), together with six known analogues, albopilosin A (10), macrocalyxin C (11), rabdokunmin C (12), excisanin (13), amethystonoic acid (14), and coetsanoic acid (15), were isolated from the aerial parts of Isodon albopilosus. The structures of 1-9 were established using spectroscopic methods including extensive 1D and 2D NMR analysis. The diterpenoids isolated were evaluated for their inhibitory activities against HepG2 (hepatoma) cells. Compounds 7 and 13 were the most active, with both having IC(50) values of <15 microM.

Chemical constituents from Cimicifuga foetida.

From the rhizoma of Cimicifuga foetida L. (Ranunculaceae) a new chromone, 6'-hydroxylangelicain (18), has been isolated together with 20 known compounds. The structure of 18 has been elucidated on the basis of spectroscopic and chemical evidence.

Triterpenoid saponins from Anemone begoniifolia.

A new triterpenoid saponin, begoniifolide D (1), along with eight known ones (2-9) has been isolated from the methanol extracts of Anemone begoniifolia Lévl. et Vant. Their structures have been elucidated by spectroscopic and chemical methods.

[Chemical constituents of Hyperricum monogynum].

OBJECTIVE: To investigate the chemical constituents from the aerial parts of Hyperricum monogynum. METHOD: Compounds were isolated by various column chromatography and identified by spectral analysis. RESULT: Ten compounds were isolated and identified as quercetin, quercitrin, hyperoside, rutin, (-)-epicatechin, 3,5-dihydroxy-1-methoxy-xanthone, 3,4-O-isopropylidenyl shikimic acid, shikimic acid, daucosterol, and oleanoic acid. CONCLUSION: All compounds were isolated from this plant for the first time.

[Chemical constituents of Notoseris rhombiformis].

AIM: To investigate the chemical constituents from the whole plant of the endemic plant Notoseris rhombiformis Shih. METHODS: Column chromatography was used for separation and purification, while spectral analysis was used for structure elucidation. RESULTS: Eight compounds were isolated from the whole plant of this Chinese endemic plant and their structures were elucidated as notoserolide A (1), notoserolide D (2), austricin (3), jacquilenin (4), 3 beta, 14-dihydroxy-11 beta, 13-dihydrocostunolide (5), p-hydroxyphenylacetic acid (6), luteolin-7-O-beta-D-glucopyranoside (7) and daucosterol (8), respectively. CONCLUSION: All compounds were isolated from this plant for the first time. Among them, 2 is a new compound.