Lifeng Han

A Review of Recent Research Progress on the Astragalus Genus

Astragalus L., is one of the largest genuses of flowering plants in the Leguminosae family. Roots of A. membranaceus Bge. var. mongholicus (Bge.) Hsiao, A. membranaceus (Fisch.) Bge. and its processed products are listed in the China Pharmacopeia for “qi deficiency” syndrome treatment. However, more and more researches on other species of Astragalus have been conducted recently. We summarize the recent researches of Astragalus species in phytochemistry and pharmacology. More than 200 constituents, including saponins and flavonoids, obtained from 46 species of Astragalus genus were collected for this article. In pharmacological studies, crude extracts of Astragalus, as well as isolated constituents showed anti-inflammatory, immunostimulant, antioxidative, anti-cancer, antidiabetic, cardioprotective, hepatoprotective, and antiviral activities. The goal of this article is to provide an overview of chemical and pharmacological studies on the Astragalus species over the last 10 years, which could be of value to new drug or food supplement research and development.

Rapid profiling and identification of triterpenoid saponins in crude extracts from Albizia julibrissin Durazz. by ultra high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry

Ultra high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC/ESI-Q-TOF-MS/MS) was applied to separate and identify triterpenoid saponins in crude extract from the stem bark of Albizia julibrissin Durazz. The molecular weights were determined by comparing quasi-molecular ions [M+NH(4)](+) in positive mode and [M-H](-) and [M-2H](2-) ions in negative mode. The MS/MS spectra of the [M-H](-) ions for saponins provided a wealth of structural information related to aglycone skeletons, sugar types and linked sequence. On the basis of the fragmentation behavior of known saponins isolated before, saponins from this plant were identified, even though references were not available. As a result, a total of twenty-eight saponins in the crude extract were identified, which all had a common basic skeleton of the triterpene oleanolic acid and eight of them were new compounds.

Structural Characterisation and Identification of Phenylethanoid Glycosides from Cistanches deserticola Y.C. Ma by UHPLC/ESI–QTOF–MS/MS

INTRODUCTION Phenylethanoid glycosides (PhGs) are the major active constituents of Cistanches deserticola Y.C. Ma. However, the isolation, purification and identification procedures of PhGs are difficult and time-consuming. OBJECTIVE To establish a rapid and sensitive ultrahigh-pressure liquid chromatography (UHPLC)/ESI (electrospray ion source)-quadrupole time of flight (QTOF)-MS/MS method that could be applied to rapidly profile and identify PhGs. METHODOLOGY Seven standard compounds were used for the investigation of the fragmentation pattern. Based on the UHPLC/ESI-QTOF-MS/MS method, the important structural information on the types of aglycone and saccharide sequences present should be obtained. RESULTS According to the HPLC retention behaviour, the proposed fragmentation pathways provided by high-resolution MS and MS/MS spectra and literature sources, a total of 13 PhGs in the crude extract of C. deserticola were identified or tentatively identified. CONCLUSION A rapid and accurate UHPLC/ESI-QTOF-MS/MS method was established for the identification of PhGs in the crude extract of C. deserticola. This method therefore can be used for rapid prediction of the chemical constituents and qualities of this plant.

Regulation effects of Crataegus pinnatifida leaf on glucose and lipids metabolism.

The leaf of Crataegus pinnatifida (Rosaceae) is commonly consumed either raw or cooked to improve digestion and promote blood circulation in China. To investigate the regulation effects of it on glucose and lipid metabolism, the flavonoids fraction was prepared and analyzed by HPLC and LC-MS. In vivo, at doses of 250 and 500 mg/kg, the flavonoids fraction showed inhibitory effects on TG and glucose absorption, accelerating effects on gastrointestinal transit but no effect on gastric emptying. In vitro, treatment of 3T3-L1 preadipocytes with 30 μg/mL flavonoids fraction significantly suppressed the accumulation of TG and free fatty acid. It also suppressed the gene expressions of C/EBPα, PPARγ, SREBP 1c, aP2 and adiponectin but did not affect that of leptin. C. pinnatifida leaf may be useful for type 2 diabetics and hyperlipidemics as a foodstuff.

Steroidal saponins from Tribulus terrestris.

Sixteen steroidal saponins, including seven previously unreported compounds, were isolated from Tribulus terrestris. The structures of the saponins were established using 1D and 2D NMR spectroscopy, mass spectrometry, and chemical methods. They were identified as: 26-O-β-d-glucopyranosyl-(25R)-furost-4-en-2α,3β,22α,26-tetrol-12-one (terrestrinin C), 26-O-β-d-glucopyranosyl-(25R)-furost-4-en-22α,26-diol-3,12-dione (terrestrinin D), 26-O-β-d-glucopyranosyl-(25S)-furost-4-en-22α,26-diol-3,6,12-trione (terrestrinin E), 26-O-β-d-glucopyranosyl-(25R)-5α-furostan-3β,22α,26-triol-12-one (terrestrinin F), 26-O-β-d-glucopyranosyl-(25R)-furost-4-en-12β,22α,26-triol-3-one (terrestrinin G), 26-O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl-(25R)-furost-4-en-22α,26-diol-3,12-dione (terrestrinin H), and 24-O-β-d-glucopyranosyl-(25S)-5α-spirostan-3β,24β-diol-12-one-3-O-β-d-glucopyranosyl-(1→4)-β-d-galactopyranoside (terrestrinin I). The isolated compounds were evaluated for their platelet aggregation activities. Three of the known saponins exhibited strong effects on the induction of platelet aggregation.

Bioactive Protopanaxatriol Type Saponins Isolated from the Roots of Panax Notoginseng (Burk.) F. H. Chen

Seven new protopanaxatriol type saponins, 20S-sanchirhinosides A1 (1), A2 (2), A3 (3), A4 (4), A5 (5), and A6 (6), and sanchirhinoside B (7) were obtained as minor constituents from the root extract of Panax notoginseng (Burkill, F. H. Chen), which showed protection effects against antimycin A induced mitochondrial oxidative stress. Their structures were elucidated by chemical and spectroscopic methods (IR, HRESI-TOF-MS, 1D and 2D NMR). Among them, compounds 4, 6 and 7 showed significant protective effects against antimycin A-induced L6 cell injury.

Qualitative and Quantitative Analysis of Eclipta prostrata L. by LC/MS

Eclipta prostrata L. is one of the Chinese medicinal tonics which are usually used for treating loose teeth, dizziness, tinnitus, hemoptysis, hematuria, and uterine bleeding. However, quality control of this herbal medicine has been not satisfactory. This study reported its qualitative and quantitative analyses based on LC/MS method. UHPLC-DAD-Q-TOF-MS fingerprinting and MS fragmentation cleavage pathway were investigated for qualitative analysis. Furthermore, a method for simultaneous quantitative determination of nine compounds, luteolin 7-O-β-D-glucopyranoside, ecliptasaponin C, luteolin, eclalbasaponin IV, apigenin, ecliptasaponin A, echinocystic acid 28-O-β-D-glucopyranoside, echinocystic acid, and 3-oxo-16α-hydroxy-olean-12-en-28-oic acid in E. prostrata, was established. The method was validated for samples of E. prostrata from different habitats. The results showed good linear correlation, precision, accuracy, and repeatability that could be used for contents determination of the nine compounds in E. prostrata from different habitats.

Rare Syringyl Acylated Flavonol Glycosides from the Aerial Parts of Leonurus japonicus Houtt.

Five new syringyl acylated flavonol glycosides, named leonurusoides A (1), B (2), C (3), D (4), and E (5), together with one known one 6 were obtained from the aerial parts of Leonurus japonicus. Their structures were elucidated by chemical and spectroscopic methods (UV, IR, HRESI-TOF-MS, 1D and 2D NMR). Compounds 1−6 showed triglyceride (TG) accumulation inhibitory effects in free fatty acid-induced HepG2 cells.

Eucommia ulmoides Bark Protects Against Renal Injury in Cadmium-Challenged Rats

Eucommia ulmoides Oliver is a perennial woody plant distributed widely in China. To characterize some major compounds in E. ulmoides bark extract, six compounds were identified via high-performance liquid chromatography qualitative analysis. E. ulmoides bark extract protects against cadmium-induced oxidative damage in rat kidneys. Two compounds of E. ulmoides bark extract, geniposide and genipin, which were identified both in serum and in kidney tissue, showed inhibitory effects on nitric oxide production. This study provides biological evidence supporting the usefulness of E. ulmoides bark against cadmium-induced toxic oxidative stress in rat kidney tissue.

Anti-inflammatory steroids from the rhizomes of Dioscorea septemloba Thunb.

Seven new steroid glycosides, dioscorosides A1 (1), A2 (2), B1 (3), B2 (4), C1 (5), C2 (6), and D (7), together with 22 known ones (8-29) were isolated from the rhizomes of Dioscorea septemloba, their structures were elucidated by chemical and spectroscopic methods. All isolates were evaluated for in vitro anti-inflammatory potential using LPS-stimulated RAW 264.7 murine macrophages. Among them, spirostane glycosides 18 and 21-24 exhibited significant inhibition of nitrite production. Moreover, the structure-activity relationship was summarized.