Ruwei Wang

HPLC quantification of all five ginkgolic acid derivatives in Ginkgo biloba extracts using 13 : 0 ginkgolic acid as a single marker compound.

An HPLC quantification method for ginkgolic acid derivatives in Ginkgo biloba leaf extracts was developed. Using 13 : 0 ginkgolic acid as a marker compound, the relative correlation factors of the four other ginkgolic acid derivatives - namely, 15 : 0 ginkgolic acid, 15 : 1 ginkgolic acid, 17 : 1 ginkgolic acid, and 17 : 2 ginkgolic acid - to 13 : 0 ginkgolic acid were determined by HPLC and subsequently used for calculating their contents in ten hydro-ethanolic refined extract samples. In other words, the content of 13 : 0 ginkgolic acid in the extracts was determined using the isolated compound as an external standard. Subsequently the now known concentration of this compound functioned as an internal standard for the quantification of the other four ginkgolic acid derivatives via the described correlation factors. This HPLC method was validated by two independent control measurements, one with an external standard for every individual compound and one based on the present method with the single marker compound alone. The results did not differ significantly in any of the 10 tested extract samples. The protocol presented here thus not only uses the same reference substance for G. biloba extracts as the current Chinese Pharmacopoeia method but also incorporates the advantages of the current European Pharmacopoeia approach. It is simple, reproducible, and can be used to determine the total contents of ginkgolic acid derivatives in G. biloba leaf extracts.

Efficacy of a Novel Herbal Multicomponent Traditional Chinese Medicine Therapy Approach in Patients with Atopic Dermatitis

Background: In Western medicine, the application of topical steroids and oral antihistaminic or antiallergic agents is the main treatment option for atopic dermatitis (AD). However, instead of these therapies the disease may remain intractable in some patients, resulting in long-term exposure to these chemical agents and consequently leading to concerns about possible adverse drug reactions. Methods: In the present open-label clinical study, the efficacy and safety of a novel multi component TCM therapy approach for AD was investigated. Therefore, 94 patients received the formula I (10 crude drugs) orally, combined with both the lotion II (7 crude drugs), and the ointment III (8 crude drugs). Each crude drug was extracted with boiling water in a defined manner, concentrated, and reworked into the preparations. Standardized scores were used for evaluating the severities of AD (clinical severity 0-4) and pruritus (pruritus score 0-4). Results: Both scores had significantly improved at the end of a 12 month treatment (P<0.001). Eosinophil ratio and serum IgE levels, which were elevated in AD patients, were significantly reduced at the end of therapy (P<0.01). In 32 of 94 treated patients the condition markedly improved, in 59 cases AD improved, and in 3 patients there was a slight improvement with no case of ineffective treatment. There was no hint of renal or hepatic toxicity or any other adverse effects. Conclusion: The present study confirms that the 3 newly developed herbal TCM combination preparations are clinically efficacious on AD, accomplishing a significant reduction in both clinical and pruritus scores as well as in eosinophil ratios and serum IgE levels.

Antiproliferative Prenylated Xanthones from the Pericarps of Garcinia mangostana

Xanthones are a kind of natural products bearing a unique tricyclic aromatic system (C6–C3–C6) [1]. The structural diversities of these compounds arise mainly from the different substitutions of the A and B rings in the skeleton, with isoprene, methoxyl, and hydroxyl groups, being the most frequently occurring substituents. Accordingly, xanthones can be classied into several groups including simple oxygenated xanthones, prenylated xanthones, xanthone glycosides, and xanthonolignoids based on these substituents [2]. In recent years, xanthones have been identified as promising bioactive compounds with wide ranging and potentially usefull biological activities such as anticancer, anti-HIV, anti-inflammatory, antibacterial, and neurotrophic activities [3]. Garcinia mangostana is a tropical fruit native to Southeast Asia that has long been noted for its medicinal and health promoting properties [4]. Compared to the other species in the genus Garcinia, G. mangostana has captured the most attention due to its fruit, which was always referred to as the “queen of fruits.” The pericarps of G. mangostana fruit, a traditional medicine used for the treatment of infection, wounds, inflammation, and diarrhea in Southeast Asia, have recently been noted to be an abundant source of xanthones [1]. Herein, as part of our ongoing programs on the exploration of bioactive xanthones from Garcinia [5] and other related genus [6], eight prenylated xanthones were identified from the pericarps of G. mangostana and subjected to antiproliferative assay. G. mangostana fruits were purchased from the fruit market in Hangzhou and identified by Prof. Fa-Song Wang (Hubei University for Nationalities, P. R. China). A voucher specimen (No. ZJUTGM201009) was deposited with the Zhejiang University of Technology. The air-dried pericarps of G. mangostana fruits (4.5 kg) were crushed and extracted with ethanol (3 30 L). The extracts, after vacuum evaporation, was suspended in 2 L of distilled water and partitioned successively with petroleum ether (4 4 L) and CHCl3 (4 4 L) to give the petroleum ether-soluble and the CHCl3-soluble residues, respectively. The CHCl3-soluble residue (425 g) was subjected to column chromatography (CC) on silica gel eluting with petroleum ether– EtOAc (10:1 0:1) to furnish three fractions A–C. Fraction A was seprated by CC (MCI-CHP20P, CH3OH–H2O, 5:5 10:0) to afford two subfractions A1 and A2. Subfraction A1 (175.8 mg) was further purified by CC (HW-40, CH3OH) to give 2 (46.7 mg). Subfraction A2 (330.4 mg) was purified on CC (silica gel, petroleum ether–EtOAc, 15:1 10:1) to give 1 (16.2 mg), 5 (7.1 mg), and 8 (3 mg). Fraction B (2 g) was first separated by CC (silica gel, petroleum ether–acetone, 6:1) to give two subfractions B1 and B2, which were purified by CC (HW-40, CH3OH) to furnish 3 (25.7 mg) and 4 (30.0 mg), respectively. Fraction C was first recrystallized and filtered to produce 7 (ca. 100 g), and the filtrate was subjected to CC (silica gel, petroleum ether–acetone, 6:1) followed by CC (HW-40, CH3OH) to afford 6 (17.9 mg). The compounds were identified as 7-O-methylgarcinone E (1) [7], 8-desoxygartanin (2) [8], gartanin (3) [8], garcinone E (4) [9], 4 ,5 -dihydro-1,3,6-trihydroxy-6 ,6 -dimethyl-2,5-bis(3-methylbut-2-en-1-yl)pyrano[2 ,3 :7,8]xanthone (5) [10], 9-hydroxycalabaxanthone (6) [8, 11], -mangostin (7) [12], and tovophyllin A (8) [13] by spectroscopic methods, including NMR and mass spetrometry. These compounds have been previously isolated from the G. mangostana, but this is the first report of their co-occurrence at the same time in the plants.

A New Rumenic Acid Derivative from the Roots of Cudrania tricuspidata

A new rumenic acid derivative, threo-9,10-O-isopropylidene-13-hydroxy-(11E)-octadecenoic acid (1), and two known compounds, steppogenin (2) and oxyresveratrol (3), were isolated from the roots of Cudrania tricuspidata. The structure of the new compound was established by spectroscopic methods. All the compounds were evaluated for their cytotoxicity against three human tumor cell lines (HepG2, HCT-116, and SGC-7901). Unfortunately, none of them exhibited significant cytotoxicity at a concentration of 100 μM.

Lupane‐ and Friedelane‐Type Triterpenoids from Celastrus stylosus

Two new triterpenoids, 30‐hydroxylup‐20(29)‐ene 3β‐caffeate (1) and 24‐nor‐friedelan‐6α,10‐dihydroxy‐1,2‐dioxo‐4,7‐dien‐29‐oic acid (2), together with eight known compounds 3–10, were isolated from the roots of Celastrus stylosus. The structures of these compounds were elucidated on the basis of spectroscopic analyses. To the best of our knowledge, this represents the first study on the chemical constituents of C. stylosus. The antiproliferative activities of the triterpenoids against six human cancer cell lines (PANC‐1, A549, PC‐3, HepG2, SGC‐7901, and HCCLM3) were evaluated. Compounds 3, 4, and 10 exhibited comparable activities against PC‐3 and HCCLM3 cell lines as the positive control taxol.