Li-Jie Zhang

Cytotoxic Hexacyclic Triterpene Acids from Euscaphis japonica.

Six hexacyclic triterpene acids (1-6), named euscaphic acids A-F, and eight known triterpene acid compounds (7-14) were isolated from an ethanolic extract of twigs of Euscaphis japonica. Compounds 8 and 10 were isolated for the first time from a natural source. Triterpenes 1-6 possess hexacyclic skeletons with a 13α,27-cyclopropane ring. Structural elucidation of compounds 1-6 was established by spectroscopic methods, especially 2D NMR techniques ((1)H-(1)H COSY, HMQC, HMBC, and NOESY). Compounds 3, 4, and 14 showed significant cytotoxicity against different cancer cell lines [IC50 = 2.54 (NCI-H460), 3.61 (MCF-7), and 3.27 μM (CEM) for 3, 4, and 14, respectively].

Antioxidant phenylpropanoid glycosides from Smilax bracteata.

From the ethanolic extract of Smilax bracteata, six phenylpropanoid glycosides, smilasides G-L (1-6), along with four known phenylpropanoid compounds, helonioside A, helonioside B, smilaside E, and (1-p-O-coumaroyl-6-O-feruroyl)-beta-d-fructofuranosyl-alpha-d-glucopyranoside, and fourteen known phenolic compounds were isolated. Their structures were elucidated on the basis of spectroscopic analyses. Moreover, 1-6 exhibited moderate scavenging activities against DPPH radicals.

Antiproliferative and hypoglycemic cucurbitane-type glycosides from the fruits of Momordica charantia.

This paper reports that bioassay-guided fractionations of EtOH extract of Momordica charantia fruits led to the isolation of 15 cucurbitane-type triterpene glycosides including 4 new compounds, kuguaosides A-D (1-4), along with 11 known ones, charantoside A (5), momordicosides I (6), F1 (7), F2 (8), K (9), L (10), and U (11), goyaglycosides-b (12) and -d (13), 7β,25-dihydroxycucurbita-5,23(E)-dien-19-al 3-O-β-d-allopyranoside (14), and 25-hydroxy-5β,19-epoxycucurbita-6,23-dien-19-on-3β-ol 3-O-β-d-glucopyranoside (15). Their structures were elucidated on the basis of spectroscopic analyses and chemical methods. This study also established the HPLC-ELSD fingerprinting profile of an antiproliferative fraction of which 11 main peaks were identified. Biological evaluation showed that several isolated cucurbitane-type triterpene glycosides had antiproliferative activities against MCF-7, WiDr, HEp-2, and Doay human tumor cell lines. In addition, compound 14 showed potent hypoglycemic activities by glucose uptake assay.

Administration of a Decoction of Sucrose- and Polysaccharide-Rich Radix Astragali (Huang Qi) Ameliorated Insulin Resistance and Fatty Liver but Affected Beta-Cell Function in Type 2 Diabetic Rats

The current investigation attempted to confirm the beneficial actions of a chemically characterized Radix Astragali decoction (AM-W) against type 2 diabetic (T2D) Sprague-Dawley (SD) rats. Using a case/control design, after 2 months of treatment with AM-W (500 mg/kg, daily i.p.) in T2D rats therapeutic outcomes were compared. Sucrose and Astragalus polysaccharides (ASPs) were shown to exist in nearly equal proportions in AM-W. Body weight loss, an improvement in insulin sensitivity, and an attenuation of fatty liver after AM-W administration in T2D rats were evident. Surprisingly, blood sugar, beta-cell function, and glucose tolerance in T2D rats did not improve with AM-W treatment. Further investigation indicated the deleterious effects of the addition of sucrose (100 and 500 μg/mL) and APSs (500 μg/mL) on glucose-stimulated insulin secretion and viability, respectively. In conclusion, a proper administration dosage and a reduction in the sucrose content are keys to maximizing the merits of this herb.

Conversion of Squid Pen to Homogentisic Acid via Paenibacillus sp. TKU036 and the Antioxidant and Anti-Inflammatory Activities of Homogentisic Acid

The culture supernatant of Paenibacillus sp. TKU036, a bacterium isolated from Taiwanese soils, showed high antioxidant activity (85%) when cultured in a squid pen powder (SPP)-containing medium at 37 °C for three days. Homogentisic acid (2,5-dihydroxyphenylacetic acid, HGA) was isolated and found to be the major antioxidant in the culture supernatant of the SPP-containing medium fermented by Paenibacillus sp. TKU036. Tryptophan was also present in the culture supernatant. The results of high-performance liquid chromatography (HPLC) fingerprinting showed that HGA and tryptophan were produced via fermentation but did not pre-exist in the unfermented SPP-containing medium. Neither HGA nor tryptophan was found in the culture supernatants obtained from the fermentation of nutrient broth or other chitinous material, i.e., medium containing shrimp head powder, by Paenibacillus sp. TKU036. The production of HGA via microorganisms has rarely been reported. In this study, we found that squid pen was a potential carbon and nitrogen source for Paenibacillus sp. Tryptophan (105 mg/L) and HGA (60 mg/L) were recovered from the culture supernatant. The isolated HGA was found to have higher antioxidant activity (IC50 = 6.9 μg/mL) than α-tocopherol (IC50 = 17.6 μg/mL). The anti-inflammatory activity of the isolated HGA (IC50 = 10.14 μg/mL) was lower than that of quercetin (IC50 = 1.14 μg/mL). As a result, squid pen, a fishery processing byproduct, is a valuable material for the production of tryptophan and the antioxidant and anti-inflammatory HGA via microbial conversion.

Antiinflammatory and Antioxidant Flavonoids and Phenols from Cardiospermum halicacabum (倒地鈴 Dào Dì Líng)

ABSTRACT Seventeen compounds, quercetin-3-O-α- l -rhamnoside (1), kaempferol-3-O-α- l -rhamnoside (2), apigenin-7-O-β- d -glucuronide (3), apigenin 7-O-β- d -glucuronide methyl ester (4), apigenin 7-O-β- d -glucuronide ethyl ester (5), chrysoeriol (6), apigenin (7), kaempferol (8), luteolin (9), quercetin (10), methyl 3,4-dihydroxybenzoate (11), p-coumaric acid (12), 4-hydroxybenzoic acid (13), hydroquinone (14), protocathehuic acid (15), gallic acid (16), and indole-3-carboxylic acid (17), were isolated from the ethanol extract of Taiwanese Cardiospermum halicabum. All chemical structures were determined by physical and extensive spectroscopic analyses such as 1H Nuclear Magnetic Resonance spectroscopy (NMR), 13C NMR, 1H-1H Correlation spectroscopy (1H-1H COSY), Heteronuclear Multiple Quantum Coherence spectroscopy (HMQC), Heteronuclear Multiple-bond Correlation spectroscopy (HMBC), and Nuclear Overhauser Effect spectroscopy (NOESY), as well as comparison with literature values. Furthermore, the High-Performance Liquid Chromatography-Photodiode Array Detector (HPLC-DAD) fingerprint profile was established for the determination of major constituents in the EtOAc extract and retention times of the isolated compounds. All isolated compounds were also evaluated for antiinflammatory and antioxidant activities.

5β,19-epoxycucurbitane triterpenoids from Momordica charantia and their anti-inflammatory and cytotoxic activity.

Five new 5β,19-epoxycucurbitane triterpenoids, taikugausins A-E (1-5), together with 5β,19-epoxy-25-methoxycucurbita-6,23-diene-3β,19-diol (6), have been isolated and characterized from the 70 % EtOH extract of the fresh fruits of Momordica charantia. The chemical structures of compounds 1-6 were elucidated on the basis of extensive spectroscopic analyses, especially 2D NMR (HMQC, HMBC, and NOESY) experiments and HRESIMS data. The relationship between NMR chemical shifts and the configuration of C-19 with an OMe group in 5β,19-epoxycucurbitane are described. Among them, compounds 3 and 4 exhibited remarkable anti-inflammatory activities by the inhibition of nitric oxide production at the concentration of 10 µg/mL. In addition, 3 and 4 also showed moderate cytotoxicity against WiDr, Hep G2, MCF-7, and HEp-2 human tumor cell lines.

Antioxidative Flavonol Glucuronides and Anti-HBsAg Flavonol from Rotala rotundifolia

Two new flavonol glucuronides, quercetin 3-O-β-D-2″-acetylglucuronide (1) and quercetin 3-O-β-D-2″-acetylglucuronide methyl ester (2), along with four known flavonoids (3-6) were isolated from the whole parts of Rotala rotundifolia. The structures of 1 and 2 were elucidated by application of various spectroscopic methods, including 1D and 2D NMR techniques. Biological evaluation showed that all of isolated flavonoid compounds have potent anti-oxidative activities by DPPH and superoxide anion methods, and kaempferol (3) and quercetin (4) exhibited significant anti-HBV activity assayed by anti-HBsAg production. The HPLC fingerprint with photodiode array detection (HPLC-DAD) for quality control of R. rotundifolia partitioned EtOAc layer was also established.

New Hirsutinolide-Type Sesquiterpenoids from Vernonia cinerea Inhibit Nitric Oxide Production in LPS-Stimulated RAW264.7 Cells

Phytochemical investigation of ethanol extracts from two Taiwanese collections of Vernonia cinerea resulted in the isolation of eighteen hirsutinolide-type sesquiterpenoids, including seven new ones designated as vernolides E - K (1: -7: ). All structures were determined by a combination of detailed spectroscopic analyses (NMR and MS) and comparison with reported data. In an in vitro anti-inflammatory assay, compounds 3, 7, 9, 11: , and 14: exhibited strong inhibitory activities toward NO production by LPS-induced RAW264.7 macrophages, with IC50 values of 1.18, 0.85, 0.66, 0.71 and 0.45 µM, respectively, without affecting cellular viability at 40 µM. Preliminary structure-activity relationships indicate that the ester groups at C-8 and C-13 may enhance inhibition of NO production.