Hai-Sheng Chen

Alkaloids from Corydalis saxicola and Their Anti‐Hepatitis B Virus Activity

Eight protoberberine‐type alkaloids and two indole alkaloids were isolated from the MeOH extracts of the herb Corydalis saxicola Bunting (Papaveraceae). Their structures were identified as dehydrocavidine (1), dehydroapocavidine (2), dehydroisoapocavidine (3), berberine (4), dehydroisocorypalmine (5), coptisine (6), tetradehydroscoulerine (7), berbinium (8), 1‐formyl‐5‐methoxy‐6‐methylindoline (9), and 1‐formyl‐2‐hydroxy‐5‐methoxy‐6‐methylindoline (10). Compounds 3, 9, and 10 are new alkaloids. All compounds were tested for anti‐HBV activity against the 2.2.15 cell line in vitro. Dehydrocavidine (1), dehydroapocavidine (2), and dehydroisoapocavidine (3) exhibited inhibitory activity against HBsAg and HBeAg, but no cytotoxicity against the 2.2.15 cell line.

Two new triterpenoids from the roots of Actinidia chinensis

Two new triterpenoids (1, 2), together with one flavonoid glycoside and thirteen known triterpenoids were isolated from the roots of Actinidia chinensis Planch (Actinidiaceae). The structures of the new constituents were elucidated as 12α-chloro-2α, 3β, 13β, 23-tetrahydroxyolean-28-oic acid-13-lactone (1), 2α, 3α, 19α, 23, 24-pentahydroxyurs-12-en-28-oic acid (2). Structure elucidation was accomplished by 1D, 2D NMR spectra (HMQC, HMBC, (1)H-(1)H COSY, TOCSY, and NOESY) and mass spectrometry (ESIMS). Moreover, two known triterpenoids showed positive cytotoxic activity against LOVO and HepG2 cell lines.

A New Furostanol Saponin from Asparagus cochinchinensis

A new furostanol saponin, (25S)-26-O-β-d-glucopyranosyl-5β-furost-20(22)-en-3β, 15β,26-triol-3-O-[α-l-rhamnopyranosyl-(1–4)]-β-d-glucopyranoside, namely, aspacochioside D (1) were isolated from Asparagus cochinchinensis (Lour.) Merr, along with three known saponins, aspacochioside C (2), (25S)-5β-spirostan-3β-yl-O-[O-α-l-rhamnopyranosyl-(1–4)]-β-d-glucopyranoside (3), and pseudoprotoneodioscin (4). The structure of 1 was elucidated on the basis of chemical reactions and spectral analysis (IR, GC, ESI-MS, 1H-NMR, 13C-NMR, DEPT, HMBC, HMQC and NOESY). The antiproliferative effects of 1–4 were evaluated in a cytotoxicity assay against the human tumor cell line, A549. Compound 2 (Aspacochioside C) exhibited moderate cytotoxicity against A-549, with an IC50 value of 3.87 μg/mL.

A new indole alkaloid from Ervatamia yunnanensis

The stems of Ervatamia yunnanensis have afforded a new indole alkaloid, ervataine (1), whose structure was determined by spectroscopic analysis. Five known compounds, ibogaine (2) coronaridine (3), heyneanine (4), voacangine hydroxyindolenine (5) and coronaridine hydroxyindolenine (6), were also isolated.

Phenolic constituents of Canarium album

Canarium album (Lour.) Raeusch (Burseraceae) is widely distributed in southern China. Its fruits have been used as food in China. Also, the dried fruits of Canarium album (Lour.) Raeusch have been used in Chinese folk medicine for the treatment of angina, dysentery, snake bites, cough-hematemesis, falling sickness, enteritis, diarrhea, toxicosis from swellfish, and alcoholism [1]. Recently, phytochemical investigations found that this drug contained a number of phenolic compounds, such as gallic acid, brevifolin, scoparone, and hyperoside [2–4]. In the course of further studies, three monocyclic phenolic compounds: 3,4-dihydroxybenzoic acid ethyl ether (1) [5], 2-hydroxybenzoic acid (2) [5], ethyl gallate (3) [6]; two flavones: luteolin (4) [5], luteolin-7-O-D-glucoside (5) [7]; three flavonols: quercetin (6) [8], quercetin-3-O-D-glucoside (7) [9], kaempferol (8) [5], one flavanone: 7,8,3 ,4 -tetrahydroxyflavanone (9) [10], and one flavanonol: 3,5,7,3 -tetrahydroxy-4 -methoxyflavanonol (10) [11] have been isolated from the fruits. All the above compounds have not been reported before from this plant source. The EtOH extract was separated by repeated column chromatography using silica gel. The dried fruits (6 kg) were chopped and extracted with 80% EtOH three times under reflux and concentrated under vacuum to yield an EtOH extract (300 g). The concentrated solution was diluted with H2O and extracted successively with petroleum ether, EtOAc, and n-butanol. The EtOAc extract was separated by repeated column chromatography using silica gel and Sephadex LH-20 to afford compounds 1–10. All the phenolic compounds were identified by comparison of their 1H and 13C, DEPT NMR data. The 13C NMR data of the isolated phenolic compounds are shown in Tables 1 and 2.

A new quinazolinedione alkaloid from the fruits of Evodia officinalis

A new quinazolinedione alkaloid, wuchuyuamide IV (1) was isolated from the fruits of Evodia officinalis.1 showed moderate cytotoxicity against Hela and HT1080 cell lines.

Two new xanthones from Hypericum japonicum

Two new xanthones, 1,6-dihydroxyisojacereubin-5-O-β-D-glucoside (1) and 3,6,7-tri-hydroxy-1-methoxy-xanthone (2), were isolated from Hypericum japonicum. The structural elucidation of the isolated compounds were primarily based on HREIMS, EIMS, UV, IR, 1D-, and 2D-NMR analyses, including COSY, HMQC, HMBC, and NOESY correlations.

Chemical and biologically active constituents of Salsola collina

A new natural product (N-acetyltryptophan), together with 22 known constituents, including seven alkaloids, six flavonoids, six organic acids, and other compounds, were isolated from Salsola collina Pall. Their structures were elucidated on the basis of chemical reaction and spectral evidence. Among the isolated compounds, N-acetyltryptophan (8) showed moderate inhibition of a-amylase activity, and terrestric acid (9) showed positive antifungal activity.

Amides from Uvaria microcarpa

The dried stems of Uvaria microcarpa Champ. ex Benth. have significant antiplasmodia activity [1]. Previous studies showed that this plant contained a number of phenanthrene-carboxylic acid lactams [2]. Nine phenanthrene-carboxylic acid lactams and one amide were isolated from the EtOAc fraction of extracts of the stems of Uvaria microcarpa Champ. ex Benth., of which velutinam (1), enterocarpam II (2), goniopedaline (3), uvariadiamide (9), aristololactam B (10) were obtained from this plant for the first time. The stems of Uvaria microcarpa Champ. ex Benth. were collected from Hainan Province in June 2007 and identified by Mr. Zhu Ping, Hainan Tropical Botanic Garden of the Chinese Academy of Sciences. A voucher specimen has been deposited at the Department of Natural Medicinal Chemistry, School of Pharmacy, Second Military Medical University, Shanghai. The dried and chopped stems of Uvaria microcarpa Champ. ex Benth. (10 kg) were extracted with 95% EtOH (5 L 4) under reflux, then evaporated in vacuum. The residue (530 g) was further suspended in water and extracted successively with petroleum ether, EtOAc, and BuOH. The EtOAc extract was separated by repeated column chromatography using silica gel and Sephadex LH-20 to afford compounds 1–10. All compounds were identified by comparison of their 1H and 13C NMR data. The spectroscopic data of all compounds were in good agreement with the literature data [3–8]. The 1H NMR data are shown in Tables 1 and 2. The 13C NMR data are shown in Table 3. Uvariadiamide (9). Colorless needles (CH3OH). C18H20N2O2, 296. 1H NMR (DMSO-d6, , ppm, J/Hz): 1.57 (4H, br.t, J = 5.4, 2, 3-H), 3.27 (4H, br.t, J = 5.4, 1, 4-H), 7.42–7.83 (10H, m, Ar-H); 13C NMR (DMSO-d6): 168.1 (C=O), 26.7 (2, 3-C), 39.9 (1, 4-C), 127.1, 128.2, 131.0, 134.7 (Ar-C), 1H NMR and 13C NMR spectra have been published [8].

Constituents from the roots of Actinidia chinensis and their inhibitory activities toward cytochrome P450.

A newly discovered triterpenoid, (2α,3β)‐2,3,23‐trihydroxyurs‐13(18)‐en‐28‐oic acid (1), along with twelve known compounds (2 – 13), were isolated from the roots of Actinidia chinensis Planch (Actinidiaceae). Their chemical structures were determined by 1D‐ and 2D‐NMR spectra and mass spectrometry (MS). The crude extracts and six main constituents (8 – 13) were tested for cytochrome P450 (CYPs) enzyme inhibitory activity. The results showed that, except for compound 8, compounds 9 – 13 had different inhibitory effects on the cytochrome P450 (CYPs) enzyme, and compound 9 significantly inhibited the catalytic activities of CYP3A4 to < 10% of its control activities.