Qizhi Wang

Triterpenoids from the Herbs of Salicornia bigelovii.

A new nortriterpene saponin, 3-O-β-d-glucuronopyranosyl-30-norolean-12,20(29)-dien-23-oxo-28-oic acid, namely bigelovii D (11), was isolated from the hydroalcoholic extract of herbs of Salicornia bigelovii along with 10 known saponins (1–10). Their chemical structures were identified on the basis of spectroscopic analyses including two-dimensional NMR and a comparison with literature data. Some of these compounds showed potent antifungal activities in vitro. Compounds 3, 4, 5, 6, 7, 10 and 11 demonstrated potent inhibitory activities against Colletotrichum gloeosporioides and compound 11 displayed broad-spectrum inhibitory activity against Alternaria alternata, A. solani, Botrytis cinerea, C. gloeosporioides, Fusarium graminearum, F. verticilloides, Thanatephorus cucumeris and Sclerotinia sclerotiorum, with EC50 values ranging from 13.6 to 36.3 μg/mL.

Cochliones A–D, four new tetrahydrochromanone derivatives from endophytic Cochliobolus sp.

Four new tetrahydrochromanone derivatives, cochliones A–D (1–4), along with three known metabolites, 4-hydroxybenzaldehyde (5), 4-hydroxy-3-(3-methylbut-2-enyl) benzoic acid (6), and 2,2-dimethyl-2H-chromene-6-carboxylic acid (7), were characterized from the culture of Cochliobolus sp. IFB-E039, a fungus that resides inside the healthy root of Cynodon dactylon (Gramineae). The structures of 1–4 were accommodated by their spectral data (UV, IR, CD, HR-ESI-MS, 1H and 13C NMR, 1H–1H COSY, HMQC, HMBC, and NOESY). The bioassay for the cytotoxic metabolite showed that cochlione C (3) inhibited human breast adenocarcinoma cell line (MCF-7) and human chronic myeloid leukemia cell line (K562) with IC50 values of 21.99 and 4.59 μg/ml, respectively.

A New Isoflavane from Suaeda glauca

A new isoflavane, 6,2′-dihydroxy-5,7-dimethoxyisoavanone (1), was isolated from the herb Suaeda glauca (Bunge) Bunge (Chenopodiaceae), in addition to six known compounds (2–7). The structures of the compounds were determined using chemical and spectral methods.

Isolation, identification and cytotoxicity of a new noroleanane-type triterpene saponin from Salicornia bigelovii Torr.

Salicornia bigelovii Torr. has been consumed not only as a popular kind of vegetable, but also as a medicinal plant to treat hypertension, cephalalgia, scurvy and cancer. The present study was designed to investigate its chemical components and cytotoxic activity. A new noroleanane-type triterpene saponin, bigelovii C (1), was separated and purified from Salicornia bigelovii Torr., along with four known triterpene saponins 2–5. The structure of bigelovii C was elucidated as 3-O-(6-O-butyl ester)-β-d-glucuropyranosyl-23-aldehyde-30-norolean-12, 20 (29)-dien-28-oic acid-28-O-β-d-glucopyranoside, according to various spectroscopic analysis and chemical characteristics. Besides Compounds 3 and 5, bigelovii C had potent cytotoxicity against three human cancer cell lines, MCF7 (breast cancer), Lovo (colon cancer) and LN229 (glioblastoma), especially MCF7. Bigelovii C inhibited the growth of MCF7 cells in dose- and time-dependent manners. Flow cytometry analysis revealed that the percentage of apoptotic cells significantly increased upon bigelovii C treatment. Rh123 staining assay indicated that bigelovii C reduced the mitochondrial membrane potential. The mechanism of cell death by bigelovii C may be attributed to the downregulation of Bcl-2 and upregulation of Bax, cleaved caspase-9, caspase-7 and PARP. These results suggested that bigelovii C may impart health benefits when consumed and should be regarded as a potential chemopreventative agent for cancer.

Crucial role of oxidative stress in bactericidal effect of parthenolide against Xanthomonas oryzae pv. oryzae : Role of oxidative stress in bactericidal effect of parthenolide

BACKGROUNDnXanthomonas oryzae pv. oryzae (Xoo) causes rice bacterial blight, which is one of the most devastating diseases on rice. Parthenolide (PTL) is a sesquiterpene lactone possessing multiple bioactivities. In the preliminary study, we found PTL can totally inhibit the growth of Xoo at 10 mg L-1 in vitro. In this study, we aim to further evaluate the anti-bacterial activity of PTL against Xoo and discern the role of oxidative stress in its bactericidal effect.nnnRESULTSnPTL was effective against Xoo both in vitro and in vivo. PTL induced reactive oxygen species (ROS) accumulation in Xoo, leading to cell death, while exogenous catalase can fully abolish its bactericidal effect. PTL sensitivity of catalase deletion mutants of Xoo increased significantly compared with that of wild-type Xoo strain. In addition, PTL treatment increased glutathione peroxidase activity and decreased glutathione (GSH) reductase activity in Xoo, but had no effect on its catalase and superoxide dismutase activities. Interestingly, PTL dramatically reduced the GSH level in Xoo, resulting in disturbed GSH/GSSG balance. Moreover, PTL rapidly reacted with GSH by a nucleophilic addition reaction.nnnCONCLUSIONnPTL is a promising lead compound for developing bactericide against Xoo. PTL rapidly reacts with GSH, resulting in disturbed GSH/GSSG balance in Xoo, which causes ROS accumulation, leading to cell death. Oxidative stress plays a critical role in the bactericidal effect of PTL against Xoo.

Induction of apoptosis by Bigelovii A through inhibition of NF‑κB activity

Bigelovii A is a 30-nortriterpenoid glycoside, isolated from Salicornia bigelovii Torr. Until now, the effect of Bigelovii A on breast cancer treatment was unknown. The present research indicated that Bigelovii A significantly inhibited the proliferation of human breast cancer cells (MCF-7, MDA-MB-231 and MDA-MB-468) in a concentration-dependent manner. It was particularly effective in MCF7 cells, with an IC50 value of 4.10±1.19 µM. The anti-proliferative effect of Bigelovii A was ascribed to the induction of apoptosis, which was characterized by chromatin condensation, externalization of phosphatidylserine on the plasma membrane, hypodiploid DNA, activation of caspases and poly (ADP-ribose) polymerase cleavage. Furthermore, Bigelovii A reduced B-cell lymphoma 2 (Bcl-2) and B-cell lymphoma-extra large (Bcl-xl) expression and caused disruption of mitochondrial membrane potential, which are indicative features of mitochondria-dependent apoptotic signals. It was also identified that Bigelovii A downregulated the constitutive activation of nuclear factor (NF)-κB, as indicated by the electrophoretic mobility gel shift assay and immunocytochemistry. Furthermore, Bigelovii A suppressed constitutive IκBα phosphorylation via inhibition of IκB kinase activity. In addition to the effects on Bcl-2 and Bcl-xl, Bigelovii A also downregulated the expression of the NF-κB-regulated gene products, Cyclin D1 and cyclooxygenase-2. This led to the induction of apoptosis and arrest of cells at the G1 phase of the cell cycle.

Three new quinazolines from Evodia rutaecarpa and their biological activity

In this research, we investigated the profile and bioactivities of quinazoline alkaloids, a class of natural products boasting multiple bioactivities, from the unripe fruit of Evodia rutaecarpa (Juss.) Benth. Three new quinazoline alkaloids, evodiamide A (1), evodiamide B (2), and evodiamide C (3), as well as eight known quinazolines, were isolated from the MeOH extract of E. rutaecarpa. The new compounds are rare quinazolinedione derivatives with linked heterocyclic nuclei. Among these quinazolines, rhetsinine (8) showed potential as a pesticide and exhibited excellent inhibition against Xanthomonas oryzae pv. oryzae, Xanthomonas oryzae pv. oryzicola, and Xanthomonas campestris pv. campestris, with respective EC50 values of 3.13, 14.32, and 32.72u202fnmol.

Flavonoids from Suaeda salsa II. Isolation, Structural Determination, and Antioxidant Activity

We have previously reported the structures of ten compounds (1–10) from the 95% ethanol extract of the leaves and stems of Suaeda salsa (L.) Pall. [1]. Through further study, we obtained ten flavones, luteolin (1), isorhamnetin (2), chrysoeriol (3), baicalein (4), quercetin (5), quercetin-3-O-D-glucopyranoside (6), isorhamnetin-3-O-D-glucopyranoside (7), tamarixetin-3-O-D-rutinoside (8), genkwanin-4 -O-D-rutinoside (9), and luteolin-3 -O-D-glucopyranoside (10). The structures of the flavones were established based on chemical and spectral (1H and 13CNMR) methods. The physical and spectral data of flavonoids 1–10 were in accordance with those reported in the literature. Luteolin (1). C15H10O6, yellow amorphous powder (EtOAc), mp 333–335 C. ESI-MS m/z 285 [M – H]– [2]. Isorhamnetin (2). C16H12O7, yellow amorphous powder (CHCl3–MeOH), mp 313–315 C. ESI-MS m/z 317 [M + H]+ [3]. Chrysoeriol (3). C16H12O6, yellow amorphous powder (EtOAc), mp 179–181 C. ESI-MS m/z 301 [M + H] + [4]. Baicalein (4). C15H10O5, yellow amorphous powder (EtOAc), mp 273–275 C. ESI-MS m/z 269 [M – H]– [5]. Quercetin (5). C15H10O7, yellow needle crystals (CHCl3–MeOH), mp 286–287 C. ESI-MS m/z 301 [M – H]– [6]. Quercetin-3-O-D-glucopyranoside (6). C21H20O12, yellow needle crystals (CHCl3–MeOH), mp 248–250 C. ESI-MS m/z 463 [M – H]– [7]. Isorhamnetin-3-O-D-glucopyranoside (7). C22H22O12, yellow amorphous powder (CHCl3–MeOH), mp 160–162 C. ESI-MS m/z 477 [M – H]– [6]. Tamarixetin-3-O-rutinoside (8). C28H32O16, yellow amorphous powder (MeOH), mp 286–288 C. ESI-MS m/z 623 [M – H]–. 1H NMR (300 MHz, DMSO-d6, , ppm, J/Hz): 12.57 (1H, br.s, 5-OH), 10.81 (1H, br.s, 7-OH), 9.75 (1H, br.s, 3 -OH), 6.22 (1H, d, J = 1.8, H-6), 6.43 (1H, d, J = 1.8, H-8), 7.50 (1H, d, J = 1.9, H-2 ), 7.03 (1H, d, J = 8.5, H-5 ), 7.71 (1H, dd, J = 1.9, 8.5, H-6 ), 3.85 (3H, s, 4 -OCH3), 5.37 (1H, d, J = 7.0, H-1 ), 4.40 (1H, br.s, H-1 ), 4.53–4.36 (6H, m, Glc-OH), 3.25–3.85 (10H, m, Glc protons), 0.99 (3H, d, J = 6.0, H-6 ). 13C NMR (75 MHz, DMSO-d6, , ppm): 156.4 (C-2), 133.0 (C-3), 177.3 (C-4), 161.1 (C-5), 98.7 (C-6), 164.1 (C-7), 93.8 (C-8), 156.5 (C-9), 104.0 (C-10), 121.1 (C-1 ), 113.3 (C-2 ), 146.9 (C-3 ), 149.4 (C-4 ), 115.2 (C-5 ), 122.3 (C-6 ), 55.7 (OCH3), 101.2 (C-1 ), 74.3 (C-2 ), 76.4 (C-3 ), 70.1 (C-4 ), 75.9 (C-5 ), 66.8 (C-6 ), 100.8 (C-1 ), 70.3 (C-2 ), 70.6 (C-3 ), 71.8 (C-4 ), 68.3 (C-5 ), 17.6 (C-6 ) [8]. Genkwanin-4 -O-D-rutinoside (9). C28H32O14, yellow amorphous powder (MeOH). ESI-MS m/z 591 [M – H] –. 1H NMR (300 MHz, DMSO-d6, , ppm, J/Hz): 12.89 (1H, br.s, 5-OH), 8.04 (2H, dd, J = 9.0, 2.0, H-6 , 2 ), 7.15 (2H, dd, J = 9.0, 2.0, H-3 , 5 ), 6.92 (1H, s, H-3), 6.80 (1H, d, J = 2.0, H-8), 6.47 (1H, d, J = 2.0, H-6), 5.07 (1H, d, J = 7.2, H-1 ), 4.58 (1H, br.s, H-1 ), 3.88 (3H, s, 7-OCH3), 4.39–4.16 (6H, m, Glc-OH), 3.20–3.60 (6H, m, H-2 –H-6 ), 3.20–3.60 (3H, m, H-2 –H-4 ), 2.51 (1H, d, J = 6.0, H-5 ), 1.10 (3H, d, J = 6.0, H-6 ). 13C NMR (75 MHz, DMSO-d6, , ppm): 162.4 (C-2), 103.0 (C-3), 181.9 (C-4), 161.1 (C-5), 99.3 (C-6), 164.3 (C-7), 94.4 (C-8), 156.9 (C-9), 103.2 (C-10), 121.0 (C-1 ), 128.5 (C-2 , 6 ), 116.0 (C-3 , 5 ), 161.3 (C-4 ), 55.9 (7-OCH3), 100.5 (C-1 ), 72.0 (C-2 ), 75.7 (C-3 ), 73.1 (C-4 ), 76.2 (C-5 ), 66.1 (C-6 ), 100.4 (C-1 ), 69.7 (C-2 ), 70.6 (C-3 ), 71.8 (C-4 ), 68.3 (C-5 ), 17.7 (C-6 ) [8].

Suaeglaucin A, a new coumaronochromone from Suaeda glauca

Abstract A new isoflavane, suaeglaucin A (1), which was isolated from the herb of Suaeda glauca (Bunge) Bunge, was elucidated as 5,6,8-trimethoxy-7- hydroxycoumaronochromone based on its MS and 1D and 2D NMR spectroscopic data. The structure of compound 1 was confirmed by X-ray crystallographic analysis. Five known compounds (2–6) were also isolated. All compounds were isolated for the first time from Chenopodiaceae. We found that compounds 2 and 4 possessed moderate antioxidant activity.

Phytochemical Constituents of Arenaria kansuensis

The whole plant of Arenaria kansuensis (Caryophyllaceae), a very important Chinese folk medicine, has been used to treat influenza, lung inflammation, jaundice, and rheumatism [1]. However, very few studies have been reported on the chemical constituents of the plant.Until now, the allocated substances previously isolated from A. kansuensis were mostly flavonoids, -carboline alkaloids, terpenoids, steroids, and phenylpropanoids [2]. As part of our continuing studies on bioactive compounds from A. kansuensis, we have carried out an investigation of the chemical constituents of the plant. Our phytochemical investigation led to the isolation of 10 compounds (1–10) from A. kansuensis, among which compounds 1, 6, 7, and 8 were isolated from a natural source for the first time; compounds 1, 2, 5, 6, 7, 8, and 10 were also isolated from A. kansuensis for the first time. The same for indole derivatives and phenethylamine derivatives, which were also isolated from A. kansuensis for the first time. The structures of 1–10 were all elucidated by spectroscopic methods, including 13C NMR, 1H NMR, and MS techniques. As far as we know, prior to this study, 13C NMR data of compounds 1, 7, and 8 have not been reported. This is the first time that the data mentioned have been confirmed. Another three compounds (3, 4, and 9) are known chemical constituents previously isolated from A. kansuensis. The isolated compounds were identified as 1-(9H-pyrido[3,4-b]indol-1-yl)ethane-1,2-diol (1) [3], cordysinin C (2) (light yellow powder, HR-ESI-MS m/z 213.1209 [M + H]+ (calcd for C13H13N2O, 213.1208) [4]), arenarine B (3) (pale yellow powder, HR-ESI-MS m/z 242.1102 [M]+ (calcd for C14H14N2O2, 242.1107) [5]), arenarine D (4) (light yellow powder, HR-ESI-MS m/z 226.0102 [M]+ (calcd for C13H10N2O2, 226.0107) [5]), -carboline-1-carboxylic acid (5) (yellow powder, HR-ESI-MS m/z 212.1102 [M]+ (calcd for C12H8N2O2, 212.1105) [6]), 1-(1-hydroxyethyl)pyrido[3,4-b]indole-3-carboxylate (6) (yellow powder, HR-ESI-MS m/z 270.1102 [M]+ (calcd for C15H14N2O3, 270.1101) [7]), N-hydroxyindole-3-carboxylic acid (7) [8], 4-hyroxy-3-methoxy-phenethylamine (8) [9], tricin (9) (yellow powder, HR-ESI-MS m/z 330.0702 [M]+ (calcd for C17H14O7, 330.0706) [10]), and tricin 7-O-Dglucopyranoside (10) (yellow powder, HR-ESI-MS m/z 492.0502 [M]+ (calcd for C23H24O12, 492.0501) [11]). Plant Material. The whole herbs of A. kansuensis were collected from Daban Mountain (101 24 2.8 E, 37 20 50.5 N, altitude 3990 m), Qinghai Province, China in September 2014. A voucher specimen (No. 0322810) has been deposited at the Key Laboratory of Tibetan Medicine Research, Chinese Academy Sciences, Xining, China. Extraction and Isolation. The dried and powdered whole plant (10 kg) was extracted with 83% aqueous ethanol (100 L 3) for 24 h to give a concentrated extract. The concentrated extract was suspended in water (3 L) and successively extracted with EtOAc (3 L 3) and n-BuOH (3 L 3) to yield concentrated extracts of the EtOAc (AKE, 865 g) and n-BuOH (AKB, 101 g) fractions. The concentrated EtOAc fraction (AKE, 865 g) was subjected to MCI column (6 90 cm) chromatography (CC) eluting with MeOH–H2O (9:1); the eluent was monitored by thin-layer chromatography (TLC) until nothing appeared on the TLC. The concentrated fraction was successively subjected to silica gel (SiO2) column (8 150 cm) chromatography (CC) eluting with CH2Cl2–MeOH–H2O (7:3:0.5); the eluent was monitored by thin-layer chromatography (TLC) until nothing appeared on the TLC. The concentrated fraction was successively prepared using semi-preparation dynamic axial compression columns (DAC-HB50, RP-C18, 5 65 cm, elueting parameter: MeOH–H2O, 30–70% gradient elution for