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991.
Anti‐HSV‐1 and HSV‐2 Flavonoids and a New Kaempferol Triglycoside from the Medicinal Plant Kalanchoe daigremontiana 下载免费PDF全文
Fernanda Gouvêa Gomes Ürményi Georgia do Nascimento Saraiva Livia Marques Casanova Amanda dos Santos Matos Luiza Maria de Magalhães Camargo Maria Teresa Villela Romanos Sônia Soares Costa 《化学与生物多样性》2016,13(12):1707-1714
Kalanchoe daigremontiana (Crassulaceae) is a medicinal plant native to Madagascar. The aim of this study was to investigate the flavonoid content of an aqueous leaf extract from K. daigremontiana (Kd), and assess its antiherpetic potential. The major flavonoid, kaempferol 3‐O‐β‐d ‐xylopyranosyl‐(1 → 2)‐α‐l ‐rhamnopyranoside ( 1 ), was isolated from the AcOEt fraction (Kd‐AC). The BuOH‐soluble fraction afforded quercetin 3‐O‐β‐d ‐xylopyranosyl‐(1 → 2)‐α‐l ‐rhamnopyranoside ( 2 ) and the new kaempferol 3‐O‐β‐d ‐xylopyranosyl‐(1 → 2)‐α‐l ‐rhamnopyranoside‐7‐O‐β‐d ‐glucopyranoside ( 3 ), named daigremontrioside. The crude extract, Kd‐AC fraction, flavonoids 1 and 2 were evaluated using acyclovir‐sensitive strains of HSV‐1 and HSV‐2. Kd‐AC was highly active against HSV‐1 (EC50 = 0.97 μg/ml, SI > 206.1) and HSV‐2 (EC50 = 0.72 μg/ml, SI > 277.7). Flavonoids 1 and 2 showed anti‐HSV‐1 (EC50 = 7.4 μg/ml; SI > 27 and EC50 = 5.8 μg/ml; SI > 8.6, respectively) and anti‐HSV‐2 (EC50 = 9.0 μg/ml; SI > 22.2 and EC50 = 36.2 μg/ml; SI > 5.5, respectively) activities, suggesting the contribution of additional substances to the antiviral activity. 相似文献
992.
993.
Light induced isomerization of piperlonguminine (1) to scutifoliamide A (2), isopiperlonguminine (3) and hoffmannseggiamide A (4) is reported in this work. In vivo antihyperlipidemic study showed that a mixture of 1 and 2 (1:1) had significantly decreased serum total cholesterol (TC) and triglyceride (TG) in rats, which were similar to those of the pure 1 and simvastatin. Additionally, 2 was less toxic on HepG2 liver cell than the 1 and simvastatin. 相似文献
994.
Bioassay guided fractionation of the roots of Lantana montevidensis (Verbenaceae) has resulted in the isolation and identification of three new triterpenoids; 13β-hydroxy-3-oxo-olean-11-en-28-oic acid (1), 12β,13β-dihydroxyolean-3-oxo-28-oic acid (2) and 12β,13β,22β-trihydroxyolean-3-oxo-28-oic acid (3) in addition to nine known compounds: oleanonic acid (4), oleanolic acid (5), 3β,25β-dihydroxy-olean-12-en-28-oic acid (6), lantadene A (7), 19α-hydroxy-3-oxo-olean-12-en-28-oic acid (8) pomolic acid (9), camaric acid (10) together with β-sitosterol (11) and β-sitosterol-3-O-β-d-glucoside (12). The structures of the isolated metabolites were elucidated based on comprehensive 1D and 2D NMR spectroscopic data as well as HR-ESI–MS. The extracts and the isolated metabolites were evaluated for their antiprotozoal and antimicrobial activities. Compound 2 showed antibacterial activity against Staphylococcus aureus and methicillin resistant S. aureus with IC50 values against both organisms of 2.1 μM and compound 10 showed activity against same organisms with IC50 values 8.74 and 8.09 μM, respectively, compared to the positive control ciprofloxacin (IC50 = 0.3 μM against S. aureus and MRSA). Compounds 1, 4, 5, 6, and 10 showed moderate antileishmanial activity with IC50 values ranging between (2.54–14.95 μM) and IC90 values ranging between (11.90–19.47 μM), using pentamidine as a control (IC50 values 2.09 ≥ 16.8 μM) and IC90 values ranging between (4.72 ≥ 16.8 μM). These compounds also showed highly potent antitrypanosomal activity with IC50 values ranging between (0.39–7.12 μM) and IC90 values ranging between (1.91–10.51 μM), which are more efficient than the DFMO, the antitrypanosomal drug employed as positive control (IC50 and IC90values 11.82 and 30.82 μM). 相似文献
995.
Four new dammarane-type saponins jujubosides F–J, together with six known compounds were isolated from the seeds of Ziziphus jujube. Their structures were elucidated on the basis of chemical and spectroscopic evidences. Compounds 1–10 showed moderate inhibitory effects against pro-inflammatory cytokine TNF-α release in LPS-induced RAW 246.7 macrophages. 相似文献
996.
Two new phenanthrene alkaloids, beilschglabrines A (1) and B (2) were isolated from the stem bark of Beilschmiedia glabra, together with lupeol, taraxerol, and 24-methylenelanosta-7,9-diene-3β-15α-diol. The structures of the isolated compounds were elucidated by extensive spectroscopic data analysis and comparison with respective literature data. The compounds were tested for DPPH radical scavenging, acetylcholinesterase and lipoxygenase inhibitory activities. Compound 1 displayed considerable activity in the acetylcholinesterase (IC50 50.4 μM), the DPPH radical scavenging (IC50 115.9 μM) and the lipoxygenase (IC50 32.8 μM) assays. 相似文献
997.
Chemical characterization as well as antioxidant and anti-tumor activity are reported for isolated metabolites from Teucrium polium L. (Lamiaceae). Structures were identified using standard MS and NMR spectroscopic methods. Sesquiterpene absolute stereochemistry was determined based on a modified Mosher’s reaction. Biological activity was evaluated by a cupric reducing antioxidant capacity (CUPRAC) assay and select compounds screened for anti-tumor activity. (1R,4S,10R) 10,11-dimethyl-dicyclohex-5(6)-en-1,4-diol-7-one and (R)-mandelonitrile-β-laminaribioside, together with ten previously reported compounds were identified. Antioxidant versus tumor-inhibition relationships was examined. 相似文献
998.
From the roots of Euphorbia ebracteolata Hayata, three new diterpenes, Ebracteolatas A–C, based on the rosane (1–2) and lathyrane (3) skeleton, were isolated together with four known ones (4–7). Their structures and relative configurations were elucidated on the basis of spectroscopic methods, especially 2D NMR techniques. Compounds 1, 6, and 7 exhibited moderate cytotoxic effects against five cancer cell lines. 相似文献
999.
Xin Shi Yongqiang Deng Huajing Wang Guanghui Ji Wenlong Tan Tao Jiang 《MABS-AUSTIN》2016,8(3):574-584
Although dengue virus (DENV) infection severely threatens the health of humans, no specific antiviral drugs are currently approved for clinical use against DENV infection. Attachment and fusion are 2 critical steps for the flavivirus infection, and the corresponding functional epitopes are located at E protein domain III (E-DIII) and domain II (E-DII), respectively. Here, we constructed a bispecific antibody (DVD-1A1D-2A10) based on the 2 well-characterized anti-DENV monoclonal antibodies 1A1D-2 (1A1D) and 2A10G6 (2A10). The 1A1D antibody binds E-DIII and can block the virus attaching to the cell surface, while the 2A10 antibody binds E-DII and is able to prevent the virus from fusing with the endosomal membrane. Our data showed that DVD-1A1D-2A10 retained the antigen-binding activity of both parental antibodies. Importantly, it was demonstrated to be significantly more effective at neutralizing DENV than its parental antibodies both in vitro and in vivo, even better than the combination of them. To eliminate the potential antibody-dependent enhancement (ADE) effect, this bispecific antibody was successfully engineered to prevent Fc-γ-R interaction. Overall, we generated a bispecific anti-DENV antibody targeting both attachment and fusion stages, and this bispecific antibody broadly neutralized all 4 serotypes of DENV without risk of ADE, suggesting that it has great potential as a novel antiviral strategy against DENV. 相似文献
1000.