共查询到20条相似文献,搜索用时 15 毫秒
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Dr. Xin Fang Ying Tong Di Yu Zhang Dr. Zhi Ping Xu Prof. Yang Lu Qian Qian Chen Prof. Qi Tai Zheng Prof. Dr. Xiao Jiang Hao 《Angewandte Chemie (International ed. in English)》2015,54(19):5592-5595
Perforalactone A ( 1 ), a new 20S quassinoid with a unique cagelike 2,4‐dioxaadamantane ring system and a migrated side chain, was isolated from the plant Harrisonia perforata together with two biosynthetically related new quassinoids. The structures of these natural products were elucidated by NMR spectroscopy, X‐ray diffraction analysis, computational modeling, and the CD excitation chirality method. The compounds exhibited notable biological properties, including insecticidal activity against Aphis medicaginis Koch and antagonist activity at the nicotinic acetylcholine receptor of Drosophila melanogaster. The structural features of these compounds may be related to their promising biological characteristics. Their biosynthesis and an alternative origin of quassinoid‐type natural products are also discussed. 相似文献
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Angle Chiaroni Claude Riche Qui Khuong‐Huu Hanh Nguyen‐Ngoc Kinh Nguyen‐Viet Franoise Khuong‐Huu 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(6):711-713
Two minor compounds were isolated from a sample of Harrisonia perforata leaves collected in central Vietnam, namely haperforin B1, C27H32O9, and haperforin D, C27H34O10. Biogenetically, haperforin D and haperforin B1 can be derived from each other by addition or elimination of water. 相似文献
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<正>A novel chromone,named chaetoaurin(1),along with six known chromone derivatives(2-7),was isolated from the ethyl acetate extract of a solid-state fermented culture of Chaetomium aureus.Their structures were elucidated by extensive spectral analysis.All of these compounds were reported from C.aureus for the first time. 相似文献
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The phytochemical studies of the leaves of Licania arianeae Prance (Crysobalanaceae) have led to the identification of ten new chromones, four 5,7-dihydroxy-2-alkylchromones, four 5,7-dihydroxy-6-chloro-2-alkylchromones and two 5,7-dihydroxy-6,8-dichloro-2-alkylchromones. The structures were established from IR, NMR and FAB-MS spectra data including 2D NMR experiments of natural substances and of the methyl derivatives. 相似文献
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Two new benzophenone glycosides, hypersens A and B, along with four known compounds, (S)-(+)-5,7-dihydroxy-2-(1-methylpropyl) chromone (3), 5,7-dihydroxy-2-isopropylchromone (4), urachromone B (5), and 3-8′′ bisapigenin (6), were isolated from Hypericum seniawinii. The structures of new compounds (1 and 2) were elucidated according to comprehensive spectroscopic data analyses. The absolute configurations of 1 and 2 were determined by electronic circular dichroism (ECD) calculations. All isolated compounds were evaluated for their neuroprotective effect using corticosterone-induced PC12 cell injury. In addition, compounds 1–6 were evaluated for their anti-inflammatory activity in lipopolysaccharide-induced RAW 264.7 cells. Compound 6 was a biflavonoid and significantly inhibited the production of nitric oxide with an IC50 value of 11.48 ± 1.23 μM. 相似文献
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Lindsey G. DeRatt Mukesh Pappoppula Aaron Aponick 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(25):8504-8508
The first catalytic enantioselective alkynylation of chromones is reported. In this process, chromones are silylated to form silyloxybenzopyrylium ions that lead to silyl enol ethers after Cu‐catalyzed alkyne addition using StackPhos as a ligand. The outcome of the reaction is impacted by distal ligand substituents with differing electronic character and it was found that successful reactions could be achieved with different ligand congeners by using different solvents. This sequence enables access to different products by protonation or further functionalization, thus increasing complexity in a divergent manner. The transformation is high yielding over a broad scope to provide a variety of useful chromanones in high enantioselectivity. 相似文献
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3—氮杂环取代色酮的合成 总被引:1,自引:0,他引:1
报道了通过1-苯基-3-甲酰基-1,2,5-三唑合成3-杂环取代色酮的结果。化合物的结构经元素分析,紫外光谱,红外光谱,1HNMR及13CNMR谱证实。 相似文献
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Jiang Hongyu Cao Huina Ruan Jingya Zhao Wei Zhang Ying Han Yu Chen Qian Zhang Yi Wang Tao 《Chemistry of Natural Compounds》2022,58(4):623-627
Chemistry of Natural Compounds - One new chromone, 5-hydroxy-8-O-β-D-glucopyranosyl-2-(2-phenylethyl)chromone (1), along with 13 known ones (2–14) were obtained and identified from a 70%... 相似文献
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Pei-Song Yang Jia-Meng Dai Xue-Jiao Gu Wen Xiong De-Quan Huang Shi-Yu Qiu Jun-Na Zheng Yong Li Feng-Xian Yang Min Zhou 《Molecules (Basel, Switzerland)》2022,27(10)
The Cassia (Leguminosae) genus has attracted a lot of attention as a prolific source of alkaloids and chromones with diverse structures and biological properties. The aim of this study is to screen the antiviral compounds from Cassia alata. The extract of the stem bark of this plant was separated using silica gel, MCI, ODS C18, and Sephadex LH-20 column chromatography, as well as semi-preparative HPLC. As a result, three new indole alkaloids, alataindoleins A–C (1–3); one new chromone, alatachromone A (4); and a new dimeric chromone-indole alkaloid, alataindolein D (5) were isolated. Their structures were determined by means of HRESIMS and extensive 1D and 2D NMR spectroscopic studies. Interestingly, alataindolein D (5) represents a new type of dimeric alkaloid with an unusual N-2−C-16’ linkage, which is biogenetically derived from a chromone and an indole alkaloid via an intermolecular nucleophilic substitution reaction. Compounds 1–5 were tested for their anti-tobacco mosaic virus (TMV) and anti-rotavirus activities, and the results showed that compounds 2–4 showed high anti-TMV activities with inhibition rates of 44.4%, 66.5%, and 52.3%, respectively. These rates were higher than those of the positive control (with inhibition rate of 32.8%). Compounds 1 and 5 also showed potential anti-TMV activities with inhibition rates of 26.5% and 31.8%, respectively. In addition, compounds 1–5 exhibited potential anti-rotavirus activities with therapeutic index (TI) values in the range of 9.75~15.3. The successful isolation and structure identification of the above new compounds provided materials for the screening of antivirus drugs, and contributed to the development and utilization of C. alata. 相似文献
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Reactions of the substituted 2‐formyl chromones with aroylhydrazines gave corresponding 2‐(aroylhydrazonomethylidyne) chromones. Then 2‐(3′‐acetyl‐5′‐aryl‐2′,3′‐dihydro‐1′,3′,4′‐oxadiazol‐2′‐yl) chromones were prepared by these 2‐(aroylhydrazonomethylidyne) chromones under refluxing with Ac2O. All target compounds were characterized through elemental analysis and IR, 1H NMR, MS. 相似文献
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A simple one-step synthetic methodology for stereoselective synthesis of E- and Z-3-bromo-2-vinyl chromones in quantitative yield in polar solvents under ambient conditions without the use of catalysts is reported. 相似文献
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Yao H Liao ZX Wu Q Lei GQ Liu ZJ Chen DF Chen JK Zhou TS 《Chemical & pharmaceutical bulletin》2006,54(1):133-135
Two new flavanone glucosides, (2S)-homoeriodictyol 7,4'-di-O-beta-D-glucopyranoside (4) and (2R)-eriodictyol 7,4'-di-O-beta-D-glucopyranoside (5) were isolated from the branches and leaves of Viscum coloratum (KOMAR) NAKAI (Loranthaceae), along with three known flavanone glucosides: (2S)-homoeriodictyol 7-O-beta-D-glucopyranoside (1), (2S)-eriodictyol 7-O-beta-D-glucopyranoside (2), and (2S)-naringenin 7-O-beta-D-glucopyranoside (3). The structures of these compounds were elucidated using spectroscopic methods. The antioxidant activities of these isolated compounds were evaluated by colorimetric methods based on their scavenging effects on hydroxyl radicals and superoxide anion radicals, respectively. All the compounds showed potent albeit varied degrees of antioxidative activities and the structure-activity relationship is discussed. 相似文献
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J. A. Van Allan J. F. Stenberg G. A. Reynolds 《Journal of heterocyclic chemistry》1979,16(8):1663-1665
Certain chromones and benzoxanthones were prepared by heating at 300–325° a mixture of 1-or 2-naphthol with either phenyl o-hydroxybenzoate or o-hydroxynaphthoate or a β-ketoester. The yields and purity of the products are superior to those obtained by the published procedures. 相似文献
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Dr. Mengdan Wang Lu Cheng Prof. Junying Ma Prof. Weiwei Lu Prof. Junling Wang 《European journal of organic chemistry》2023,26(32):e202300456
A transition-metal-free one-pot procedure for the difunctionalization of alkynes by C−C triple bond oxidation and transformation towards chromone derivatives has been developed. It involves cascade reactions for carbonylation of alkynes, base-promoted C−C σ-bond cleavage, and intramolecular cyclization. This procedure provides an efficient protocol for the synthesis of polysubstituted chromones from readily available starting materials. 相似文献