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The hexane fraction from the roots of Echinops ellenbeckii O. Hoffm. from Ethiopia yielded seven acetylenic thiophenes of which five compounds (1, 3, 4, 6, 7) are reported for the first time in this species: the monothiophenes 5-(penta-1,3-diynyl)-2-(but-3-en-1-ynyl)-thiophene (1), 5-(penta-1,3-diynyl)-2-(4-acetoxy-but-1-ynyl)-thiophene (2), 5-(penta-1,3-diynyl)-2-(3-hydroxy-4-acetoxy-but-1-ynyl)-thiophene (3), 5-(penta-1,3-diynyl)-2-(3,4-diacetoxy-but-1-ynyl)-thiophene (4), 5-(penta-1,3-diynyl)-2-(3-chloro-4-acetoxy-but-1-ynyl)-thiophene (5), 5-(penta-1,3-diynyl)-2-(3,4-epoxy-but-1-ynyl)-thiophene (6) and the dithiophene 5-[(5-acetoxymethyl-2-thienyl)-2-(but-3-en-1-ynyl)]-thiophene (7). Additionally, four fatty acids (C14, C15, C16 and C18), seven fatty acid esters and three long-chain hydrocarbons could be identified. All the structures were elucidated on the basis of spectral data by GC-MS, HRMS and the NMR techniques.  相似文献   

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Chemistry of Natural Compounds - 1. The lipase from cotton seeds possesses lipase, esterase, and tweenase activities. 2. The broad substrate specificity of the lipase is connected with its capacity...  相似文献   

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A fungal strain of Aspergillus sp. (BRF 030) was isolated from the sediments collected in the northeast coast of Brazil, and the cytotoxic activity of its secondary metabolites was investigated against HCT-116 tumour cell line. The cytotoxicity-guided fractionation of the extracts from this fungus cultured in potato-dextrose-sea water for 14 days at room temperature yielded the hetero-spirocyclic γ-lactams pseurotin A (1), pseurotin D (2) and pseurotin FD-838 (7), the alkaloids fumitremorgin C (5), 12,13-dihydroxy fumitremorgin C (6), methylsulochrin (4) and bis(dethio)bis(methylthio)gliotoxin (3). Among them, fumitremorgin C (5) and 12,13-dihydroxy fumitremorgin C (6) were the most active. The cytotoxic activities of the extracts from Aspergillus sp. grown from 7 to 28 days were investigated, and they were associated with the kinetic production of the compounds. The most active extracts (14 and 21 days) were those with the highest relative concentrations of the compounds fumitremorgin C (5) and 12,13-dihydroxy fumitremorgin C (6).  相似文献   

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Conclusions 1. The lipase from cotton seeds possesses lipase, esterase, and tweenase activities.2. The broad substrate specificity of the lipase is connected with its capacity for functioning both in homogeneous and in heterogeneous media. A mechanism of the action of the lipase explaining the specificity of its action is proposed.Institute of the Chemistry of Plant Substances, Academy of Sciences of the UzbekSSR. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 602–607, September–October, 1970.  相似文献   

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Acylsilanes undergo a first-order thermal rearrangement to yield products derived from the insertion of an intermediate siloxycarbene into adjacent CH bonds.  相似文献   

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Bioassay-directed fractionation of an extract of the root and bark of Podocarpus madagascariensis resulted in the isolation of a new totarol diterpenoid (1) in addition to the three known cytotoxic diterpenoids 19-hydroxytotarol (2), totaradiol (3), and 4beta-carboxy-19-nor-totarol (4). The structure of the new compound 1 was established as methyl-13-hydroxy-14-isopropyl-9(11),12,14(8)-podocarpatriene-19-oate on the basis of 1D and 2D NMR spectroscopic interpretation and methylation of 4. All the compounds exhibited cytotoxic activity against the A2780 ovarian cancer cell line.  相似文献   

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The chemical composition of the essential oil from the aerial parts of Chromolaena odorata, collected from Phitsanulok, Thailand was analyzed by means of GC-(FID) and GC-MS. Twenty-two constituents were identified. The major components were pregeijerene (17.6%), germacrene D (11.1%), alpha-pinene (8.4%), beta-caryophyllene (7.3%), vestitenone (6.5%), beta-pinene (5.6%), delta-cadinene (4.9%), geijerene (3.1%), bulnesol (2.9%), and trans-ocimene (2.2%).  相似文献   

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