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The structure of tetrahydroneosophoramine has been studied by x-ray structural analysis. Rings A, B, and C have the chair conformation, and ring D the half-chair conformation. On the basis of a semiquantitative analysis it has been shown that the strains in the molecules of tetrahydroneosophoramine and of matrine are of the same order of magnitude.  相似文献   

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The structure of tetrahydroneosophoramine has been studied by x-ray structural analysis. Rings A, B, and C have the chair conformation, and ring D the half-chair conformation. On the basis of a semiquantitative analysis it has been shown that the strains in the molecules of tetrahydroneosophoramine and of matrine are of the same order of magnitude.Institute of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Institute of Crystallography, Academy of Sciences of the USSR, Moscow. V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 751–757, November–December, 1981.  相似文献   

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王晓方  胡殷  潘启发  杨瑞龙  龙重  刘柯钊 《化学进展》2018,30(12):1803-1818
铀氮化物因其独特的物理化学性质及优良的性能而成为核燃料循环系统中重要的燃料材料,是核领域的研究热点材料之一。此外,铀氮化物也被用作抗腐蚀涂层材料,在金属铀的表面腐蚀防护领域具有重要的应用价值。在铀-氮体系中,五种结构铀氮化物,包括NaCl型UN、HgIn型UN、Mn2O3型α-U2N3、La2O3型β-U2N3和CaF2型UN2,已经被确认并进行了广泛研究。但是到目前为止,由于铀氮化物复杂的非化学计量比问题,导致对上述物相之间的转化关系的认识仍不清楚;而不同化学计量比的铀氮化物由于其电子结构的差异,使得其基本物理化学性质发生了根本的变化。有关铀氮化物晶体结构和电子结构方面的研究是探讨其优异性能起因的第一步,因此引起研究者的广泛关注。本文在归纳和分析大量文献的基础上,结合本课题组在铀氮化物相关方面的研究成果,着重介绍铀氮化物晶体结构和电子结构方面的主要进展,并对铀氮化物相结构的转化规律以及电子结构的演化规律进行总结,以期为铀氮化物的实验研究和功能应用提供参考。  相似文献   

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The new alkaloid lilidine, isolated for the first time from the epigeal part ofLilium martagon has been studied by special methods. It has the composition B5H6NO2, mp 118–110°C, [α]D-26.3°. The1H and13C NMR spectra were studied in detail. The values of the direct and long-range spin-spin coupling constants between the13C carbon nuclei and the1H nuclei of the alkaloid molecule were measured with the aid of13C-[{su1}H] selective heteronuclear double resonance. The structure of 5-hydroxy-3-methyl-3-pyrrolin-2-one is suggested for lilidine.  相似文献   

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On the basis of the results of a study of the sesquiterpene lactone ajanin fromAjania fastigiate (Winkl.) Poljak. by the methods of IR and PMR spectroscopy and chemical transformations, its structure has been established as 3,4,8-trihydroxy-5,6,7(H)-guaia1(10),11(13)-dien-6,12-olide.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 785–787, November–December, 1979.  相似文献   

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The new spirobenzylisoquinoline base lederine with mp 208–209°C (methanol), []D +13° (c 0.84; chloroform) has been isolated fromCorydalis ledebouriana Kar et Kir andDicentra peregrina (Rudolphi) Fedde. Its structure has been established on the basis of spectral characteristics and chemical reactions.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Pyatigorsk Pharmaceutical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 540–542, July–August, 1980.  相似文献   

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Diptocarpilidine (bp 193–194° (4 mm)) has been isolated from the epigeal part and seeds ofDiptychocarpus strictus (Fisch) Trautv., and its structure has been established as 1-cyano-6-methylsulfinylhexane.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 84–86, January–February, 1984.  相似文献   

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Summary When suberosin is allowed to stand in chloroform at room temperature with access of atmospheric oxygen, photooxidation takes place with the formation of at least three substances: (II), C15H16O4, mp 172–174°C; (III), C15H16O5, mp 184–185°C; and (IV).It has been established by NMR and mass spectroscopy and also by their chemical properties, that (II) is 6-(3-hydroxyisopent-2-en-1-yl)-7-methoxycoumarin (trans-suberenol) and (III) is 6-(1,2-epoxy-3-hydroxyisopentyl)-7-methoxycoumarin (lophopterol). The nature of (IV) has not yet been determined.It has been shown experimentally that no such oxidation takes place with an isomer of (I) — osthole (IX). A scheme for the biogenesis of coumarins in the organism of the plant investigated has been put forward.Leningrad Sanitary-Hygienic Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 131–133, March–April, 1975.  相似文献   

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