共查询到20条相似文献,搜索用时 78 毫秒
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从易于制备的非手性烯丙醇化合物出发,以经典的的Sharpless不对称环氧化为关键反应构建烯丙仲醇手性中心,共经10步线性步骤以28.6%的总收率首次实现了绣线菊碱C、D全合成路线中BCD三环中间体(-)-4的不对称合成,该合成路线中涉及3个新化合物,其结构经1H NMR, 13C NMR和HR-MS(ESI)表征。 相似文献
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灯盏花中重金属元素的化学形态及分布 总被引:1,自引:0,他引:1
应用火焰原子吸收光谱法(测定铅、铬、镉)及原子荧光光谱法(测定汞、砷)对灯盏花中重金属的化学形态及其分布进行了研究。0.5g经过预处理的试样用浓硝酸消解并经高氯酸冒烟至近干,用水溶解残盐并定容为25mL。在此溶液中分别用上述两方法测定5种金属元素的总量。分别用5种不同萃取溶剂,即乙醇-水(80+20)混合溶液、亚沸重蒸馏水、1mol·L-1氯化钠溶液、乙酸(2+98)溶液及0.6mol·L-1盐酸溶液,对10g试样进行连续超声萃取。各次所得萃取液分别用硝酸和高氯酸按上述方法处理后测定其中5种金属的含量。文中给出了上述金属元素在各种化学形态中的含量及分布状态,此次结果对评价中草药的生物功能及毒性能有参考价值。 相似文献
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天然产物由于具有结构多样性和新颖性,具有独特的生理活性和新的作用机制,因此是开展化学生物学研究的重要工具,同时也是创新药物和先导化合物的重要来源.最近,我们研究发现天然活性化合物腺花素能够在体内和体外诱导维甲酸敏感和耐药的急性粒细胞性白血病细胞发生分化,有效延长白血病小鼠生存时间.在此基础上,以腺花素为分子探针,"垂钓"其潜在的靶分子,结果发现腺花素特异性靶向过氧化还原酶(Peroxiredoxin)Ⅰ//Ⅱ蛋白,导致H2O2的积聚,H2O2作为第二信使可诱导白血病细胞分化的信号通路.本文对这些工作做了论述和展望. 相似文献
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化学与生物学的交叉与融合产生了新学科——化学生物学,开拓了化学和生物学研究的新领域,使人类得以从分子水平来阐释生命过程,揭示生命的奥秘。分子识别和组装是体系的构筑与功能集成的基础,也是自然界生物进行信息存贮、复制和传递的基础,以此来研究构筑具有特定生物学功能的超分子体系,对揭示生命现象和过程具有重要意义。本文结合我们的研究工作从(1)谷胱甘肽过氧化物酶(GPX)模拟与底物识别;(2)医用再生材料与活性支架;(3)类病毒颗粒的组装与解组装3个方面讨论了化学生物学中的识别与组装的意义。 相似文献
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New Diterpenoid Alkaloids from Spiraea japonica var. Ovalifolia 总被引:2,自引:0,他引:2
Guo Ying ZUO Hong Ping HE Xin HONG Wei Ming ZHU Yi Ming HU Xiao Sheng YANG Xiao Jiang HAO* Laboratory of Phytochemistry Kunming Institute of Botany Chinese Academy of Sciences Kunming Kunming Hospital PLA Kunming 《中国化学快报》2001,(2)
In the investigation of the chemical constituents of Spireae japonica L. f. var. ovalifolia (Rosaceae), a shrub originated in Songming, Yunnan, five new diterpenoid alkaloids, 19-O-deethylspiramine N (1), deacetylspiramine S (2), spiramidine A (3), spiramidine B (4) and deacetylspiramine F (5), were isolated from aerial parts of the plant and structurally elucidated. Compound 1, a white amorphous powder with [(]+17.99 (c, 0.26, MeOH ), was determined to have the molecular formula of C20H… 相似文献
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Hong Ping HE Yue Mao SHEN Xiao Sheng YANG Bin Gui WANG Ling LI Xiao Jiang HAO * Laboratory of Phytochemistry Kunming Institute of Botany the Chinese Academy of Sciences Kunming . The Key Laboratory of Chemistry for Natural Prod 《中国化学快报》2001,(1)
Spiraea japonica L. (Rosaceae) is widely distributed in Yunnan Provence, P. R. China. Previous chemical investigations on S. japonica and its varieties have led to the report of 7 new atisane-type diterpenoids and 38 new diterpene alkaloids of atisine- and hetisine-type1-11. This paper describes the isolation and structure elucidation of two new diterpene alkaloids named spiratines A and B (1-2). Their structures were elucidated on the basis of 1D and 2D NMR experiments (HMQC, HMBC, 1… 相似文献
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Hai‐Yang Liu Suo Gao Ying‐Tong Di Chang‐Xiang Chen Yang Lü Li Zhang Qi‐Tai Zheng Xiao‐Jiang Hao 《Helvetica chimica acta》2007,90(7):1386-1390
A novel ent‐atisane lactone, spiramilactone E ( 1 ), was isolated from Spiraea japonica var. acuta Yu . Its structure was elucidated by extensive spectroscopic analyses, and unequivocally confirmed by single‐crystal X‐ray diffraction (Fig. 2). Compound 1 contains a γ‐lactone moiety between the 6‐OH function and C(20), and β‐configuration for the 7‐OH group, in contrast to known related diterpenes previously isolated from the S. japonica complex. 相似文献
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Xiang‐Dong Qin Shu Yang Yan Zhao Li‐Xia Wang Fu‐Cai Ren Fei Wang 《Helvetica chimica acta》2016,99(3):237-240
Three new atisane diterpenoids, spiratisanins A – C ( 1 – 3 , resp.), featuring a phenylacryloxyl substituted ent‐atisane skeleton, were isolated from Spiraea japonica together with two known atisine diterpene alkaloids, spiramine A ( 4 ) and spiradine F ( 5 ). The structures of these new compounds were elucidated as (5β,7α,8α,9β,10α,12α,16β)‐16‐hydroxyatisan‐7‐yl (2E)‐3‐phenylprop‐2‐enoate ( 1 ), (5β,7α,8α,9β,10α,12α,16α)‐16‐hydroxyatisan‐7‐yl (2E)‐3‐phenylprop‐2‐enoate ( 2 ), and (5β,8α,9β,10α,12α,16β)‐16‐hydroxyatisan‐20‐yl (2E)‐3‐phenylprop‐2‐enoate ( 3 ) on the basis of spectroscopic analysis. 相似文献
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GuoYingZUO HongPingHE BinGuiWANG XinHONG YiMingHU XiaoJiangHAO 《中国化学快报》2003,14(4):383-384
A new diterpenoid,15-0-accetylspiraminol(1),was isolated from the aerial parts of Spireae japonica L.f.var.ovalifolia.The structure was charaterized mainly based on spectral analysis. 相似文献
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Yi-Wen Nie Yuan Li Lan Luo Chun-Yan Zhang Wei Fan Wei-Ying Gu Kou-Rong Shi Xiao-Xiang Zhai Jian-Yong Zhu 《Molecules (Basel, Switzerland)》2021,26(21)
There are abundant natural diterpenoids in the plants of the genus Daphne from the Thymelaeaceae family, featuring a 5/7/6-tricyclic ring system and usually with an orthoester group. So far, a total of 135 diterpenoids has been isolated from the species of the genus Daphne, which could be further classified into three main types according to the substitution pattern of ring A and oxygen-containing functions at ring B. A variety of studies have demonstrated that these compounds exert a wide range of bioactivities both in vitro and in vivo including anticancer, anti-inflammatory, anti-HIV, antifertility, neurotrophic, and cholesterol-lowering effects, which is reviewed herein. Meanwhile, the fascinating structure–activity relationship is also concluded in this review in the hope of providing an easy access to available information for the synthesis and optimization of efficient drugs. 相似文献
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<正>One new ent-kaurane diterpenoid,named maoyecrystal L was isolated from the EtOAc extract of the dried leaves of lsodon japonica.Its structure was established by various spectroscopic means and confirmed by X-ray crystallographic analysis. 相似文献
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A New Megastigmane Glucoside and Three New Flavonoid Glycosides from Spiraea prunifolia var. simpliciflora 下载免费PDF全文
A new megastigmane glucoside, simplicifloranoside ( 1 ), and three new flavonol glycosides, prunifolianosides A–C ( 2 – 4 , resp.), were isolated from the aerial parts of Spiraea prunifolia var. simpliciflora. In addition, fifteen known compounds, including five phenolic acids, three lignans, four flavonoids, one eugenol glycoside, and two alkyl‐primeverosides, were also identified. Their structures were elucidated on the basis of detailed spectroscopic analyses and acid hydrolysis. 相似文献
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Ill-Min Chung Kathirvel Kalaiselvi Asokan Sasireka Seung-Hyun Kim 《Journal of Dispersion Science and Technology》2013,34(9):1326-1337
AbstractThe inhibitive performance of methanolic extract of eco-friendly green inhibitor Spiraea cantoniensis (S. cantoniensis) on inhibiting corrosion of mild steel (MS) in 1?M HCl was studied by weight loss, AC-impedance, Fourier transform infrared spectroscopy (FT-IR), Raman, x-ray diffraction (XRD), ultraviolet-visible (UV-Vis), atomic absorption spectroscopy (AAS), and scanning electron microscopy (SEM) analysis. The results showed that the corrosion rate significantly decreased in the presence of the S. cantoniensis inhibitor with a gradual increase in inhibition efficiency at an increased inhibitor concentration. The temperature studies were conducted which included activation energy (Ea), change in enthalpy (ΔH°ads), change in entropy (ΔS°ads), change in free energy (ΔG°ads) and heat of adsorption (Qads). These calculations were helpful to determine the reaction mechanism and proved it as a physisorption type following the Langmuir adsorption isotherm. The analysis of the protective film using FT-IR, Raman, XRD, and SEM analysis clearly showed the potentiality of S. cantoniensis in blocking the MS surface to prevent corrosion by 1?M HCl. The solution analysis via AAS and UV-Vis showed the inhibitive effect of the inhibitor (S. cantoniensis) in both inhibitive and the uninhibitive solution exhibiting the adsorption of the phytochemical molecules on the MS surface. 相似文献