共查询到19条相似文献,搜索用时 62 毫秒
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以2,4,6-三羟基苯乙酮和2,6-二羟基苯乙酮为原料, 分别通过甲基保护酚羟基、 苯甲酰氯酰化、 Bake-Venkataraman重排、 异戊烯基化、 酸催化关环及EtSLi脱去甲基等6步反应, 以高收率完成了天然5,7-二羟基-3-异戊烯基黄酮(1a, 收率80.6%)和5-羟基-3-异戊烯基黄酮(1b, 收率84.9%)的全合成, 所有化合物均经 1H NMR 和 13C NMR表征确定. 通过密度泛函理论方法对目标产物(1a和1b)的生物活性进行了预测. 结果表明, 3位异戊烯基侧链的存在能大大增强化合物相应的生物活性, 而且是化合物生物活性增强必需的取代基. 另外, 目标产物1a的生物活性高于产物1b, 归因于黄酮类化合物分子中A环上的7-OH属增效基团, 起到增强生物活性的作用, 化合物1a分子中A环上有7-OH, 而化合物1b分子中则无该基团. 本合成方法对其它3-烃基黄酮类天然化合物的合成具有潜在的适用性, 所预测的生物活性结果为3-烃基黄酮类化合物的构效关系研究奠定了基础. 相似文献
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以3-甲氧基甲氧基苯甲醛和2,4,6-三甲氧基-3-异戊烯基苯乙酮为原料,经烷基化和缩合反应合成了新化合物——2’-羟基-4-甲氧基-3,4’,6’-三甲氧甲氧基-3’-异戊烯基査尓酮(6);6经环合反应合成了新化合物——(±)-5,7,3’-三甲氧甲氧基-4’-甲氧基-8-异戊烯基黄烷酮(7);7经脱保护和环合反应实现了天然产物(±)-5,7,3’-三羟基-4’-甲氧基-8-异戊烯基-黄烷酮(1,总收率11.6%)和(±)-5,3’-二羟基-7,8-(2,2-二甲基吡喃)-4’-甲氧基黄烷酮(2,总收率10.5%)的全合成,其中1为新化合物,其结构经1H NMR,IR和MS表征。 相似文献
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以廉价的3,4-二羟基苯甲醛和2,4-二羟基苯乙酮为起始原料,经过C-异戊烯基化,酚羟基保护,羟醛缩合和去保护基等步骤,以32%的总收率完成了天然产物5-异戊烯基紫铆花素的全合成。所有新化合物的结构都经过1H NMR、IR、MS确认。 相似文献
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Flavonoids, composed of a C6-C3-C6 backbone, are a kind of secondary metabolites of natural medicine, which widely exist in the higher plant. They have received extensive attention from all over the world and obtained rapid development owing to widespread distribution, structural complexity, active diversity, and molecular plasticity. Total synthesis of natural products is not only one of the most driving forces in organic chemistry but also the embodiment of the development level of organic synthesis chemistry. Total synthesis research possesses not only important theoretical significance to the development of organic chemistry but also potential marketing prospects to clinical medicine and significant practical value to the development of natural medicine. Flavonoids contain flavan, chalcone, flavone, biflavone, isoflavone, xanthone, pterocarpin, homoisoflavone, flavonol, favonolignan, and some other main structure types. This article summarizes the latest research on first total synthesis, including the plant sources and biological activities, of these main structure types, so as to provide some reference for both the research of first total synthesis of natural flavonoids and the development and utilization of their medicinal value. 相似文献
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Twenty prenylated flavonoids 1-20 were synthesized by glycoside hydrolysis, dehydrogenation, selective O-methylation, O-prenylation and Claisen rearrangement reaction, from abundant and inexpensive natural flavonoids naringin, hespiredin, quercetin and myricetin. Among them, 1-7, 10-15 and 17-20 are novel compounds, the natural product 3,3',4',7-tetramethoxy-8-prenyl-5-hydroxy flavonoid(16) was synthesized in a high yield. Their antiprolirative activities were evaluated in vitro on a panel of three human cancer cell lines(HeLa, HCC1954 and SK-OV-3). The results show that most of the target compounds displayed moderate to potent antiprolirative activities against the three cancer cells with half maximal inhibitory concentration(IC50) values from 0.49 μmol/L to 95.07 μmol/L. Among them, 3',4',7-trimethoxyl-5-hydroxyl-8-prenyl flavonoid(12) exhibited the strongest antiprolirative activity against the three cancer cells mentioned above with IC50 values of 0.91-7.08 μmol/L. 3',7-Dimethoxy-5-O-prenyl flavone(6) and 3',4',7-trimethoxy-5-O-prenyl flavone(10) showed selective antiproliferative activity against HCC1954 cells with IC50 value of 0.49 and 5.32 μmol/L, respectively. 相似文献
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The first total synthesis of naturally occurring mappain has been achieved by a convergent sequence. The key strategy involved in the synthesis of mappain was a (E)‐stilbene formation by Horner–Wadsworth–Emmons reaction of the corresponding prenylated benzaldehyde with a geranylated benzyl phosphonate. 相似文献
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The first enantioselective total synthesis of 5-acetoxygoniothalamin 1 and 5-acetoxyisogoniothalamin oxide 2 was achieved through the Sharpless kinetic resolution of recemic secondary 2-furylmethanol 5 and the Mitsunobu reaction. At the same time we developed a short synthetic route for 6R-( )-goniothalamin 3 and (6R,7R,8R)-( )-goniothalamin oxide 4. And according to this route the configuration of 5-acetoxygoniothalamin 1 was confirmed as (5S,6S). 相似文献
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以对羟基苯甲醛和2,4-二羟基苯乙酮为起始原料,经过甲氧甲基化、溴代、Ullmann反应、羟醛缩合和脱保护等反应,完成了天然产物双查尔酮Luxenchalcone的全合成,关键步骤为Ullmann反应,重要中间体和目标产物的化学结构经 1H NMR,13C NMR和ESI-MS等表征确认. 相似文献
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First Total Synthesis of Four Benzodioxane Neolignans 总被引:1,自引:0,他引:1
During the last years, 1,4-benzodioxins and 1,4-benzodioxanes have attracted considerable interest, mainly due to their very interesting biological activities. Some of them act as (- or (-blocking agents and could be used in antidepression or antihypertension therapy1. Others exhibit antihyperglycemic properties2, or could act as inhibitors of 5-lipoxygenase3. Moreover, these compounds could also be used for useful synthetic transformations4. While there are many synthetic methods for the synt… 相似文献
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4个天然1,7-二芳基庚烷类化合物的合成 总被引:1,自引:0,他引:1
合成了4个天然1,7-二芳基庚烷类化合物:1-(4′-羟基-3′-甲氧基苯基)-7-(4″-羟基苯基)-5-羟基-3-庚酮(1),1-(4′-羟基-3′-甲氧基苯基)-7-(4″-羟基苯基)-4-庚烯-3-酮(2),1-(3′,4′-二羟基苯基)-7-(4″-羟基苯基)-5-羟基-3-庚酮(3),1-(3′,4′-二羟基苯基)-7-(4″-羟基苯基)-4-庚烯-3-酮(4).化合物1,2,4为首次合成. 相似文献