萘黄酮 在
NADPH-450 reductase 、 rat liver epoxide hydrolase 、 recombinant human cytochrome P450 1A1 expressed in E. coli 作用下,
以
水 为溶剂,
反应 0.17h,
生成 α-naphthoflavone-5,6-dihydrodiol
参考文献:
名称:
Oxidation of Benzo[a]pyrene by Recombinant Human Cytochrome P450 Enzymes
摘要:
The oxidation of benzo[a]pyrene (B[a]P) was examined using reconstituted systems prepared with recombinant human cytochrome P450 (P450) enzymes 1A1, 1A2, 2C8, 2C10, 2E1, and 3A4 and with microsomes prepared from Saccharomyces cerevisiae expressing recombinant human P450s 2C8, 2C9, and 2C18. Products measured by HPLC included the 3- and 9-phenols, the 4,5-, 7,8-, and 9,10-dihydrodiols (detected in the presence of epoxide hydrolase), and products in the polar fraction eluting immediately after the void volume. The most active enzyme in all reactions was P450 1A1. P450 3A4 and P450 1A2 formed appreciable amounts of several of the products, including the 3-phenol. P450 2C enzymes and P450 2E1 formed relatively low amounts of all B[a]P products. Consideration of these patterns along with knowledge of levels of expression of the P450s in human tissues and previous results with microsomes leads to the conclusion that P450 1A1 should dominate the oxidation of B[a]P in tissues where it is present and inducible. In human liver the level of P450 1A1 is low and P450 3A4, P450 2C subfamily enzymes, and P450 1A2 probably all contribute. Of the human P450s considered here, P450 1A2 was the most active hepatic enzyme forming the 7,8-dihydrodiol. 7,8-Benzoflavone stimulated the oxidation of B[a]P by P450 3A4 and inhibited the oxidations catalyzed by P450 1A2. The extent of inhibition of P450 1A1 was less (than with P450 1A2), probably due to the rapid oxidation of 7,8-benzoflavone by P450 1A1. The major 7,8-benzoflavone product appears to be the 5,6-oxide.
The palladium-catalyzedintramolecular acylation of alkenyl bromides and aldehydes was developed for an efficient synthesis of 4H-chromen-4-ones. With Pd(PPh3)4/Xphos as the catalyst and K2CO3 as the base, this protocol was applied to synthesize a small library of diversely functionalized flavonoids in moderate to good yields in 1,4-dioxane.
开发了钯催化的烯基溴和醛的分子内酰化反应,以有效合成4 H -chromen-4-ones。以Pd(PPh 3)4 / Xphos为催化剂,以K 2 CO 3为碱,该方案被用于合成少量的,功能多样的黄酮类化合物,在1,4-二恶烷中的产率为中等。
Metal-free, visible-light-induced C(sp2)-H functionalization/C O bond formation for the synthesis of flavones using air as an oxidant
A green and practical method for synthesizing high value-added flavones from readily available chalcones based on visible-light-induced C(sp2)-H functionalization /CO bondformation is described. This reaction utilizes organic dye (Rose Bengal) as the photosensitizer and atmospheric oxygen as the green oxidant and oxygen source without any metals and external additive requirement. Through this methodology
描述了一种基于可见光诱导的 C(sp 2 )-H 功能化/C O 键形成,从现成的查耳酮合成高附加值黄酮的绿色实用方法。该反应以有机染料(玫瑰红)为光敏剂,大气中的氧气为绿色氧化剂和氧源,无需任何金属和外加剂。通过这种方法,以中等到良好的收率合成了多种黄酮。
Nowlan et al., Journal of the Chemical Society, 1950, p. 340,342
作者:Nowlan et al.
DOI:——
日期:——
Dunne et al., Journal of the Chemical Society, 1950, p. 1252,1257
作者:Dunne et al.
DOI:——
日期:——
344. Chromones of the naphthalene series. Part I. Transformation of o-aroyloxyacetoarones into o-hydroxydiaroylmethanes