Metabolism of aloesin and related cmpounds by human intestinal bacteria: A bacterial cleavage of the C-glucosyl bond and the subsequent reduction of the acetonyl side chain.
violaceoruber, has excellent anti-inflammatory potential. Herein, a biogenetically modeled approach to synthesize violacin A and twenty-five analogues was described, which involved the preparation of aromatic polyketide precursor through Claisen condensation and its spontaneous cyclization. The inhibitory effect on nitric oxide (NO) production of all synthetic molecules was evaluated by lipopolysaccharide
Violacin A 是一种色满酮衍生物,从Streptomyces violaceoruber的发酵液中分离出来,具有出色的抗炎潜力。在此,描述了一种合成紫罗兰 A 和 25 种类似物的生物遗传学建模方法,该方法涉及通过克莱森缩合及其自发环化制备芳香聚酮化合物前体。通过脂多糖 (LPS) 诱导的 Raw264.7 细胞评估对所有合成分子的一氧化氮 (NO) 产生的抑制作用。结果表明,在C-7上引入脂肪胺基团明显提高了violacin A的抗炎作用,并且侧链上的芳香醚代替酮基有利于提高活性。其中,模拟7a和16d被筛选为最有效的抗炎候选药物。分子机制研究表明,7a和16d由于抑制NF-κB信号通路而获得抗炎能力。
Total synthesis and anti-inflammatory evaluation of violacin A and its analogues
deprotection reaction with Pd-catalytic was involved to avoid the elimination of the hemiacetal hydroxyl at C2. In addition, all synthetic compounds were screened for anti-inflammatory activity against nitric oxide (NO) production using lipopolysaccharide (LPS)-induced Raw264.7 cells. A range of violacin A derivatives 11b, 11d, 11f, 12e, 12g, 13g, 17d-g exhibited stronger anti-inflammatory effect than that
The chalcone synthase (CHS) superfamily of type III polyketidesynthases (PKSs) produces a variety of plant secondary metabolites with remarkable structural diversity and biological activities (e.g., chalcones, stilbenes, benzophenones, acrydones, phloroglucinols, resorcinols, pyrones, and chromones). Here we describe an octaketide-producing novel plant-specific type III PKS from aloe (Aloe arborescens)
III 型聚酮化合物合酶 (PKS) 的查尔酮合酶 (CHS) 超家族产生多种具有显着结构多样性和生物活性的植物次级代谢产物(例如查耳酮、芪、二苯甲酮、丙烯、间苯三酚、间苯二酚、吡喃酮和色酮)。在这里,我们描述了一种来自芦荟(Aloe arborescens)的产生八酮化合物的新型植物特异性 III 型 PKS,与其他植物 CHS 超家族酶具有 50-60% 的氨基酸序列同一性。在大肠杆菌中表达的重组酶催化丙二酰辅酶 A 的七次连续脱羧缩合反应,产生芳香族八酮化合物 SEK4 和 SEK4b,这是已知由结构简单的 III 型 PKS 合成的最长的聚酮化合物。令人惊讶的是,定点诱变显示单个残基 Gly207(对应于 CHS' s 活性位点 Thr197) 决定了聚酮链长度和产品特异性。从小到大的取代(G207A、G207T、G207M、G207L、G207F 和 G207W)导致八酮化合物形
Production of Carminic Acid by Metabolically Engineered <i>Escherichia coli</i>
作者:Dongsoo Yang、Woo Dae Jang、Sang Yup Lee
DOI:10.1021/jacs.0c12406
日期:2021.4.14
Carminicacid is an aromatic polyketide found in scale insects (i.e., Dactylopius coccus) and is a widely used natural red colorant. It has long been produced by the cumbersome farming of insects followed by multistep purification processes. Thus, there has been much interest in producing carminicacid by the fermentation of engineered bacteria. Here we report the complete biosynthesis of carminic