共查询到18条相似文献,搜索用时 62 毫秒
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在植物天然产物合成过程中,氧化反应是其中的关键反应,氧化酶是催化氧化反应不可或缺的生物催化剂,也是利用微生物合成植物天然产物过程中不可或缺的关键酶。介绍了萜类、生物碱、黄酮等植物天然产物骨架的氧化修饰,按照辅基的差异对合成植物天然产物过程中的氧化酶进行分类介绍,阐释了不同辅基参与氧化反应的机理。此外,还介绍了植物天然产物氧化过程在微生物合成过程中的难点,以及提高氧化酶催化效率的方法。最后,对未来合成生物学中氧化酶在微生物合成植物天然产物领域的前景进行了展望。 相似文献
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植物天然产物是一类结构复杂、性能多样的次级代谢产物,广泛应用于食品、药品、化妆品等多个领域。目前植物天然产物的主要来源依赖于从植物中提取,这种生产方式周期长且占用大量耕地。微生物细胞因其生长周期短、操作简便、环境友好、大规模发酵可控等优势而被广泛研究用以替代传统的植物提取法。目前利用微生物细胞工厂合成和转化植物天然产物已成为研究的热点,实现了萜类、黄酮、生物碱、皂苷等多种植物天然产物的合成和转化。本文分别从从头合成和生物转化的角度综述了微生物细胞工厂在植物天然产物合成中的应用,为更加系统、深入地研究植物天然产物的微生物合成与转化提供参考。 相似文献
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植物天然产物结构多样,具有丰富的生理活性与功能。利用微生物细胞工厂生产来源稀缺、获取难度大的植物天然产物具有经济可行、环境友好等优势。本文系统介绍了萜烯、黄酮以及生物碱的生物合成途径及其关键酶,阐述了差异转录组学、同功酶挖掘等途径解析与重构的方法。指出关键酶改造、途径动态调控、代谢区室化与代谢网络再平衡是增大外源途径代谢通量、抑制副产物合成、降低产物毒性与菌株代谢负担、提高目标产物合成能力的有效策略。提出了解析合成植物天然产物关键酶在微生物中的催化特异性机制、开发外源途径的高效组装方法等进一步提高微生物细胞工厂生产效率的建议。 相似文献
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天然产物泛指来源于植物、动物、微生物、海洋生物和矿物的化合物。天然产物的来源有多种途径,从天然产物中寻找有活性的化合物作为先导化合物创制新药是世界药学工作者公认的有效途径之一。天然来源药物可分为原始天然化合物、经半合成或全合成得到的化合物。 相似文献
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Plant natural products are a kind of active substance widely used in pharmaceuticals and foods. However, the current production mode based on plant culture and extraction suffer complex processes and severe concerns for environmental and ecological. With the increasing awareness of environmental sustainability, engineered microbial cell factories have been an alternative approach to produce natural products. Many engineering strategies have been utilized in microbial biosynthesis of complex phytochemicals such as dynamic control and substructure engineering. Meanwhile, Enzyme engineering including directed evolution and rational design has been implemented to improve enzyme catalysis efficiency and stability as well as change promiscuity to expand product spectra. In this review, we discussed recent advances in microbial biosynthesis of complex phytochemicals from the following aspects, including pathway construction, strain engineering to boost the production. 相似文献
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糖基化是天然产物的一种重要基团修饰,主要通过尿苷二磷酸(UDP)-糖基转移酶催化实现,而UDP-糖基供体价格昂贵限制了其应用,构建UDP-糖基供体再生系统可以有效解决该问题。本文从天然产物的体外糖基化修饰入手,阐述了糖基化修饰对天然产物功能的调控作用,比较了目前的糖基化修饰方法,其中基于UDP-糖基转移酶的生物法具备了重要的产业化应用前景。接着总结了各种UDP-糖基供体的合成方式,概述了偶联蔗糖合酶或海藻糖合酶的基于UDP循环的UDP-糖基供体再生系统,重点描述了UDP循环体系在萜类、黄酮类及其他化合物体外糖基化修饰中的应用,从而高效合成具有高附加值的天然产物糖苷化合物。指出偶联蔗糖合酶和UDP-糖基转移酶的循环体系是今后天然产物糖苷化合物合成的重要方式。 相似文献
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Israel Prez-Torres Vicente Castrejn-Tllez María Elena Soto María Esther Rubio-Ruiz Linaloe Manzano-Pech Vernica Guarner-Lans 《International journal of molecular sciences》2021,22(4)
Oxidative stress is important in the pathophysiology of obesity, altering regulatory factors of mitochondrial activity, modifying the concentration of inflammation mediators associated with a large number and size of adipocytes, promoting lipogenesis, stimulating differentiation of preadipocytes to mature adipocytes, and regulating the energy balance in hypothalamic neurons that control appetite. This review discusses the participation of oxidative stress in obesity and the important groups of compounds found in plants with antioxidant properties, which include (a) polyphenols such as phenolic acids, stilbenes, flavonoids (flavonols, flavanols, anthocyanins, flavanones, flavones, flavanonols, and isoflavones), and curcuminoids (b) carotenoids, (c) capsaicinoids and casinoids, (d) isothiocyanates, (e) catechins, and (f) vitamins. Examples are analyzed, such as resveratrol, quercetin, curcumin, ferulic acid, phloretin, green tea, Hibiscus Sabdariffa, and garlic. The antioxidant activities of these compounds depend on their activities as reactive oxygen species (ROS) scavengers and on their capacity to prevent the activation of NF-κB (nuclear factor κ-light-chain-enhancer of activated B cells), and reduce the expression of target genes, including those participating in inflammation. We conclude that natural compounds have therapeutic potential for diseases mediated by oxidative stress, particularly obesity. Controlled and well-designed clinical trials are still necessary to better know the effects of these compounds. 相似文献
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论述该装置第一阶段扩产改造情况。总体目标为原设计负荷的113%,年生产能力达30万t/a。通过理论计算和实际运行经验以及大流量实验,对5个系统进行改造。改造后产量近40t/h;单耗:PX,652kg;AcOH,46kg;综合能耗,164.7kg;产品质量全部达到优级品。 相似文献
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