细胞色素P450酶生物转化及新催化反应的最新进展

细胞色素P450酶(P450s或CYPs)是一类广泛存在于生命体中,依赖于亚铁血红素催化多种底物的单加氧酶。一方面,它涉及许多高活性天然产物生物合成的关键步骤,对其生物转化研究有助于提高活性分子的产率和活性;另一方面,其催化涉及金属元素以及辅助因子,其蛋白质改造和新催化反应的研发也不断取得新突破。本文就细胞色素P450酶这两方面的最近研究进展进行了总结与论述。

Development of a CH4 dehydroaromatization–catalyst regeneration fluidized bed system

A pilot-scale methane dehydroaromatization–H_2regeneration fluidized bed system(MDARS)was developed.In the MDARS,the catalyst circulation between a fluidized bed reactor and a fluidized bed regenerator with the help of a catalyst feeder allowed methane dehydroaromatization(MDA)and H_2regeneration to be carried out simultaneously,which is good for maintaining a stable MDA catalytic activity.A fixed bed reactor(FB)and a single fluidized bed reactor(SFB)were also used for a comparative study.The experimental results showed that the catalytic activity in the MDARS was more stable than that in the FB and SFB reactors.The effects of some parameters of MDARS on the CH_4conversion and product selectivity were investigated.To verify the feasibility and reliability of the MDARS,an eight-hour long-term test was carried out,which demonstrated that the operation of the MDARS was stable and that the catalytic activity remained stable throughout the entire experimental period.

Multi-walled carbon nanotubes as novel promoter of catalysts for certain hydrogenation and dehydrogenation reactions

From the chemical catalysis viewpoint,the excellent performance of CNTs in adsorption-activation of H2 and in promoting spillover of adsorbed H-species is very attractive,in addition to their nanosize channels,sp2-C constructed surfaces,and high thermal/electrical conductivity.This review examines some recent progresses of CNTs as a novel support or promoter of catalysts for certain hydrogenation or dehydrogenation reactions,e.g.,hydrogenation-conversion of syngas to yield alcohols and decomposition or steam-reforming of methanol to generate H2,mainly based on recent work carried out in our laboratory.

Easily fabricated and recyclable Pd&Cu@Al catalyst for gram-scale phosphine-free Heck reactions with high TON

A unique Pd＆Cu@Al catalyst was easily fabricated just by immersing commercial aluminum foil in a mixed xylene solution of PdC12 and CuCl2. The catalyst fabrication process led to aluminum oxide coatings in situ, which supported the metal nanoparticles and enhanced their catalytic activities for the phosphine-free Heck reaction of awl halides and styrenes with high turnover number （TON） up to 3.9×10^5. The reaction can be scaled up to at least 100 mmol and has been applied in modification of drug Lapatinib＇s intermediate with low metal residue. This novel catalyst is of good application potential in industrial production because it was extremely easy to be recycled, in regardless of the generation of the insoluble impurities or tars during the reaction processes.

Chemomics and drug innovation

Chemomics is an interdisciplinary study using approaches from chemoinformatics,bioinformatics,synthetic chemistry,and other related disciplines.Biological systems make natural products from endogenous small molecules (natural product building blocks) through a sequence of enzyme catalytic reactions.For each reaction,the natural product building blocks may contribute a group of atoms to the target natural product.We describe this group of atoms as a chemoyl.A chemome is the complete set of chemoyls in an organism.Chemomics studies chemomes and the principles of natural product syntheses and evolutions.Driven by survival and reproductive demands,biological systems have developed effective protocols to synthesize natural products in order to respond to environmental changes;this results in biological and chemical diversity.In recent years,it has been realized that one of the bottlenecks in drug discovery is the lack of chemical resources for drug screening.Chemomics may solve this problem by revealing the rules governing the creation of chemical diversity in biological systems,and by developing biomimetic synthesis approaches to make quasi natural product libraries for drug screening.This treatise introduces chemomics and outlines its contents and potential applications in the fields of drug innovation.