辅酶Q10的合成

以还原型辅酶Q0(氢醌,Ⅳ)为母环,杂多酸为催化剂,与末端羟基取代的异戊二烯单元—(E)-1-苯磺酰基-2-甲基-4-羟基-2-丁烯(Ⅲ)进行偶联反应,溴苄酚羟基保护,制得6-(4-苯磺酰基-3-甲基-2-丁烯)-基-2,3-二甲氧基-5-甲基氢醌双苄醚(Ⅴ),收率75.0%,Ⅴ再与茄尼基溴(Ⅵ)偶联后制得接砜产物(Ⅶ),收率45.0%,Ⅶ经钠还原脱除苯磺酰基、硝酸铈铵氧化制得辅酶Q10(Ⅰ),收率30%。中间体与产物经测熔点、1HNMR和FTIR分析鉴定和确证结构。     

辅酶Q10的合成

以茄尼醇和2，3－二甲氧基－5－甲基－1，4－苯醌为原料合成全反式辅酶Q10。首先以茄尼醇合成全反式侧链四十碳十烯－1－醇，再和2，3－二甲氧基－5－甲基－1，4－苯醌的还原产物在无水氯化锌存在下缩合。缩合反应收率为20％。     

重要的原料药—辅酶Q10

辅酶Q10的合成方法有4种生物提取法、微生物发酵法、半化学合成法、化学合成法,其中微生物发酵法是近几年国内外开发的热点,被认为是较有前途的合成工艺.日本是最主要的辅酶Q10生产国,据统计,全球90%的辅酶Q10来自日本,日清制粉和协和发酵工业公司是产量最高的两家公司.我国目前采用生物提取法生产辅酶Q10总生产能力约为600kg/a,而2000年我国几个主要海关辅酶Q10的进口量就达14689kg,出口量为1278kg,市场缺口较大.我国茄呢醇生产能力接近100t/a(折百),应充分利用原料资源优势,攻克半合成法生产辅酶Q10的难关.     

微生物发酵法生产辅酶Q10的研究进展

辅酶Q10由于具有多种生理功能而得到广泛应用,介绍了近年来微生物发酵法生产辅酶Q10在高产菌株的筛选、传统方法诱变育种、基因工程定向育种、发酵工艺优化、提取纯化工艺优化和定量分析等方面的研究进展.     

辅酶Q10对H_2O_2损伤PC12细胞保护作用的实验研究

研究通过H2O2诱导的PC12细胞建立阿尔茨海默症氧化损伤细胞模型,以细胞活性、丙二醛含量、谷胱甘肽含量及谷胱甘肽转移酶活性水平为指标,检测Co Q10对PC12细胞氧化应激损伤的保护作用。结果表明Co Q10能够提高H2O2所致PC12细胞的细胞活力的降低,降低了由H2O2诱导的脂质过氧化程度,并且可以抑制H2O2诱导的PC12细胞GSH含量及GST活性的降低。Co Q10对H2O2损伤的PC12细胞具有保护作用,可能是通过降低脂质过氧化程度且提高谷胱甘肽含量及谷胱甘肽转移酶活性实现的。     

负载辅酶Q10的两亲性聚肽-壳聚糖复合纳米粒的制备及性质研究

以两亲性聚肽-壳聚糖复合体系为壁材,采用自组装及离子凝聚法制备负载辅酶Q10的纳米粒子,探讨了制备纳米粒子的较佳条件,采用高分辨率透射电镜、动态激光散射仪、紫外光谱及Zeta电位分析仪对优化的聚肽-壳聚糖复合体系纳米粒子进行表征,结果表明:聚肽-壳聚糖复合体系纳米粒子是具有壳核结构的球型粒子;纳米粒子粒径大小在80 nm到300 nm之间,粒径分布较均匀,稳定性较好,粒子的载药率为3.46±0.3%,包封率为59.7±2.1%。24 h的累积释放为75%。     

生物发酵产物中辅酶Q_(10)的快速分离柱高效液相色谱法测定

研究了用快速分离柱高效液相色谱法测定生物发酵产物中辅酶Q10的方法。发酵法得到的样品经匀浆后用四氢呋喃提取,提取液以ZORBAX Stab le Bound(4.6×50 mm,1.8μm)C18快速分离柱为固定相,m(甲醇)∶m(四氢呋喃)=4∶1为流动相分离,流速为2.0 mL/m in;在该色谱条件下,辅酶Q10在2.0 m in内可达到基线分离;用紫外二极管矩阵检测器检测。方法标准回收率为96%~102%,相对标准偏差为0.78%~1.22%。方法用于几种发酵样品中辅酶Q10的测定,结果满意。     

辅酶Q10的合成与应用

以茄尼醇、异戊二烯和辅酶Q0作为主要原料,通过溴化、加成和缩合3步反应合成了目标产物辅酶Q10.其中溴化和加成反应一次收率分别为95%和90%,缩合反应重复收率在70%左右.生产规模为5kg/次.并介绍了辅酶Q10的应用和市场需求.     

多策略代谢工程大肠杆菌高效生产辅酶Q10

Escherichia coli BW25113 was metabolically engineered for CoQ10 production by replacing ispB with ddsA from Gluconobacter suboxydans.Effects of precursor balance and reduced nicotinamide-adenine dinucleotide phosphate (NADPH) availability on CoQ10 production in E.coli were investigated.The knockout of pykFA along with pck overexpression could maintain a balance between glyceraldehyde 3-phosphate and pyruvate,increasing CoQ10 production.Replacement of native NAD-dependent gapA with NADP-dependent gapC from Clostridium acetobutylicum,together with the overexpression of gapC,could increase NADPH availability and then enhanced CoQ10 production.Three effects,overexpressions of various genes in CoQ biosynthesis and central metabolism,different vectors and culture conditions on CoQ10 production in E.coli,were all investigated.The investigation of different vectors indicated that low copy number vector may be more beneficial for CoQ10 production in E.coli.The recombinant E.coli (△ispB::ddsA,△pykFA and △gapA::gapC),harboring the two plasmids encoding pck,dxs,idi and ubiCA genes under the control of PT5 on pQE30,ispA,ddsA from Gluconobacter suboxydans and gapC from Clostridium acetobutylicum under the control of PBAD on pBAD33,could produce CoQ10 up to 3.24 mg·g-1 dry cell mass simply by changing medium from M9YG to SOB with phosphate salt and initial culture pH from 7.0 to 5.5.The yield is unprecedented and 1.33 times of the highest production so far in E.coli.     

辅酶Q_(10)化学合成方法与工艺研究进展评述

辅酶Q10是一种具有重要生理和药理作用的生命活性物质,用途十分广泛。特别是近年来随着对其生理和药理作用认识的不断深入,辅酶Q10已经成为了一种重要的药品和保健品。笔者根据半个世纪以来有关辅酶Q10化学合成的各种文献报道,对辅酶Q10现有的各种化学合成路线及其工艺优劣进行了介绍和比较,重点介绍了从烟草中提取天然茄尼醇为原料的半化学合成辅酶Q10方法,并阐明了化学合成辅酶Q10的关键因素和发展方向。     

Coenzyme q10 ameliorates ultraviolet B irradiation induced cell death through inhibition of mitochondrial intrinsic cell death pathway

Ultraviolet B (UVB) induces cell death by increasing free radical production, activating apoptotic cell death pathways and depolarizing mitochondrial membrane potential. Coenzyme Q10 (CoQ10), an essential cofactor in the mitochondrial electron transport chain, serves as a potent antioxidant in the mitochondria. The aim of the present study is to establish whether CoQ10 is capable of protecting neuronal cells against UVB-induced damage. Murine hippocampal HT22 cells were treated with 0.01, 0.1 or 1 μM of CoQ10 3 or 24 h prior to the cells being exposed to UVB irradiation. The CoQ10 concentrations were maintained during irradiation and 24 h post-UVB. Cell viability was assessed by counting viable cells and MTT conversion assay. Superoxide production and mitochondrial membrane potential were measured using fluorescent probes. Levels of cleaved caspase-9, caspase-3, and apoptosis-inducing factor (AIF) were detected using immunocytochemistry and Western blotting. The results showed that UVB irradiation decreased cell viability and such damaging effect was associated with increased superoxide production, mitochondrial depolarization, and activation of caspase-9 and caspase-3. Treatment with CoQ10 at three different concentrations started 24 h before UVB exposure significantly increased the cell viability. The protective effect of CoQ10 was associated with reduction in superoxide production, normalization of mitochondrial membrane potential and inhibition of caspase-9 and caspase-3 activation. It is concluded that the neuroprotective effect of CoQ10 results from inhibiting oxidative stress and blocking caspase-3 dependent cell death pathway.     

Chromosomal Engineering of Escherichia coli for Efficient Production of Coenzyme Q10

The plasmid-expression system is routinely plagued by potential plasmid instability. Chromosomal in-tegration is one powerful approach to overcome the problem. Herein we report a plasmid-free hyper-producer E. coli strain for coenzyme Q10 production. A series of integration expression vectors, pxKC3T5b and pxKT5b, were constructed for chemically inducible chromosomal evolution （multiple copy integration） and replicon-free and markerless chromosomal integration （single copy integration）, respectively. A coenzyme Q10 hyper-producer Es-cherichia coli TBW20134 was constructed by applying chemically inducible chromosomal evolution, replicon-free and markerless chromosomal integration as well as deletion of menaquinone biosynthetic pathway. The engineered E. coli TBW20134 produced 10.7 mg per gram of dry cell mass （DCM） of coenzyme Q10 when supplemented with 0.075 g·L^-1 of 4-hydroxy benzoic acid;this yield is unprecedented in E. coli and close to that of the commercial producer Agrobacterium tumefaciens. With this strain, the coenzyme Q10 production capacity was very stable after 30 sequential transfers and no antibiotics were required during the fermentation process. The strategy presented may be useful as a general approach for construction of stable production strains synthesizing natural products where various copy numbers for different genes are concerned.     

Coenzyme Q10: Novel Formulations and Medical Trends

The aim of this review is to shed light over the most recent advances in Coenzyme Q₁₀ (CoQ₁₀) applications as well as to provide detailed information about the functions of this versatile molecule, which have proven to be of great interest in the medical field. Traditionally, CoQ₁₀ clinical use was based on its antioxidant properties; however, a wide range of highly interesting alternative functions have recently been discovered. In this line, CoQ₁₀ has shown pain-alleviating properties in fibromyalgia patients, a membrane-stabilizing function, immune system enhancing ability, or a fundamental role for insulin sensitivity, apart from potentially beneficial properties for familial hypercholesterolemia patients. In brief, it shows a remarkable amount of functions in addition to those yet to be discovered. Despite its multiple therapeutic applications, CoQ₁₀ is not commonly prescribed as a drug because of its low oral bioavailability, which compromises its efficacy. Hence, several formulations have been developed to face such inconvenience. These were initially designed as lipid nanoparticles for CoQ₁₀ encapsulation and distribution through biological membranes and eventually evolved towards chemical modifications of the molecule to decrease its hydrophobicity. Some of the most promising formulations will also be discussed in this review.     

Characterisation and Skin Distribution of Lecithin-Based Coenzyme Q10-Loaded Lipid Nanocapsules

The purpose of this study was to investigate the influence of the inner lipid ratio on the physicochemical properties and skin targeting of surfactant-free lecithin-based coenzyme Q10-loaded lipid nanocapsules (CoQ10-LNCs). The smaller particle size of CoQ10-LNCs was achieved by high pressure and a lower ratio of CoQ10/GTCC (Caprylic/capric triglyceride); however, the zeta potential of CoQ10-LNCs was above /− 60 mV/ with no distinct difference among them at different ratios of CoQ10/GTCC. Both the crystallisation point and the index decreased with the decreasing ratio of CoQ10/GTCC and smaller particle size; interestingly, the supercooled state of CoQ10-LNCs was observed at particle size below about 200 nm, as verified by differential scanning calorimetry (DSC) in one heating–cooling cycle. The lecithin monolayer sphere structure of CoQ10-LNCs was investigated by cryogenic transmission electron microscopy (Cryo-TEM). The skin penetration results revealed that the distribution of Nile red-loaded CoQ10-LNCs depended on the ratio of inner CoQ10/GTCC; moreover, epidermal targeting and superficial dermal targeting were achieved by the CoQ10-LNCs application. The highest fluorescence response was observed at a ratio of inner CoQ10/GTCC of 1:1. These observations suggest that lecithin-based LNCs could be used as a promising topical delivery vehicle for lipophilic compounds.     

烟草叶片组织块悬浮培养合成辅酶Q_(10)的研究

以新鲜烟草叶片制得的组织块为研究对象,建立了一种烟叶组织块悬浮培养合成辅酶Q10的方法。考察了培养温度、pH值、培养时间对辅酶Q10合成的影响。另外,采用均匀设计法对培养液中烟酸、盐酸硫胺素、半胱氨酸、对羟基苯甲酸、硫酸镁质量浓度进行了优化。在最适的培养条件下,烟草叶片组织块中辅酶Q10的质量分数达到208.09μg/g,比烟草叶片中的初始质量分数提高了18.7倍。文中建立的烟草叶片组织块悬浮培养合成辅酶Q10的方法具有周期短、操作简单的特点,是一种高效生产辅酶Q10的方法。     

Effect of antioxidant-enriched foods on plasma Coenzyme Q10 and total antioxidant capacity

Twenty healthy subjects integrated their diet with two types of products sequentially: In the first phase (first 14 days), the volunteers were given the following food items not supplemented with vitamin E (vit. E) or Coenzyme Q₁₀ (CoQ₁₀): breakfast, 250 mL skimmed milk; mid-morning snack, 330 mL fruit juice; mid-afternoon snack, low-fat yogurt 125 g; after dinner, low-fat dessert 110 g. In the second phase, from day 14 to day 35, the same items were added with vit. E and CoQ₁₀ (a total daily supplementation of 19.4 mg CoQ₁₀ and 13.7 mg vit.E). After taking the supplemented products for 2 weeks, plasma CoQ₁₀ reached 1.30 µg/mL, nearly twice the initial values. These levels further increased after 3 weeks of supplementation. Vit. E levels significantly (p <0.001) increased only after 3 weeks of supplementation, reaching 7.9 ± 2.8 µg/mL, 39% more than the initial value. The total plasma fatty acid pattern did not change substantially throughout the study. The increase of the total antioxidant capacity of plasma was significant (p <0.001) for days 28 and 35, with values close to 0.24 ± 0.09 mM Trolox (a nearly 60% increase).     

The Effect of Methylmalonic Acid Treatment on Human Neuronal Cell Coenzyme Q10 Status and Mitochondrial Function

Methylmalonic acidemia is an inborn metabolic disease of propionate catabolism, biochemically characterized by accumulation of methylmalonic acid (MMA) to millimolar concentrations in tissues and body fluids. However, MMA’s role in the pathophysiology of the disorder and its status as a “toxic intermediate” is unclear, despite evidence for its ability to compromise antioxidant defenses and induce mitochondrial dysfunction. Coenzyme Q₁₀ (CoQ₁₀) is a prominent electron carrier in the mitochondrial respiratory chain (MRC) and a lipid-soluble antioxidant which has been reported to be deficient in patient-derived fibroblasts and renal tissue from an animal model of the disease. However, at present, it is uncertain which factors are responsible for inducing this CoQ₁₀ deficiency or the effect of this deficit in CoQ₁₀ status on mitochondrial function. Therefore, in this study, we investigated the potential of MMA, the principal metabolite that accumulates in methylmalonic acidemia, to induce a cellular CoQ₁₀ deficiency. In view of the severe neurological presentation of patients with this condition, human neuroblastoma SH-SY5Y cells were used as a neuronal cell model for this investigation. Following treatment with pathological concentrations of MMA (>0.5 mM), we found a significant (p = 0.0087) ~75% reduction in neuronal cell CoQ₁₀ status together with a significant (p = 0.0099) decrease in MRC complex II–III activity at higher concentrations (>2 mM). The deficits in neuronal CoQ₁₀ status and MRC complex II–III activity were associated with a loss of cell viability. However, no significant impairment of mitochondrial membrane potential (ΔΨm) was detectable. These findings indicate the potential of pathological concentrations of MMA to induce a neuronal cell CoQ₁₀ deficiency with an associated loss of MRC complex II–III activity. However, in the absence of an impairment of ΔΨm, the contribution this potential deficit in cellular CoQ₁₀ status makes towards the disease pathophysiology methylmalonic acidemia has yet to be fully elucidated.     

Effects of Endurance Training on the Coenzyme Q Redox State in Rat Heart,Liver, and Brain at the Tissue and Mitochondrial Levels: Implications for Reactive Oxygen Species Formation and Respiratory Chain Remodeling

Sixteen adult, 4-month-old male Wistar rats were randomly assigned to the training group (n = 8) or the control group (n = 8). We elucidated the effects of 8 weeks of endurance training on coenzyme Q (Q) content and the formation of reactive oxygen species (ROS) at the tissue level and in isolated mitochondria of the rat heart, liver and brain. We demonstrated that endurance training enhanced mitochondrial biogenesis in all tested organs, while a significant increase in the Q redox state was observed in the heart and brain, indicating an elevated level of QH₂ as an antioxidant. Moreover, endurance training increased the mQH₂ antioxidant pool in the mitochondria of the heart and liver, but not in the brain. At the tissue and isolated mitochondria level, an increase in ROS formation was only observed in the heart. ROS formation observed in the mitochondria of individual rat tissues after training may be associated with changes in the activity/amount of individual components of the oxidative phosphorylation system and its molecular organization, as well as with the size of the oxidized pool of mitochondrial Q acting as an electron carrier in the respiratory chain. Our results indicate that tissue-dependent changes induced by endurance training in the cellular and mitochondrial QH₂ pool acting as an antioxidant and in the mitochondrial Q pool serving the respiratory chain may serve important roles in energy metabolism, redox homeostasis and the level of oxidative stress.     

Water-Soluble Coenzyme Q10 Inhibits Nuclear Translocation of Apoptosis Inducing Factor and Cell Death Caused by Mitochondrial Complex I Inhibition

The objectives of the study were to explore the mechanism of rotenone-induced cell damage and to examine the protective effects of water-soluble Coenzyme Q10 (CoQ10) on the toxic effects of rotenone. Murine hippocampal HT22 cells were cultured with mitochondrial complex I inhibitor rotenone. Water-soluble CoQ10 was added to the culture media 3 h prior to the rotenone incubation. Cell viability was determined by alamar blue, reactive oxygen species (ROS) production by dihydroethidine (DHE) and mitochondrial membrane potential by tetramethyl rhodamine methyl ester (TMRM). Cytochrome c, caspase-9 and apoptosis-inducing factor (AIF) were measured using Western blotting after 24 h rotenone incubation. Rotenone caused more than 50% of cell death, increased ROS production, AIF nuclear translocation and reduction in mitochondrial membrane potential, but failed to cause mitochondrial cytochrome c release and caspase-9 activation. Pretreatment with water-soluble CoQ10 enhanced cell viability, decreased ROS production, maintained mitochondrial membrane potential and prevented AIF nuclear translocation. The results suggest that rotenone activates a mitochondria-initiated, caspase-independent cell death pathway. Water-soluble CoQ10 reduces ROS accumulation, prevents the fall of mitochondrial membrane potential, and inhibits AIF translocation and subsequent cell death.     

Angptl2 is a Marker of Cellular Senescence: The Physiological and Pathophysiological Impact of Angptl2-Related Senescence

Cellular senescence is a cell fate primarily induced by DNA damage, characterized by irreversible growth arrest in an attempt to stop the damage. Senescence is a cellular response to a stressor and is observed with aging, but also during wound healing and in embryogenic developmental processes. Senescent cells are metabolically active and secrete a multitude of molecules gathered in the senescence-associated secretory phenotype (SASP). The SASP includes inflammatory cytokines, chemokines, growth factors and metalloproteinases, with autocrine and paracrine activities. Among hundreds of molecules, angiopoietin-like 2 (angptl2) is an interesting, although understudied, SASP member identified in various types of senescent cells. Angptl2 is a circulatory protein, and plasma angptl2 levels increase with age and with various chronic inflammatory diseases such as cancer, atherosclerosis, diabetes, heart failure and a multitude of age-related diseases. In this review, we will examine in which context angptl2 was identified as a SASP factor, describe the experimental evidence showing that angptl2 is a marker of senescence in vitro and in vivo, and discuss the impact of angptl2-related senescence in both physiological and pathological conditions. Future work is needed to demonstrate whether the senescence marker angptl2 is a potential clinical biomarker of age-related diseases.