Homochirality of Organic Matter – Objective Law or Curious Incident?

Of the many hypotheses on the origin of biological homochirality on the Earth, the combination of the notion of subatomic particles composing a homochiral pool of primary matter, on the one hand, with the suggestion of the synthesis of chiral organic molecules in the plasma torch generated by super-high-velocity impacts (SHVI) of meteorites, on the other hand, was chosen as the working assumption.     

Kinetics of acetic acid addition to epichlorohydrin in the presence of chromium acetate and chromic anhydride

The kinetics of the reaction between acetic acid and epichlorohydrin in the presence of chromium acetate and chromic anhydride have been studied. The isolation method revealed the reagents reacted with partial orders. A reduction of chromium from the oxidation level +6 to +3 has been observed when chromic anhydride was used as catalyst. A mathematical model for the overall process has been developed and the mechanism of reaction discussed.     

Maresin-1 and Inflammatory Disease

Inflammation is an essential action to protect the host human body from external, harmful antigens and microorganisms. However, an excessive inflammation reaction sometimes exceeds tissue damage and can disrupt organ functions. Therefore, anti-inflammatory action and resolution mechanisms need to be clarified. Dietary foods are an essential daily lifestyle that influences various human physiological processes and pathological conditions. Especially, omega-3 fatty acids in the diet ameliorate chronic inflammatory skin diseases. Recent studies have identified that omega-3 fatty acid derivatives, such as the resolvin series, showed strong anti-inflammatory actions in various inflammatory diseases. Maresin-1 is a derivative of one of the representative omega-3 fatty acids, i.e., docosahexaenoic acid (DHA), and has shown beneficial action in inflammatory disease models. In this review, we summarize the detailed actions of maresin-1 in immune cells and inflammatory diseases.     

基于关联规则与遗传算法的蛋白质二级结构预测

文章通过建立蛋白质二级结构预测的数学模型,运用挖掘与遗传算法相结合的关联规则技术对蛋白质二级结构进行预测,设计并实现了该原型系统。实验表明,该文所采用的基于蛋白质氨基酸疏水性周期规律的预测模型方法较其它相关的二级结构预测方法有较好的准确性、有效性与可行性。     

Use of Beta Cyclodextrin to Remove Cholesterol and Increase Astaxanthin Content in Shrimp Oil

Shrimp oil is extracted from shrimp (Litopenaeus vannamei) cephalothorax and subjected to the removal of cholesterol by β‐cyclodextrin (βCD). Different oil/βCD ratios (1:2, 1:3, and 1:4, w/w) and homogenization times (1, 10, and 20 min) are used. Cholesterol deduction is attained with increasing βCD levels and homogenization time. Astaxanthin content is augmented, while cholesterol concentration is reduced. Nevertheless, oil yield and astaxanthin concentration of treated oil are decreased as βCD levels are increased. To increase the oil yield, the used βCD is further extracted for three times with ethyl acetate at 1:10 (w/v) ratio, in which yield is increased from 44.6% to 64%. Cholesterol removal of 95% is obtained, while astaxanthin content is increased. Lipid oxidation is lowered as indicated by the lower TOTOX value, peroxide value, thiobarbituric acid reactive substances, and p‐anisidine value. However, lipid hydrolysis is slightly increased after treatment. Volatiles, especially aldehydes and alcohols, are decreased after treatment. FTIR spectra confirm the removal of phospholipid, which might be associated with the decreased oil yield after treatment. With the developed process, total fatty acid is increased by 15.6%, in which monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) are augmented. βCD could remove cholesterol, increase astaxanthin and fatty acid content. Practical Applications: Shrimp oil has been known to be a rich source of astaxanthin and PUFAs with health benefit. However, it also contains cholesterol, which can be a drawback for consumption as the supplement. The removal of cholesterol, while maintaining PUFA and astaxanthin could pave a way for promoting the intake of shrimp oil. Use of βCD for oil treatment with subsequent extraction of remaining oil in the used βCD could be implemented with ease. Another advantage of the developed process is to increase both fatty acid and astaxanthin contents in the resulting oil. As a consequence, shrimp oil with lowered cholesterol can be directly used as food ingredient and also for neutraceutical purpose.     

An Atomistic Understanding of Allosteric Inhibition of Glutamate Racemase: a Dampening of Native Activation Dynamics

Glutamate racemases (GR) are members of the family of bacterial enzymes known as cofactor-independent racemases and epimerases and catalyze the stereoinversion of glutamate. D-amino acids are universally important for the proper construction of viable bacterial cell walls, and thus have been repeatedly validated as attractive targets for novel antimicrobial drug design. Significant aspects of the mechanism of this challenging stereoinversion remain unknown. The current study employs a combination of MD and QM/MM computational approaches to show that the GR from H. pylori must proceed via a pre-activation step, which is dependent on the enzyme's flexibility. This mechanism is starkly different from previously proposed mechanisms. These findings have immediate pharmaceutical relevance, as the H. pylori GR enzyme is a very attractive allosteric drug target. The results presented in this study offer a distinctly novel understanding of how AstraZeneca's lead series of inhibitors cripple the H. pylori GR's native motions, via prevention of this critical chemical pre-activation step. Our experimental studies, using SPR, fluorescence and NMR WaterLOGSY, show that H. pylori GR is not inhibited by the uncompetitive mechanism originally put forward by Lundqvist et al.. The current study supports a deep connection between native enzyme motions and chemical reactivity, which has strong relevance to the field of allosteric drug discovery.     

不同菌材栽培糙皮侧耳营养品质综合评价

摘 要：目的 分析不同菌材栽培糙皮侧耳(Pleurotus ostreatus)生长及营养品质差异,并对其营养品质进行综合评价。方法 以贵州5种常见菌材锥栗(Castanea henryi)、构树(Broussonetia papyrifera)、刺槐(Robinia pseudoacacia)、光皮桦(Betula luminifera)、青冈(Quercus glauca)为主要培养料栽培糙皮侧耳,对糙皮侧耳菌丝生长、子实体主要农艺性状及营养品质进行分析。结果 糙皮侧耳在光皮桦培养基上菌丝生长速率更快,在锥栗和刺槐栽培基质中子实体主要农艺性状更好。刺槐栽培基质中糙皮侧耳子实体粗蛋白、Cu、Zn、K元素含量最高,锥栗栽培基质中糙皮侧耳子实体多糖、Na、Mg、Fe、Ca元素含量最高。以5种菌材栽培的糙皮侧耳子实体总氨基酸、必需氨基酸及总药用氨基酸均为刺槐>青冈>光皮桦>构树>锥栗。5种菌材栽培的糙皮侧耳子实体呈味氨基酸主要为甜味和苦味氨基酸,其中以光皮桦栽培的糙皮侧耳子实体鲜味和甜味氨基酸含量最高。必需氨基酸营养品质评价及营养品质综合评价结果表明刺槐栽培糙皮侧耳子实体综合营养品质更好。Fe、苏氨酸、丙氨酸、谷氨酸、精氨酸、天冬氨酸、组氨酸、Zn和多糖是5种菌材栽培的糙皮侧耳子实体主要差异营养成分。相关性分析结果显示菌材营养成分主要与糙皮侧耳菌丝生长、子实体主要农艺性状和矿物质元素含量显著相关。结论 不同营养成分的菌材对糙皮侧耳子实体生长和营养品质的影响不同,刺槐更适合作为生产糙皮侧耳主栽菌材。     

Fatty Acids,CD36, Thrombospondin-1, and CD47 in Glioblastoma: Together and/or Separately?

Glioblastoma (GBM) is one of the most aggressive tumors of the central nervous system, characterized by a wide range of inter- and intratumor heterogeneity. Accumulation of fatty acids (FA) metabolites was associated with a low survival rate in high-grade glioma patients. The diversity of brain lipids, especially polyunsaturated fatty acids (PUFAs), is greater than in all other organs and several classes of proteins, such as FA transport proteins (FATPs), and FA translocases are considered principal candidates for PUFAs transport through BBB and delivery of PUFAs to brain cells. Among these, the CD36 FA translocase promotes long-chain FA uptake as well as oxidated lipoproteins. Moreover, CD36 binds and recognizes thrombospondin-1 (TSP-1), an extracellular matrix protein that was shown to play a multifaceted role in cancer as part of the tumor microenvironment. Effects on tumor cells are mediated by TSP-1 through the interaction with CD36 as well as CD47, a member of the immunoglobulin superfamily. TSP-1/CD47 interactions have an important role in the modulation of glioma cell invasion and angiogenesis in GBM. Separately, FA, the two membrane receptors CD36, CD47, and their joint ligand TSP-1 all play a part in GBM pathogenesis. The last research has put in light their interconnection/interrelationship in order to exert a cumulative effect in the modulation of the GBM molecular network.     

Metabolic Syndrome and β-Oxidation of Long-Chain Fatty Acids in the Brain,Heart, and Kidney Mitochondria

We present evidence that metabolic syndrome (MetS) represents the postreproductive stage of the human postembryonic ontogenesis. Accordingly, the genes governing this stage experience relatively weak evolutionary selection pressure, thus representing the metabolic phenotype of distant ancestors with β-oxidation of long-chain fatty acids (FAs) as the primary energy source. Mitochondria oxidize at high-rate FAs only when succinate, glutamate, or pyruvate are present. The heart and brain mitochondria work at a wide range of functional loads and possess an intrinsic inhibition of complex II to prevent oxidative stress at periods of low functional activity. Kidney mitochondria constantly work at a high rate and lack inhibition of complex II. We suggest that in people with MetS, oxidative stress is the central mechanism of the heart and brain pathologies. Oxidative stress is a secondary pathogenetic mechanism in the kidney, while the primary mechanisms are kidney hypoxia caused by persistent hyperglycemia and hypertension. Current evidence suggests that most of the nongenetic pathologies associated with MetS originate from the inconsistencies between the metabolic phenotype acquired after the transition to the postreproductive stage and excessive consumption of food rich in carbohydrates and a sedentary lifestyle.