Macrophage-targeting oligopeptides from Mortierella alpina

The realm of natural products of early diverging fungi such as Mortierella species is largely unexplored. Herein, the nonribosomal peptide synthetase (NRPS) MalA catalysing the biosynthesis of the surface-active biosurfactants, malpinins, has been identified and biochemically characterised. The investigation of the substrate specificity of respective adenylation (A) domains indicated a substrate-tolerant enzyme with an unusual, inactive C-terminal NRPS module. Specificity-based precursor-directed biosynthesis yielded 20 new congeners produced by a single enzyme. Moreover, MalA incorporates artificial, click-functionalised amino acids which allowed postbiosynthetic coupling to a fluorophore. The fluorescent malpinin conjugate penetrates mammalian cell membranes via an phagocytosis-mediated mechanism, suggesting Mortierella oligopeptides as carrier peptides for directed cell targeting. The current study demonstrates substrate-specificity testing as a powerful tool to identify flexible NRPS modules and highlights basal fungi as reservoir for chemically tractable compounds in pharmaceutical applications.

Specificity profiling of a nonribosomal peptide synthetase of an early diverging fungus revealed high substrate flexibility. Feeding studies with click-functionalised amino acids enabled the production of fluorescent peptides targeting macrophages.     

Development of a Defined Medium for Arachidonic Acid Production by Mortierella alpina Using a Visualization Method

Defined medium for arachidonic acid (ARA) production by Mortierella alpina was optimized for its metabolomics study. For this purpose, a visualization method (VM) was applied for the first time. Experiments were designed according to the uniform design with four factors (concentrations of glucose, NaNO₃, KH₂PO₄ and MgSO₄·7H₂O) for each at nine levels. Dry cell weight (DCW), ARA yield in DCW [percent (w/w)] and ARA content in total fatty acids [percent (w/w)] were considered as the three objectives. Optimization of single-objective function and multi-objective function of two objectives and three objectives was attempted. Optimal DCW, ARA yield and ARA content were predicted to occur in a medium that contained (grams per litre): glucose 35, NaNO₃ 1, KH₂PO₄ 7.5 and MgSO₄·7H₂O 2.6. Upon verification, the average tested DCW (12.95?g/l), ARA yield (18.89?%) and ARA content (42.36?%) were fairly close to the predicted values (12.88?g/l, 9.68?% and 35.57?%, respectively). Moreover, DCW, ARA yield and ARA content from the optimum medium increased by 35.68, 47.23 and 30.90?% compared with control, respectively, indicating that VM had succeeded in exploiting the biomass growth and ARA production by M. alpina.     

Liquid Chromatographic Separation of Some Common Benzodiazepines and their Metabolites

Abstract

A series of benzodiazepines commonly encountered in forensic samples were separated using isocratic reversed-phase liquid chromatography. These compounds display a wide range of capacity factors on a C₁₈ stationary phase in a pH 8 phosphate buffer and methanol mobile phase. Clorazepate must be analyzed under basic mobile phase conditions to prevent its decomposition to N-desmethyldiazepam. The separation of common parent benzodiazepines such as chlordiazepoxide, diazepam and flurazepam from their corresponding metabolites was achieved under a variety of reversed-phase conditions.     

Structural Investigation of Betulinic Acid Plasma Metabolites by Tandem Mass Spectrometry

Betulinic acid (BA) has been extensively studied in recent years mainly for its antiproliferative and antitumor effect in various types of cancers. Limited data are available regarding the pharmacokinetic profile of BA, particularly its metabolic transformation in vivo. In this study, we present the screening and structural investigations by ESI Orbitrap MS in the negative ion mode and CID MS/MS of phase I and phase II metabolites detected in mouse plasma after the intraperitoneal administration of a nanoemulsion containing BA in SKH 1 female mice. Obtained results indicate that the main phase I metabolic reactions that BA undergoes are monohydroxylation, dihydroxylation, oxidation and hydrogenation, while phase II reactions involved sulfation, glucuronidation and methylation. The fragmentation pathway for BA and its plasma metabolites were elucidated by sequencing of the precursor ions by CID MS MS experiments.     

Separation of Twelve Catecholamine Metabolites and Determination of Some of the Metabolites in Human Urine by Liquid Chromatography with Electrochemical Detection

Abstract

Separation of twelve catecholamine metabolites on a reversed-phase column was achieved, when eluate from the column was amperometrically monitored at +800 mV vs. Ag/AgCl. The mobile phase was a 0.1 M acetate buffer (pH 5.0). The flow rate and column temperature were 1.5 ml/min and 25 ± 1°C, respectively. Ethyl acetate extraction of the catecholamine metabolites from acidified human urine was studied and optimized. We demonstrate the feasibility of the method showing some liquid chromatographic results.     

深黄被孢霉生物转化十六醇合成油脂的研究

不饱和脂肪酸有重要的生理机能 ,寻找富含不饱和脂肪酸的新油源 ,以弥补动植物油源的不足已成为当前的研究热点 .高碳醇转化为高碳酸已有报道[1],但将其转化为不饱和脂肪酸的研究还少见报道 .利用产脂微生物合成不饱和脂肪酸是开发新油源的良好途径[2 ,3].本文用深黄被孢霉生物转化十六醇合成油脂 ,并分析了油脂中脂肪酸的组成 ,对转化条件也进行了初步研究 .1　实验部分将深黄被孢霉 (Ｍｏｒｔｉｅｒｅｌｌａｉｓａｂｅｌｌｉｎａ)于 2 8℃在种子培养液中活化 2 4ｈ ,然后接种于十六醇转化培养基上 ,于 2 8℃摇瓶发酵 96ｈ(摇瓶转速 1 50ｒ…     

液相色谱-四极杆/静电场轨道阱高分辨质谱鉴定一种新精神活性物质5F-MDMB-PICA在斑马鱼体内的代谢产物

通过建立斑马鱼模型研究5F-MDMB-PICA(3,3-二甲基-2-[1-(5-氟戊基)吲哚-3-甲酰氨基]丁酸甲酯)的体内代谢转化途径,利用液相色谱-四极杆/静电场轨道阱质谱(LC-Q-Orbitrap MS)技术,结合Mass Frontier软件对5F-MDMB-PICA及其代谢产物进行质谱解析和结构分析.结果表...     

Quantum Yields of Singlet-Oxygen Production by Some Natural Quinoid Fungal Metabolites and Derivatives

Perylene quinone compounds of natural and syntheitc origin have been investigated for their quantum efficiency of singlet-oxygen production (Φ_Δ). The results may be interpreted by a qualitative relation between Φ_Δ and the planarity of the sensitizer molecules, highest values (0.8–0.9) being observed where planarity is favoring tautomeric structures. On the other hand, derivatives exhibiting non-planar quinoid structures show lower Φ_Δ, and methylated derivatives react photochemically.     

Comparison of Some Secondary Metabolites in Cotton Leaves That Differ in Genetic Markers

The change in the content of sterols, tocopherols, and polyprenols during three phases of cotton ontogenesis that differ in genetic markers was studied. The content of these components of self-marking strains and their parental varieties is compared     

深黄被孢霉催化转化脂肪醇合成不饱和脂肪酸的初步研究

The unsaturated fatty acids were biosynthesized by Mortierella isabellina grown on fatty alcohols (butanol, hexadecanol, octadecanol, etc) at 28 ℃ for 5 d and the fatty acid composition was analyzed by gas chromatography. The results showed that more lipid and higher content of the corresponding unsaturated fatty acids could be biosynthesized by the fungi grown on the long chain alcohols. Meanwhile, long chain alcohols were converted more quickly and had higher conversion. It suggests that long chain alcohols are more practical substrates.     

Investigation on Oxidation-Reduction Properties of Some Fe-S and Mo-Fe-S Clusters

Oxidation-reduction properties of some Fe-S and Mo-Fe-S clusters have been studied by cyclic voltammetric measurement. It is indicated that there are some factors which affect the oxidation- reduction properties of clusters, of which are charge density of metal atom in cluster core, electron effect of ligands, charge and geometric configurations of the reactant particle, etc.     

气相色谱化学电离二级质谱法对玉米籽粒中三嗪类除草剂及其代谢物的测定

建立了玉米籽粒中三嗪类除草剂及其代谢物残留的气相色谱化学电离二级质谱(GC-CI MS/MS)分析方法.样品采用盐酸和乙腈混合溶液均质提取,石墨化碳黑(GCB)与中性氧化铝的混合固相萃取柱净化,GC-CI MS/MS基质外标法测定.三嗪类除草剂及代谢物在0.05(0.10) ～4.0 mg/L范围内线性良好,相关系数r在0.993 9以上(脱乙基莠去津溶剂标准曲线的r=0.989 4);在0.050、0.100 μg/g添加水平,平均添加回收率为72% ～108%,相对标准偏差为3.09% ～20.14%,满足进出口及残留监控测定的需要.     

High-Pressure Liquid Chromatographic Separation of Diphenhydramine and Some of its Metabolites: Effects of Eluent Salt Concentration on Chromatographic Characteristics

Abstract

With appropriate variation of the pH, alkali halogenide concentration and cation and/or anion species in the mobile phase (mixtures of water and methanol), it was possible to resolve diphenhydramine, N-desmethyldiphenhydramine, N,N-didesmethyldiphenhydramine, benzhydrol, benzophenone and 2-methyldiphenylmethoxy acetic acid on a reversed-phase column. The retention volumes of the three amines decreased by increasing the following parameters: salt concentration, methanol concentration and cation and/or anion size. The retention volumes of the other compounds were not influenced. The good separation and the simplicity make this method attractive for use in metabolism studies.     

反应条件对深黄被孢霉催化转化十六醇合成不饱和脂肪酶的影响

 研究了深黄被孢霉催化转化十六醇合成不饱和脂肪酸过程中反应条件对底物转化率及产物选择性的影响．结果表明,亚油酸的选择性随十六醇与酵母膏比例（碳氮比）的增大而升高,亚麻酸的选择性随碳氮比的增大而降低,油脂的选择性和油脂的产率随碳氮比的变化规律相似．十六醇浓度为0．5％时,油脂的选择性、产率及醇的转化率最高,亚油酸和亚麻酸的选择性也最高．油脂的选择性和产率在pH＝7时较高,而醇的转化率随pH升高而降低,亚油酸和亚麻酸的选择性在pH＝6时分别达到最大值．油脂的选择性、产率和醇的转化率在23～28℃达到较高水平,亚油酸和亚麻酸的选择性在23℃达到最大值．油酸的选择性对油脂的选择性有重要影响,二者的变化规律相似．     

Ultrasound as a Promising Tool for the Green Extraction of Specialized Metabolites from Some Culinary Spices

Spices are a popular food of plant origin, rich in various phytochemicals and recognized for their numerous properties. The aim of the study was to evaluate the antioxidant and antimicrobial activity, as well as the content of specialized metabolites, of aqueous extracts of three spice species––garlic (Allium sativum L.), ginger (Zingiber officinalle L.) and turmeric (Curcuma longa L.)––prepared by green extraction methods. Ultrasound treatment increased the chromaticity parameter b value of turmeric and ginger extracts, thus indicating a higher yellow color predominantly due to curcuminoids characteristic of these species. Ultrasound-assisted extraction significantly increased the content of total soluble solids, phenolic compounds, total carotenoids and vitamin C. The temperature of the system was also an important factor, with the highest (70 °C) conditions in ultrasound-assisted extraction having a positive effect on thermolabile compounds (vitamin C, phenolics, total carotenoids). For example, turmeric extract treated with ultrasound at 70 °C had up to a 67% higher vitamin C content and a 69.4% higher total carotenoid content compared to samples treated conventionally at the same temperature, while ginger extracts had up to 40% higher total phenols. All different concentrations of spice extracts were not sufficient for complete inhibition of pathogenic bacterial strains of Salmonella, L. monocytogenes and S. aureus; however, only garlic extracts had an effect on slowing down the growth and number of L. monocytogenes colonies. Spice extracts obtained by ultrasonic treatment contained a significantly higher level of bioactive compounds and antioxidant capacity, suggesting that the extracts obtained have significant nutritional potential and thus a significant possibility for phytotherapeutic uses.     

Investigation of Phosphorylation of Cyclodextrins and Some their Derivatives

Abstract

Principal regularities of per- and regodirected phosphorylation of α-β-, and γ-cyclodextrins (R=R¹=R²=OH, n= 1–3) by trivalent phosphorus reagents were investigated. As a result, the first representatives of regularly organized phosphites and amidophosphites of cyclodextrins, including ones with interglucoside 2,3′-cyclophosphite bridges [R¹+R²=-P(NR₂′)-], having chiral cavities of different sizes, were obtained. Per-6-deoxy-6-bromocyclodextrins (R=Br) were considered as convenient intermediates for the synthesis of pyndinium salts with amphiphilic properties for the enhanced water-solubility and for the definite orientation at the phase boundary organic liqiud-water.     

Metabolites of fusidium coccineum

Nine cometabolites of the antibiotic fusidic acid (1a) have been identified. These include the fusidane derivatives (5a, 6a, 7a, 8a, 9a, 10a, and 12a), 7,8-dehydropseudofusidic acid (11a), and fusilactidic acid (13a).     

被孢霉菌丝体脂肪酸组成的气相色谱-质谱分析

采用气相色谱－质谱对采自云南白马雪山土壤中并经分离和发酵培养的被孢霉菌株SM96的菌丝体油脂中脂肪酸组成进行了定性分析和峰面积相对含量测定，共检测出30种脂肪酸，其中多不饱和脂肪酸含量为62．4％，主要为亚油酸、α－亚麻酸（ALA），还有少量的γ－亚麻酸、二十碳三烯酸、花生四烯酸和二十碳五烯酸（EPA）等，结果表明该菌株能产生EPA。