Riboflavin (vitamin B2) is an indispensable nutrient for humans and animals, since it is the precursor of the essential coenzymes flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), involved in variety of metabolic reactions. Riboflavin is produced on commercial scale and is used for feed and food fortification purposes, and in medicine. Until recently, the mutant strains of the flavinogenic yeast Candida famata were used in industry for riboflavin production. Guanosine triphosphate is the immediate precursor of riboflavin synthesis. Therefore, the activation of metabolic flux toward purine nucleotide biosynthesis is a promising approach to improve riboflavin production. The phosphoribosyl pyrophosphate synthetase and phosphoribosyl pyrophosphate amidotransferase are the rate limiting enzymes in purine biosynthesis. Corresponding genes PRS3 and ADE4 from yeast Debaryomyces hansenii are modified to avoid feedback inhibition and cooverexpressed on the background of a previously constructed riboflavin overproducing strain of C. famata. Constructed strain accumulates twofold more riboflavin when compared to the parental strain.

the effect of long-term oral taurine administration to rats on activity of lactate dehydrogenase (LDH), its isozyme content and activity in the whole blood, liver, thigh muscle, brain and testes tissues were studied in the present work. For this purpose male Wistar rats with body weight 190-220 g were randomly divided into three groups, they were orally administered drinking water (control group) or taurine solution 40 and 100 mg per kg of body weight ( groups I and II, respectively). the total lactate dehydrogenase activity was measured spectrophotometrically, the percentage content of isozymes was determined by electrophoresis in 7.5% poliacrylamide gel with further staining according to J. glucose metabolism in the organism and, possibly, regulate the activity of enzymes associated with glycolysis. Adding taurine to neurons previously incubated with MPP + , a substance that causes neurons degeneration, lead to increased lactate dehydrogenase activity and ATP re-synthesis [7]. Garbus. It was found that the total lactate dehydrogenase activity increased in all studied tissues. In testes of animals of both groups and in brain of group I animals, the total percentage contents of isozymes that are responsible for lactate production (LDH4+LDH5) increased. In liver of animals of both groups and in whole blood of group II animals, the total percentage content of isozymes that produce pyruvate (LDH1+LDH2) increased. In thigh muscle of both groups and in brain of group II animals the balance between LDH1+LDH2 and LDH4+LDH5 content did not differ fromSince lactate dehydrogenase is one of the markers of metabolic functional stability, the aim of the study was to investigate the effect of long-term oral administration of taurine on the total lactate dehydrogenase enzyme activity and the content of its isozymes in different rat tissues. materials and methodsMale Wistar rats were used in the experiments. The rats were 4.5 months old and had body weight of 190-220 g at the beginning of the experiment. Animal experiment was performed in accordance with European Convention for the Protection of Vertebrate Animals used for Experimental and Other Scientific Purposes and the law of Ukraine On the protection of animals against Cruel treatment. Animals were randomly assigned to three groups: one control group and two experimental groups. Over a 28 day period, the animals were daily administered in the esophagus with: control groupdrin king water, group I -solution of taurine 40 mg/ kg, group II -solution of taurine 100 mg/kg. First dose was selected because it induced recovery of the nervous system in mice after administration of ethanol per os [8]. Second dose is one fiftieth of LD 50 and often used in studies of taurine detoxication effects [9][10][11]. The animals were decapitated on the 29 th day under light chloroform anesthesia and blood was collected in a tube with heparin. Liver, brain, testis and thigh muscle were isolated. After blood sampling, the number of erythrocytes was determined by colorimetry at 670 nm [12]. The h...

Simple, fast, and validated UV-spectrophotometric, HPLC, and GC methods for the analysis of benzalkonium chloride in a disinfectant were developed. UV-spectrophotometric determination was based on measuring the amount of light absorption of aqueous solutions of benzalkonium chloride at 268 nm. HPLC determination was achieved with a 150 mm × 4.6 mm, 5.0 μm C18 column. The mobile phase consisted of a 0.01% water solution of triethylamine (with pH 2.5) and acetonitrile in the ratio of 40 : 60 v/v. The column temperature was kept at 30°C, and the injection volume was 10 μL. The flow rate was 1.0 mL/min, and the diode array detector was set at 215 nm. GC determination was performed using a flame ionization detector on a glass capillary column ZB-WAX plus 30 m × 0.25 mm with an inner coating thickness of 0.25 μm. It creates a gradient increase in the temperature of the furnace to the maximum of 200°C. The temperature of the injector was 250°C, 1 μl was injected, and the separation of the sample was 1 : 100. Helium was used as a carrier gas, and the gas flow rate was constant, equaling 1.6 ml/min. The temperature of the detector was 250°C, and a mixture of hydrogen, helium, and air in a ratio of 30 : 8.5 : 350 was used in the split of the detector. All proposed methods were validated according to ICH guidelines with respect to the accuracy, precision (interday, intraday, and reproducibility), linearity, the limit of detection, the limit of quantitation, and robustness. All three methods were linear (R2 = 0.997–0.999) over a concentration range of 400–600 μg/ml for UV and 80–120 μg/ml for HPLC and GC, accurate (recovery was 98.4–101.7% for all methods), precise (RSD <2%), and robust. The cost of the analysis of one sample of the disinfectant for the content of benzalkonium chloride by three methods was calculated. The comparison of the obtained results facilitates a more efficient allocation of laboratory resources, depending on the goal.

Aim of this work was to study the activity of antioxidant defense enzymatic link, glucose-6-phosphate dehydrogenase activity and content of TBA-active products at long term per oral injection of taurine. Male Wistar rats (4.5 months old and with body weight 190-220 g) were used in the experiments. Animals were randomly divided into three groups: one control group and two experimental groups. During 28 days period, animals were daily injected in esophagus: control group-drinking water, experimental group I and II-solution of taurine (40 and 100 mg/kg of body weight, respectively). On the 29 th day, the animals were decapitated under light chloroform anesthesia, and liver, brain, testes and thigh muscle were extirpated. The tissues were homogenized and then centrifuged for 15 min at 1,000 g. In supernatant, the activities of superoxide dismutase, glutathione peroxidase, catalase and glucose-6-phosphate dehydrogenase, and content of TBA-active products were measured. Ratio of antioxidant enzymes activity to TBA-active products content (AOD/TBA) was calculated. It was determined, that in rat liver of I st experimental group, the activity of all antioxidant defense enzymes, glucose-6-phosphate dehydrogenase and content of TBA-active products increased. Under these conditions, the resistance of this tissue to oxygen free radicals, and AOD/ TBA ratio also increases. In the II nd experimental group, the superoxide dismutase activity was similar to control values, but other indices remained higher than in control group. Similar trend was observed in the thigh muscle of both experimental groups, where it was found that, activity of antioxidant enzymes and glucose-6-phosphate dehydrogenase increased, and the amount of lipid peroxidation products also elevated. At the same time, the AOD/TBA ratio was the highest in animals of the II nd experimental group. In testes of animals of the І ts experimental group, an increase in the glutathione peroxidase activity was established, and the content of TBA-active products was the highest among three groups. A rise in content of TBA-active products caused a decrease in AOD/TBA ratio in more than 4 times. In the II nd experimental group, it was found that the increase of antioxidant enzymatic activity and decrease of content of TBA-active products, compared to the I st experimental group, caused an increase in AOD/TBA ratio. In brain tissue, glutathione peroxidase and catalase activity increased at a constant content of peroxidation products. This caused an increase in AOD/TBA ratio, that indicates growth

Досліджували вплив тривалого перорального введення таурину на інтенсивність дихання мітохондрій та окисне фосфорилювання у тканинах печінки, головного мозку, сім'яників і стегнового м'яза щурів. Для цього самців щурів лінії Вістар масою 190-220 г розділили на три дослідні групи, яким щоденно протягом 28 діб вводили питну воду (контрольна група) або розчин таурину у розрахунку 40 чи 100 мг / кг (І та ІІ дослідні групи відповідно). Швидкість дихання визначали полярографічно з використанням електрода Кларка під час окиснення ендогенних субстратів (V 1), за додавання екзогенних α-кетоглутарату (5 ммоль/л) або сукцинату (1 ммоль/л; V S 4), коли додавали АДФ до кінцевої концентрації 200 мкмоль/л (V 3) та після використання АДФ мітохондріями (V 4 АТФ). З'ясувалося, що за тривалого введення таурину V 1 зросла у тварин обох дослідних груп у печінці та мозку на 50-60%, проте знижувалась у сім'яниках та м'язах І дослідної групи на 48-73%. У печінці тварин І дослідної групи як за окиснення α-кетоглутарату, так і сукцинату V S 4 , V 3 , та V 4 АТФ були у 4-7 разів вищими за контроль. У печінці тварин ІІ дослідної групи за окиснення α-кетоглутарату ці показники були вищими на 57-126 %. У м'язах І дослідної групи у разі додавання α-кетоглутарату і сукцинату V S 4 , V 3 , та V 4 АТФ були нижчими на 41,4-60,9 %, у м'язах тварин ІІ дослідної групи під час окиснення α-кетоглутарату V 3 була на 23,7 % вища. При додаванні сукцинату V S 4 , та V 4 АТФ зросли на 31-70 % у сім'яниках тварин обох дослідних груп та у мозку І дослідної групи. Однак у мозку тварин ІІ дослідної групи інтенсивність дихання V S 4 була на 38,3 % нижчою. Отже, вплив тривалого введення таурину на інтенсивність споживання кисню мітохондріями є дозозалежним і тканиноспецифічним і, вочевидь, має різне значення та реалізується різними механізмами. Ключові слова: таурин; інтенсивність дихання мітохондрій; окисне фосфорилювання; печінка; мозок; сім'яники; стегновий м'яз.