Synthesis and assay of antibacterial, antifungal properties of some bromo- and nitrosalicylamidorhodanine derivatives:
Analysis ; Esterification ; Anti-Bacterial Agents ; Antifungal Agents

Riboflavine tetrabutyrate is a fat soluble riboflavine derivative. It was synthesized by esterification of riboflavine with fatty acid chloride or by esterification of riboflavine with fatty acid anbydride. The advantage of riboflavine tetrabutyrate is prolongation of its biologic half life and as a result enhancing effectivity of riboflavine, This riboflavine tetrabutyrate has been used for treatment of various dermatoses of which Pathogenesis are believed to be related with abnorma1 Iipid rnetabolism. Receatty, there were many case reports showing markedly improved clinical synptoms ofpsoriatic patients who had been administered oral riboflavine tetrabutyrate for more than one month in Japan. In this clinical trial, we have also experienced effectiveness in 4 of 7 psoriatic pztients who was given oral riboflavine t trabutyrate for more than 3 months.
Esterification ; Half-Life ; Humans ; Japan ; Psoriasis* ; Riboflavin* ; Skin Diseases

This study was designed to prospect the 'In-labelled paclitaxel as tumor imaging agent. In order to provide a taxol molecule with a functional group which is able to chelate In-lll, taxol-DTPA conjugate and 2-hemisuccinyltaxol were synthesized by esterification of taxol at C-2 on C-13 carbon with DTPA anhydride and succinic anhydride, respectively. Synthesis yield of the taxol derivatives was 34% for taxol- DTPA and 80% for 2'-hemisuccinyltaxol. Cytotoxicity of the taxol derivatives were measured by MTT method toward cell lines HT29, B16, P388, and CT26. The cytotoxic activities of the taxol derivatives were maintained, although less active than taxol. Radiolabelling of the taxol derivatives were proceeded directly with 111InCh or indirectly with 111In-citrate(ligand-exchange method). The ligand-exchane methocl was not suitable because some precipitat:es appeared during the reaction. On the contrary, by direct radiolabelling methnd, we were able to obtain taxol DTPA-111In in 100% radiochemical yield. However, 2'-hemisuccinyltaxol was not labellecl by both methods. Yield and radiochemiral purity of the radiolabelled com- pound were determined by HPI.C, paper chromatography and instant thin layer chromatography. Taxol-DTPA-111In was characterized to be hydrophilic by lipophi- licity test, and nearly non-adhesive to HT29, E316, P388, and CT26 by cell hinding affinity test. Binding affinity of the taxol-DTPA-111In complex to serum proteins was also examined by protein precipitation with 30% trichloroacetic acid. The results showed that 309o of the taxol-DTPA-111In complex binds with serum proteins.
Blood Proteins ; Carbon ; Cell Line ; Chromatography, Paper ; Chromatography, Thin Layer ; Esterification ; Paclitaxel* ; Pentetic Acid ; Trichloroacetic Acid

Biodiesel, an alternative diesel fuel, fatty acid alkyl ester, is made from renewable biological sources such as vegetable oils and animal fats. Two processes for biodiesel synthesis, enzymatic lipase catalytic esterification from fatty acid and transesterification from oils and fats, was investigated. The effects of various lipases, enzyme amount and purity, solvent, water absorbent, inhibition of short chains alcohol, specificity of substrate, molar ratio of substrate on esterification were studied in detail. The esterification degree with the optimal parameter and process can reach up to 92%. The purity of biodiesel obtained by separation and purification is up to 98%, and the half-life of the immobilized lipase for the esterification process can be up to 360hr, Moreover, the preliminary studies of the transesterification including the amount of methanol and mode of adding methanol into reaction system were made. The transesterification degree with adding methanol stepwise can reach 83%.
Biofuels ; Enzymes, Immobilized ; metabolism ; Esterification ; Lipase ; metabolism ; Methanol ; metabolism ; Plant Oils ; metabolism

Biodiesel fuel produced with the enzyme-catalyzed esterification and transesterification of high acid value waste oil through ultrasonic assistant was explored. Propyl oleate, biodiesel, converted from high acid value waste oil and 1-proponal catalyzed with immobilized lipases from Candida antarctica and Aspergillus oryzae in conditions of ultrasonic assistant. Commercial immobilized lipase Novozym 435 from C. antarctica was used as biocatalyst catalyzing high acid value waste oil and 1-proponal esterification and transesterification to propyl oleate under the ultrasonic assistant conditions and different conditions such as lipases amounts, initiatory molar ratio of propanol to oil, frequency of ultrasonic and power of ultrasonic were investigated and optimized. It is revealed that the enzymatic activity of Novozym435 is enhanced and, in particular, enzyme-catalyzed transesterification activity is enhanced obviously under the ultrasonic assistant conditions. Low frequency and mild energy ultrasonic is a key factor for enhancing enzymatic activity, emulsifying oil-propanol system and accelerating the speed of produce diffusing in the system. Under the optimal ultrasonic assistant reaction conditions, such as Novozym435 amounts 8% by oil quantity, initiatory molar ratio of propanol to oil 3:1, frequency of ultrasonic 28 KHz, power of ultrasonic 100 W and temperature of water batch 40-45 degrees C, the conversion ratio to propyl oleate reached to 94.86% in 50 mins in comparison with the highest conversion ratio to propyl oleate 84.43% under the conventional mechanical agitation conditions. Furthermore, it is demonstrated that various short chain linear and branched alcohols (C1-C5) show high conversion ratio to fatty acid alkyl esters (biodiesel) under the optimal ultrasonic assistant reaction conditions. On the other hand, ultrasonic energy is propitious to reduce the adsorption of product propyl oleate, by-product glycerol and other emplastics in system on the surface of immobilized lipase Novzym435 and recyclable Novozym435 possess clean appearances, well decentralizations, no agglomeration and easy washing and well operational stability.
Bioelectric Energy Sources ; Catalysis ; Esterification ; Gasoline ; Lipase ; chemistry ; Ultrasonics ; Waste Disposal, Fluid ; methods

Policosanol extracted from sugarcane wax is a generic term used for total fatty alcohols obtained from esterification of fatty acids. It has been approved as a health functional food by the Ministry of Food and Drug Safety of Korea in 2006. Policosanol is well-known to aid in lowering blood cholesterol level. Recently, several studies have reported the physiological activities of policosanol, such as anti-inflammatory effects, antioxidant effects, and lowering of the incidence of ageing-related diseases, for example, hypertension, stroke, among others. This review describes the physiological activities of policosanol and its applications in the field of health functional foods.
Antioxidants ; Cholesterol ; Esterification ; Fatty Acids ; Fatty Alcohols ; Functional Food ; Hypertension ; Incidence ; Korea ; Saccharum ; Stroke

Adipose tissue, where various metabolic hormones are secreted, plays a role in metabolizing different substances including androgen. Within fat tissue, enzymes such as aromatase and aldo-keto reductase 1C are responsible for metabolizing testosterone into estrogen and 5-dihydrotestosterone into inactive metabolites. Adipose tissue can also affect the secretion of gonadotropin, which influences the formation of androgen in the testes. At the same time, androgen has an impact on the distribution and proliferation of adipose tissue. The adrenoreceptors for catecholamines, which have been proven to play an essential role in controlling lipolysis, function by being up-regulated by androgens. Furthermore, androgens regulate the activity of lipoprotein lipase, a key enzyme involved in intracellular esterification of adipose tissue.
Adipose Tissue ; Alcohol Oxidoreductases ; Androgens ; Aromatase ; Catecholamines ; Esterification ; Estrogens ; Gonadotropins ; Humans ; Lipolysis ; Lipoprotein Lipase ; Male ; Oxidoreductases ; Testis ; Testosterone

This paper reports the progress of biodiesel production with enzymatic catalysis in Beijing University of Chemical Technology, one of the leaders in biodiesel R & D in China, which includes screening of high-yield lipase production strains, optimization and scale-up of the lipase fermentation process, lipase immobilization, bioreactor development and scale-up, biodiesel separation and purification and the by-product glycerol utilization. Firstly, lipase fermentation was carried out at industrial scale with the 5 m3 stirred tank bioreactor, and the enzyme activity as high as 8 000 IU/mL was achieved by the species Candida sp. 99-125. Then, the lipase was purified and immobilized on textile membranes. Furthermore, biodiesel production was performed in the 5 m3 stirred tank bioreactor with an enzyme dosage as low as 0.42%, and biodiesel that met the German biodiesel standard was produced. And in the meantime, the byproduct glycerol was used for the production of 1,3-propanediol to partly offset the production cost of biodiesel, and 76.1 g/L 1,3-propanediol was obtained in 30 L fermentor with the species Klebsiella pneumoniae.
Biofuels ; Bioreactors ; Biotechnology ; economics ; methods ; Candida ; enzymology ; Catalysis ; China ; Enzymes, Immobilized ; metabolism ; Esterification ; Fermentation ; Lipase ; metabolism ; Plant Oils ; chemistry

The asialoglycoprotein receptor (ASGPR) was used to mediate drug carrier for hepatic targeted drug delivery, this article showed the enzyme-catalyzed esterification of galactose and vinyl stearate and a kind of ASGPR ligand-targeted which was used to insert the surface of liposome has been synthesized. The structure of product has been confirmed by TLC, ESI-MS and 1H NMR. The factors of types and quantity of enzyme, organic solvents, molar ratio of substrate, temperature and time of reaction have been studied. Results showed when using acetone as reaction medium, the quantity of Novozym 435 immobilized lipase was 30 mg mL(-1), molar ratio of galactose to vinyl stearate was 1:5, and reacted at 60 degrees C for 12 h, the transformation of vinyl stearate reached more than 70%. This study provides a novel and efficient route to the synthesis of ligand-targeted modifier.
Acetone ; chemistry ; Asialoglycoprotein Receptor ; chemical synthesis ; Catalysis ; Esterification ; Galactose ; chemistry ; Ligands ; Lipase ; chemistry ; Stearates ; chemistry ; Temperature ; Vinyl Compounds ; chemistry

Gatifloxacin (GFX) is a kind of chiral fluoroquinolones compound due to the methyl group at the C-3 position of the piperazine ring[1]. Although the enantiomers of GFX show similar levels of antimicrobial activity and pharmacokinetics[2], the other biological activities (i.e., toxicity or enantioselective recognition to various receptors in vivo) of GFX enantiomers have not yet been studied. With this in mind, we developed a rapid and cost-effective high performance liquid chromatographic (HPLC) separation procedure for GFX enantiomers with a pre-column esterification strategy. With significant enhancement of drug solubility and optimization for chromatographic conditions, the proposed method was scaled up to preparative HPLC to obtain optical active S-(-)- and R-(+)-GFX. The antibacterial activities of GFX enantiomers after preparative separation were further verified by measuring the Minimum Inhibitory Concentration (MIC) values against Escherichia coli ATCC 25922. In addition, the binding selectivity of GFX enantiomers to protein receptor were evaluated by antibody using enzyme-linked immunosorbent assay (ELISA) for the first time.
Anti-Bacterial Agents ; chemistry ; pharmacology ; Escherichia coli ; drug effects ; Esterification ; Fluoroquinolones ; chemistry ; pharmacology ; Microbial Sensitivity Tests ; Molecular Structure ; Structure-Activity Relationship