Polyhydroxyalkanoates (PHA) is a family of microbially synthesized polyesters consisting of various 3-hydroxyalkanoate monomers. Aeromonas hydrophila 4AK4 could be able to synthesize PHA copolymer consisting of 3-hydroxybutyrate (3-HB) and 3-hydroxyhexanoate (3-HHx). No data has been reported about the ability to synthesize the PHA with other monomers in A. hydrophila. In this study, propionic acid, valeric acid, heptanoic acid, nonanoic acid and undecanoic acid were used together with gluconate to find out whether A. hydrophila 4AK4 could synthesize the PHA consisting of odd carbon atom number monomers. The result showed that A. hydrophila 4AK4 could not growth when supplied with propionic acid, valeric acid, heptanoic acid and nonanoic acid and only undecanoic acid could be used to synthesize PHA. Wild type and recombinant A. hydrophila 4AK4 harboring phaA (beta-ketothiolase) and phaB (acetoacetyl-CoA reductase) were cultivated with undecanoic acid and glucose or undecanoic acid and gluconate served as carbon sources. PHA consisting of 3-HB and 3-hydroxyvalerate (3-HV) could be produced by both wild type and recombinant A. hydrophila 4AK4 and the latter could produce PHA with more 3-HB monomer. When the ratio of glucose or gluconate to undecanoic acid was 1:1, the cell dry weight (CDW) of A. hydrophila 4AK4 reached 1.14 g/L and PHA content was 60% of the CDW after cultivation for 24 h. When lauric acid and undecanoic acid were served as co-substrate, A. hydrophila 4AK4 could produce copolyester consisting of 3-HB, 3-HV and 3-HHx. Along with the increase of undecanoic acid proportion in the mixed carbon source, the 3-HV content of copolymer was increased while the 3-HB and 3-HHx content were decreased. In all cases, the CDW decreased along with the increase of undecanoic acid concentration, which indicated that undecanoic acid was not very good for A. hydrophila 4AK4 growth.
Aeromonas hydrophila ; metabolism ; Fatty Acids ; metabolism ; Glucose ; metabolism ; Lauric Acids ; metabolism ; Pentanoic Acids ; metabolism ; Polyhydroxyalkanoates ; biosynthesis

A hydrophobic low-density lipoprotein cholesterol (LDL-C) adsorbent was synthesized with lauric acid and chitosan. The condition for adsorption was obtained by investigating the influence of adsorbent amount and adsorption time. The results of adsorption in vitro showed that the average adsorption rates for total cholesterol (TC), LDL-C, high-density lipoprotein cholesterol (HDL-C) and total protein (TP) were 47.7%, 84.7%, 18.1% and 5.9% respectively. The adsorbent possesses good selectivity in removing LDL-C.
Adsorption ; Blood Component Removal ; methods ; Chitosan ; chemistry ; Cholesterol, LDL ; blood ; isolation & purification ; Lauric Acids ; chemistry

OBJECTIVEA new rat model of cerebral infarction was developed to elucidate the contribution of vascular endothelial cell during focal cerebral infarction formation.

METHODSForty-eight Sprague-Dawley (SD) rats were randomly divided into the model group, sham operation group, and control group for indexes observation of triphenyltetrazolium chloride (TTC) dyeing, neurological deficit, plasma tissue-type plasminogen activator (tPA) activity, plasminogen activator inhibitor (PAI) activity, thromboxane B(2) (TXB(2)) content, and 6-keto-prostaglandin (6-keto-PGF(1alpha)) content.

RESULTS(1) The highest neurological score appeared at 6 h after operation, descending significantly at sequential time. (2) Using TTC dyeing and optical microscope technique, pathological changes in brains were observed. (3) Compared with control group and sham operation groups, there was a decrease in tPA activity of model rats at the initial 12 h after injection of sodium laurate (P < 0.05), PAI activity decreased markedly in the model group at 24 h after injection of sodium laurate. (4) In plasma TXB(2) concentration reached the highest level compared at 6 h after injection of sodium laurate, but there were not obvious differences in plasma 6-keto-PGF(1alpha) concentration among all groups (P > 0.05).

CONCLUSIONFocal cerebral infarction in rats could be induced by some sodium laurate, showing ischemic cerebrum necrosis, function disorder of vascular endothelium-platelet, fibrinolysis abnormality. This model could play an important role in researching the contribution of vascular endothelial cell during cerebral infarction development, preventing and curing by traditional Chinese medicine.

Animals ; Carotid Arteries ; Cerebral Infarction ; chemically induced ; pathology ; physiopathology ; Disease Models, Animal ; Endothelial Cells ; pathology ; Lauric Acids ; administration & dosage ; Ligation ; Rats ; Rats, Sprague-Dawley

Fatty acid binding and oxidation kinetics for wild type P450(BM3) (CYP102A1) from Bacillus megaterium have been found to display chain length-dependent homotropic behavior. Laurate and 13-methyl-myristate display Michaelis-Menten behavior while there are slight deviations with myristate at low ionic strengths. Palmitate shows Michaelis-Menten kinetics and hyperbolic binding behavior in 100 mmol/L phosphate, pH 7.4, but sigmoidal kinetics (with an apparent intercept) in low ionic strength buffers and at physiological phosphate concentrations. In low ionic strength buffers both the heme domain and the full-length enzyme show complex palmitate binding behavior that indicates a minimum of four fatty acid binding sites, with high cooperativity for the binding of the fourth palmitate molecule, and the full-length enzyme showing tighter palmitate binding than the heme domain. The first flavin-to-heme electron transfer is faster for laurate, myristate and palmitate in 100 mmol/L phosphate than in 50 mmol/L Tris (pH 7.4), yet each substrate induces similar high-spin heme content. For palmitate in low phosphate buffer concentrations, the rate constant of the first electron transfer is much larger than k (cat). The results suggest that phosphate has a specific effect in promoting the first electron transfer step, and that P450(BM3) could modulate Bacillus membrane morphology and fluidity via palmitate oxidation in response to the external phosphate concentration.
Bacterial Proteins ; metabolism ; Cytochrome P-450 Enzyme System ; metabolism ; Fatty Acids ; chemistry ; metabolism ; Lauric Acids ; chemistry ; metabolism ; Myristic Acid ; chemistry ; metabolism ; NADPH-Ferrihemoprotein Reductase ; metabolism ; Osmolar Concentration ; Oxidation-Reduction ; Palmitic Acid ; chemistry ; metabolism ; Structure-Activity Relationship

Copolyesters consisting of 3-hydroxybutyrate (3HB) and 3-hydroxyhexanoate (3HHx) (PHBHHx), a new type of biodegradable material, are receiving considerable attentions recently. The material properties are strongly related to the 3HHx fraction of PHBHHx. As the 3HHx fraction increase, crystallinity and melting point of PHBHHx decrease, flexibility and tractility increase. PHBHHx of different 3HHx fraction can meet different demands of commercial application and research. Aeromonas are the best studied PHBHHx-producing strains. Recent studies have been focused on optimizations of fermentative culture media and culture conditions for low-cost and efficient fermentative production. Aliphatic substrates such as long-chain fatty acid and soybean oil were used in the PHBHHx fermentation as the sole carbon source and energy source. Two-stage fermentation method was also developed for more efficient PHBHHx production. While studies on Aeromonas hydrophila revealed that the monomer composition of PHBHHx could not easily be regulated by fermentative process engineering methods such as changing substrates and fermentative conditions because precursors involved in the PHBHHx synthesis were all from the beta-oxidation pathway. In this study, phbA gene encoding beta-ketothiolase and phbB gene encoding acetoacetyl-CoA reductase were introduced into a PHBHHx-producing strain Aeromonas hydrophila 4AK4 so as to provide a new 3HB precursors synthesis way. phbA gene encodes beta-ketothiolase which can catalyze two acetyl-CoA to form acetoacetyl-CoA; phbB gene encodes acetoacetyl-CoA reductase catalyzing acetoacetly-CoA into 3HB-CoA which is the precursor of 3HB. The introduced novel 3-hydroxybutyrate precursor synthesis pathway allowed the recombinant strain to use unrelated carbon source such as gluconate to provide 3HB precursors for PHBHHx synthesis. Shake-flask experiments were carried out to produce PHBHHx of controllable monomer composition and fermentations in 5 L fermentor were also proceeded for confirmation of these result in large-scale culture. In flask culture, it was possible to reduce the 3HHx mol fraction in PHBHHx from 15 % in the wild type to 3% - 12% in the recombinant by simply changing the ratio of gluconate to lauric acid in the culture media. When lauric acid was used as the sole carbon source, 51.5 g/L Cell Dry Weight (CDW) containing 62 % PHBHHx with 9.7 % 3HHx mol fraction was obtained in 56 hours of fermentation in a 5 liter fermentor. When co-substrates of sodium gluconate and lauric acid (1:1) were used as carbon sources, 32.8 g/L CDW containing 52 % PHBHHx with 6.7% 3HHx mol fraction was obtained in 48 hours of fermentation. These results showed the possibility for fermentative production of PHBHHx with controllable monomer composition.
3-Hydroxybutyric Acid ; metabolism ; Acetyl-CoA C-Acyltransferase ; genetics ; metabolism ; Aeromonas hydrophila ; enzymology ; genetics ; metabolism ; Alcohol Oxidoreductases ; genetics ; metabolism ; Bacterial Proteins ; genetics ; metabolism ; Biotechnology ; methods ; Caproates ; metabolism ; Fermentation ; genetics ; physiology ; Lauric Acids ; metabolism

AIMTo prepare rifapentine (RIF) liposomes modified by surfactants for studying their the water-solubility, drug loading effeciency, release rate and pulmonary drug delivery.

METHODSThe film method was used to prepare RIF liposomes. Of verious RIF liposomes morphology by lauric diethanolamide (LDEA), Tween 80 and azone, the properties were studied, envolving morphology, entrapment drug release rate and dissected lung-membrance penetration rate of swine. Pulmonary delivery study was carried out through bronchoscope.

RESULTSThe particle size of RIF-LDEA liposomes was between 15 - 50 nm. The top entrapment efficiency reached 83.0%. The apparent coefficient of membrane penetration (Kp) was 44.29. LD50 was 675 mg x kg(-1) by iv.

CONCLUSIONLDEA increased the water-solubility, loading effeciency and release rate of RIF liposomes. The prepared RIF-LDEA liposomes were suitable for the treatment of pulmonary tubrculosis through bronchoscope.

Animals ; Antibiotics, Antitubercular ; administration & dosage ; chemistry ; pharmacokinetics ; Drug Carriers ; Drug Delivery Systems ; methods ; Ethanolamines ; chemistry ; Lauric Acids ; chemistry ; Liposomes ; Lung ; metabolism ; Particle Size ; Permeability ; Rifampin ; administration & dosage ; analogs & derivatives ; chemistry ; Solubility ; Swine

To study the chemical constituents of Drynariae Rhizoma, nine phenolic acids were isolated from a 70% ethanol extract by using a combination of various chromatographic techniques including column chromatography over silica gel, ODS, Sephadex LH-20, and semi-preparative HPLC. By spectroscopic techniques including 1H NMR, 13C NMR, 2D NMR, and HR-ESI-MS, these compounds were identified as 4, 4'-dihydroxy-3, 3'-imino-di-benzoic acid (1), protocatechuic acid (2), gallic acid (3), p-hydroxybenzoic acid (4), (E)-caffeic acid (5), ethyl trans-3, 4-dihydroxycinnamate (6), caffeic acid 4-O-beta-D-glucopyranoside (7), p-coumaric acid 4-O-beta-D-glucopyranoside (8), and 23(S)-12-O-caffeoyl-12-hydroxyllauric acid glycerol ester (9), separately. Among them, 1 and 9 are new compounds, and 3, 4, and 6 were isolated from Drynaria species for the first time.
Benzoates ; chemistry ; isolation & purification ; Caffeic Acids ; chemistry ; isolation & purification ; Cinnamates ; chemistry ; isolation & purification ; Gallic Acid ; chemistry ; isolation & purification ; Glycerol ; analogs & derivatives ; chemistry ; isolation & purification ; Hydroxybenzoates ; chemistry ; isolation & purification ; Imines ; chemistry ; isolation & purification ; Lauric Acids ; chemistry ; isolation & purification ; Molecular Conformation ; Molecular Structure ; Parabens ; chemistry ; isolation & purification ; Plants, Medicinal ; chemistry ; Polypodiaceae ; chemistry ; Rhizome ; chemistry

We developed a new enzymatic-catalyzing producing process of glucose laurate monoester. In the process we used Candida antarctica lipase B-displaying Pichia pastoris whole-cells as biocatalyst, glucose as the acyl acceptor and lauric acid as the acyl donor. The product glucose laurate monoester was purified by silica gel column chromatography and preparative liquid chromatography, and identified by liquid chromatography-mass spectrometry. Then we optimized the process from various aspects, such as solvent composition, ratio of dmethyl sulfoxide to 2-Methyl-2-butanol (V/V), catalyst dosage, substrate concentration, water activity and temperature. The optimal reaction conditions were: glucose 0.5 mmol/L, lauric acid 1.0 mmol/L, ratio of 2-Methyl-2-butanol to Dmethyl sulfoxide is 7:3 in 5 mL volume, temperature 60 degrees C, the best initial water activity of whole-cells biocatalyst is 0.11. The maximum glucose conversion could be 48.7% after 72 h.
Biocatalysis ; Candida ; enzymology ; Esters ; chemistry ; metabolism ; Fungal Proteins ; Genetic Engineering ; Glucose ; chemistry ; metabolism ; Laurates ; chemistry ; metabolism ; Lipase ; biosynthesis ; genetics ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics

Glycerol monolaurate (GML) has been widely used as an effective antibacterial emulsifier in the food industry. A total of 360 44-week-old Hy-Line brown laying hens were randomly distributed into four groups each with six replicates of 15 birds, and fed with corn-soybean-meal-based diets supplemented with 0, 0.15, 0.30, and 0.45 g/kg GML, respectively. Our results showed that 0.15, 0.30, and 0.45 g/kg GML treatments significantly decreased feed conversion ratios (FCRs) by 2.65%, 7.08%, and 3.54%, respectively, and significantly increased the laying rates and average egg weights. For egg quality, GML drastically increased albumen height and Haugh units, and enhanced yolk color. Notably, GML increased the concentrations of polyunsaturated and monounsaturated fatty acids and reduced the concentration of total saturated fatty acids in the yolk. The albumen composition was also significantly modified, with an increase of 1.02% in total protein content, and increased contents of His (4.55%) and Glu (2.02%) under the 0.30 g/kg GML treatment. Additionally, GML treatments had positive effects on the lipid metabolism of laying hens, including lowering the serum triglyceride and total cholesterol levels and reducing fat deposition in abdominal adipose tissue. Intestinal morphology was also improved by GML treatment, with increased villus length and villus height to crypt depth ratio. Our data demonstrated that GML supplementation of laying hens could have beneficial effects on both their productivity and physiological properties, which indicates the potential application of GML as a functional feed additive and gives us a new insight into this traditional food additive.
Albumins/analysis* ; Animals ; Chickens ; Diet ; Dietary Supplements ; Egg Yolk/chemistry* ; Female ; Gonadal Steroid Hormones/blood* ; Intestines/cytology* ; Laurates/administration & dosage* ; Lipid Metabolism ; Monoglycerides/administration & dosage* ; Oviposition/drug effects* ; Ovum ; Oxidative Stress

The inherent evolvability of promiscuous enzymes endows them with great potential to be artificially evolved for novel functions. Previously, we succeeded in transforming a promiscuous acylaminoacyl peptidase (apAAP) from the hyperthermophilic archaeon Aeropyrum pernix K1 into a specific carboxylesterase by making a single mutation. In order to fulfill the urgent requirement of thermostable lipolytic enzymes, in this paper we describe how the substrate preference of apAAP can be further changed from p-nitrophenyl caprylate (pNP-C8) to p-nitrophenyl laurate (pNP-C12) by protein and solvent engineering. After one round of directed evolution and subsequent saturation mutagenesis at selected residues in the active site, three variants with enhanced activity towards pNP-C12 were identified. Additionally, a combined mutant W474V/F488G/R526V/T560W was generated, which had the highest catalytic efficiency (k (cat)/K (m)) for pNP-C12, about 71-fold higher than the wild type. Its activity was further increased by solvent engineering, resulting in an activity enhancement of 280-fold compared with the wild type in the presence of 30% DMSO. The structural basis for the improved activity was studied by substrate docking and molecular dynamics simulation. It was revealed that W474V and F488G mutations caused a significant change in the geometry of the active center, which may facilitate binding and subsequent hydrolysis of bulky substrates. In conclusion, the combination of protein and solvent engineering may be an effective approach to improve the activities of promiscuous enzymes and could be used to create naturally rare hyperthermophilic enzymes.
Aeropyrum ; chemistry ; enzymology ; Archaeal Proteins ; genetics ; metabolism ; Binding Sites ; Biocatalysis ; Caprylates ; metabolism ; Cloning, Molecular ; Dimethyl Sulfoxide ; chemistry ; Escherichia coli ; Hot Temperature ; Industrial Microbiology ; methods ; Kinetics ; Laurates ; metabolism ; Molecular Dynamics Simulation ; Mutagenesis, Site-Directed ; methods ; Peptide Hydrolases ; genetics ; metabolism ; Protein Binding ; Protein Conformation ; Recombinant Proteins ; genetics ; metabolism ; Solvents ; chemistry ; Substrate Specificity