Immobilization of flavin adenine dinucleotide (FAD) onto carbon cloth and its application as working electrode in an electroenzymatic bioreactor.

A high porosity carbon cloth with immobilized FAD was employed as working electrode in electrochemical NADH-regeneration procedure. Carbon cloth was oxidized with hot acids to create surface carboxyl group and then coupled by adenine amino group of FAD with carbodiimide in the presence of N-hydroxysulfosuccinimide. The bioelectrocatalytic NADH-regeneration was coupled to the conversion of achiral substrate pyruvate into chiral product l-lactate by l-lactate dehydrogenase (l-LDH) within the same reactor. The conversion was completed at 96h in bioreactor with FAD-modified carbon cloth, resulting in about 6mM of l-lactate from 10mM of pyruvate. While with bare carbon cloth, the yield at 120h was around 5mM. Immobilized FAD on the surface of carbon cloth electrode facilitated it to carry electrons from electrode to electron transfer enzymes; thereby NADH-regeneration was accelerated to drive the enzymatic reaction efficiently.

Effect of proanthocyanidin-rich extract from Pinus radiata bark on immune response of specific-pathogen-free White Leghorn chickens.

Proanthocyanidins are naturally occurring compounds that are widely found in fruits, vegetables, nuts, seeds, flowers, and bark. We evaluated the immunomodulatory effects of proanthocyanidin-rich extract (PAE) from Pinus radiata bark in specific-pathogen-free White Leghorn chickens. Proliferation of peripheral blood mononuclear cells was significantly enhanced in chickens treated for 2 wk with 20 mg/kg of PAE. Proliferation of splenocytes and bursal cells was significantly enhanced in chickens treated for 5 wk with 5, 10, and 20 mg/kg of PAE. Thymocyte proliferation was significantly enhanced in chickens treated for 5 wk with 5 and 10 mg/kg of PAE. These effects were markedly enhanced by the presence of lipopolysaccharide, which acted on B cells responsible for humoral immunity, and concanavalin A, which acted directly on T cells involved in cell-mediated immunity. The PAE significantly promoted the expression of T helper 1 cytokine (interferon-γ) and decreased the expression of T helper 2 cytokine (IL-6). Thus, P. radiata PAE has immunomodulatory effects in specific-pathogen-free White Leghorn chickens.

Role of bicontinuous microemulsion in the rapid enzymatic hydrolysis of (R,S)-ketoprofen ethyl ester in a micro-reactor.

Bicontinuous microemulsion was employed as the medium for enzymatic hydrolysis of (R,S)-ketoprofen ethyl ester in the presence of esterase for the first time. In addition, a methodology for the separation of optically pure ketoprofen from the microemulsion system for analysis by gas chromatography was developed. Various factors influencing the enzymatic hydrolysis of (R,S)-ketoprofen ethyl ester such as temperature, enzyme concentration and reaction time were optimized experimentally. The enzymatic hydrolysis in a bicontinuous microemulsion system showed a final conversion of 84.6% after 50 h of reaction, while hydrolysis in Tris-HCl buffer solution resulted in only 26.9% conversion after 150 h without completing the reaction. A comparison of the rate of the enzymatic hydrolysis reaction with rates of reaction in other biphasic media revealed that the bicontinuous microemulsion system was faster and more advantageous. The extremely large interfacial area of the latter fluid likely facilitated the contact between the catalyst and the substrate. Because the enzyme applied was not selective, formation of (R)-ketoprofen was also observed. Therefore, application of an enzyme with higher selectivity would provide better results.

Antibacterial activity of hydroxyalkenyl salicylic acids from sarcotesta of Ginkgo biloba against vancomycin-resistant Enterococcus.

A chloroform fraction prepared from the sarcotesta of Ginkgo biloba showed potent inhibitory activity against vancomycin-resistant Enterococcus (VRE). The active compounds were elucidated to be 2-hydroxy-6-(8-pentadecenyl) salicylic acid (1) and 2-hydroxy-6-(10-heptadecenyl) salicylic acid (2) based on their spectral analysis. Compounds 1 and 2 showed significant antibacterial activities against VRE.

Optimization of the extraction of anthocyanin from Bokbunja (Rubus coreanus Miq.) marc produced during traditional wine processing and characterization of the extracts.

The extraction of anthocyanin from Bokbunja (Rubus coreanus Miq.) marc generated during traditional wine processing was optimized using response surface methodology (RSM). A face-centered cube design (FCD) consisting of 17 experimental runs, including five replicates at the center point, was used to investigate the effects of the three variables (solid-liquid ratio, time, and temperature) on anthocyanin extraction, and the results showed that the relationship between the three variables and the total anthocyanin content followed a quadratic model (R2=0.8853). In addition, the RSM analysis predicted that the optimum conditions for extraction consisted of a solid-liquid ratio of 20, a time of 60min, and a temperature of 60 degrees C. Verification tests performed under these optimum conditions gave 34.7+/-1.4mg/100g of anthocyanin, which was close to predicted value of 37.2mg/100g. Additionally, analysis of water extracts prepared using the predicted optimum conditions revealed that the carbohydrates (sugar and pectin) in Bokbunja marc underwent significant variation toward the formation of by-products (glycerol and uronic acids) during yeast fermentation, and that the amount of anthocyanin produced was reduced 10-fold when compared to the original extraction. Further, the results of HPLC-PDA-MS/MS analysis of the anthocyanins extracted from Bokbunja marc revealed the presence of six anthocyanin components, which were tentatively identified as cyanidin 3-O-sambubioside, cyanidin 3-O-xylosylrutinoside, cyanidin 3-O-rutinoside, pelargonidin 3-O-rutinoside, delphinidin 3-O-rutinoside-?, and delphinidin 3-O-glucuronide.

Characterization of seed oils from fresh Bokbunja (Rubus coreanus Miq.) and wine processing waste.

The physicochemical characteristics, fatty acid (FA) profile, and triacylglyceride (TAG) composition of seed oils from fresh Bokbunja (Rubus coreanus Miq.) fruits and traditional Bokbunja wine processing waste were determined in this study. Oil contents of the fresh seeds and the seeds from wine processing waste were similar, accounting for about 18% of dry weight. The free fatty acid (FFA) content between the two seed oils was significantly different (0.50% for fresh seed oil and 73.14% for wine seed oil). Iodine, conjugated diene, saponification values, and unsaponifiable matter were very similar in the oil samples, but the specific extinction coefficients at 232 and 270 nm of wine seed oil were higher than those of fresh seed oil. Linoleic (C18:2, 50.45-53.18%, L) and linolenic (C18:3, 29.36-33.25%, Ln) acids were the dominant FAs in the two seed oils, whereas oleic (C18:1, 7.32-8.04%, O), palmitic (C16:0, 1.55-1.65%, P), and stearic (C18:0, 0.65-0.68%, S) acids were the minor FAs. LLL, OLL, LLLn, OOL, LLnLn, and OOO were the abundant TAGs, representing >90% of the oils.

Binding affinity of proanthocyanidin from waste Pinus radiata bark onto proline-rich bovine achilles tendon collagen type I.

Binding affinity of proanthocyanidin (PA) purified from Pinus radiata bark waste onto bovine Achilles tendon collagen (type I) was studied. Adsorption of PA onto the collagen was optimized by examining pH, contact time and temperature. The adsorption was pH-dependent. The maximum adsorption capacity (Q(0)) of PA on collagen was found to be 211 mg g(-1) using the Langmuir isotherm. Comparison between two adsorbents also showed that collagen had higher adsorptivity of approximately 20% more than PVPP (polyvinyl polypyrrolidone). The high affinity between PA and collagen was further confirmed in solvent solubility experiments. The observed solvent resistance was thought to be mainly due to a hydrophobic stacking mechanism reinforced by hydrogen bonding. FT-IR spectra clearly indicated the presence of PA adsorbed on collagen. The results have interesting implications that PA can be a good protective agent for collagen against collagenase and other enzymes.