Polygonum cuspidatum extracts as bioactive antioxidaion, anti-tyrosinase, immune stimulation and anticancer agents.

In our study, it was applied for the technology of supercritical fluid carbon dioxide extraction to achieve biological constitutes from a Taiwan native plant, Polygonum cuspidatum. We developed bioactive effects of P. cuspidatum extracts via multiple examinations that established bio-purposes at a range of dosage ranges. The research of P. cuspidatum extracts indicated that they possessed anti-oxidative properties on radical-scavenging abilities, reducing activities and metal chelating powers in dose-dependant manners. The extracts also had minor in vitro mushroom tyrosinase suppression and decreased cellular tyrosinase activities and melanin production in B16-F10 cells. Immunologically, P. cuspidatum extracts enhanced the release of tumor necrosis factor α (TNF-α) induced by THP-1 macrophage cell line. In addition, the cell proliferation showed anti-proliferation in dose-dependent manner on human skin melanoma cells, A375 and A375.S2, of the extracts suggesting biological constitutes employed the anti-cancer possessions. This is the first statement presenting bioactivities on P. cuspidatum extracts including anti-oxidation, immune stimulation, anti-tyrosinase and anti-melanoma as far as we know.

Functional ginger extracts from supercritical fluid carbon dioxide extraction via in vitro and in vivo assays: antioxidation, antimicroorganism, and mice xenografts models.

Supercritical fluid carbon dioxide extraction technology was developed to gain the active components from a Taiwan native plant, Zingiber officinale (ginger). We studied the biological effects of ginger extracts via multiple assays and demonstrated the biofunctions in each platform. Investigations of ginger extracts indicated antioxidative properties in dose-dependant manners on radical scavenging activities, reducing powers and metal chelating powers. We found that ginger extracts processed moderate scavenging values, middle metal chelating levels, and slight ferric reducing powers. The antibacterial susceptibility of ginger extracts on Staphylococcus aureus, Streptococcus sobrinus, S. mutans, and Escherichia coli was determined with the broth microdilution method technique. The ginger extracts had operative antimicroorganism potentials against both Gram-positive and Gram-negative bacteria. We further discovered the strong inhibitions of ginger extracts on lethal carcinogenic melanoma through in vivo xenograft model. To sum up, the data confirmed the possible applications as medical cosmetology agents, pharmaceutical antibiotics, and food supplements.

Lipase catalyzed acetylation of 3,5,4'-trihydroxystilbene: optimization and kinetics study.

The use of immobilized lipase from Candida antarctica (Novozym(®) 435) to catalyze acetylation of trans-3,5,4'-trihydroxystilbene was investigated in this study. Response surface methodology and 5-level-4-factor central composite rotatable design were adopted to evaluate the effects of synthesis variables, including reaction time (24-72 h), temperature (25-65 °C), substrate molar ratio (1:15-1:75), and enzyme amount (600-3,000 PLU) on the percentage molar conversion of trans-4'-O-acetyl-3,5-dihydroxystilbene. The results showed that reaction temperature and enzyme amount were the most important parameters on percentage molar conversion. Based on ridge max analysis, the optimum conditions for synthesis were: reaction time 60 h, reaction temperature 64 °C, substrate molar ratio 1:56 and enzyme amount 2,293 PLU. The molar conversion of actual experimental values was 95% under optimal conditions. The synthesis product was analyzed using HPLC, mass and NMR. The results revealed that the major product was trans-4'-O-acetyl-3,5-dihydroxystilbene. The reaction kinetics was found to follow the Ping-Pong mechanism; substrate inhibition was not found at high vinyl acetate concentration.

Green and efficient production of octyl hydroxyphenylpropionate using an ultrasound-assisted packed-bed bioreactor.

A solvent-free system to produce octyl hydroxyphenylpropionate (OHPP) from p-hydroxyphenylpropionic acid (HPPA) and octanol using immobilized lipase (Novozym® 435) as a catalyst in an ultrasound-assisted packed-bed bioreactor was investigated. Response-surface methodology (RSM) and a three-level-three-factor Box-Behnken design were employed to evaluate the effects of reaction temperature (x1), flow rate (x2) and ultrasonic power (x3) on the percentage of molar production of OHPP. The results indicate that the reaction temperature and flow rate were the most important variables in optimizing the production of OHPP. Based on a ridge max analysis, the optimum conditions for OHPP synthesis were predicted to consist of a reaction temperature of 65°C, a flow rate of 0.05 ml/min and an ultrasonic power of 1.74 W/cm² with a yield of 99.25%. A reaction was performed under these optimal conditions, and a yield of 99.33 ± 0.1% was obtained.

Continuous production of lipase-catalyzed biodiesel in a packed-bed reactor: optimization and enzyme reuse study.

An optimal continuous production of biodiesel by methanolysis of soybean oil in a packed-bed reactor was developed using immobilized lipase (Novozym 435) as a catalyst in a tert-butanol solvent system. Response surface methodology (RSM) and Box-Behnken design were employed to evaluate the effects of reaction temperature, flow rate, and substrate molar ratio on the molar conversion of biodiesel. The results showed that flow rate and temperature have significant effects on the percentage of molar conversion. On the basis of ridge max analysis, the optimum conditions were as follows: flow rate 0.1 mL/min, temperature 52.1°C, and substrate molar ratio 1 : 4. The predicted and experimental values of molar conversion were 83.31 ± 2.07% and 82.81 ± .98%, respectively. Furthermore, the continuous process over 30 days showed no appreciable decrease in the molar conversion. The paper demonstrates the applicability of using immobilized lipase and a packed-bed reactor for continuous biodiesel synthesis.

Optimization of ultrasound-accelerated synthesis of enzymatic octyl hydroxyphenylpropionate by response surface methodology.

The ultrasound-accelerated enzymatic synthesis of octyl hydroxyphenylpropionate (OHPP) from p-hydroxyphenylpropionic acid (HPPA) and octanol was investigated in this study. A commercially available immobilized lipase from Candida antarctica, Novozym 435, was used as the biocatalyst. A three-level-three-factor Box-Behnken design experiment and response surface methodology were used to evaluate the effects of temperature, reaction time, and enzyme activity on percent yield of OHPP. The results indicated that temperature and enzyme activity significantly affected percent yield, whereas reaction time did not. A model for the synthesis of OHPP was established. Based on a ridge max analysis, the optimum conditions for OHPP synthesis were predicted to use a reaction temperature of 58.8°C, a reaction time of 14.6 h, and an enzyme activity of 410.5 PLU with a yield of 98.5%. A reaction was performed under these optimal conditions, and a yield of 97.5% ± 0.1% was obtained.

The effects of knowledge management on surgeon behavior.

Knowledge management is an important process for health care researchers and administrators. The way we manage and transfer knowledge in an organization can have a substantial impact on behavior and performance. In this article, we examine the behavioral effects of transferring performance-efficiency knowledge to a group of hospital-based surgeons. We observe the way the knowledge transfer impacts their sense of professional accountability and practice patterns for a limited set of diagnoses. We defined performance efficiency for a surgeon as the deviation from expected average length of inpatient hospital stay, and from expected average hospital charges (adjusted for risk and outcomes) for three of the most frequently performed and most costly surgical procedures in our subject hospital. We communicated knowledge of their performance efficiency to the group of hospital-based surgeons, along with benchmarked professional best practices, and included an identification of dimensions where performance could be improved. We then measured and compared their performance efficiency one year later. We did observe differences in performance efficiency, but not in consistent directions, and not in statistically significant magnitudes. Also, surgeons who initially had low levels of efficiency continued to have low levels of efficiency one year later. Within a professional accountability system, transfer of performance-efficiency knowledge alone did not provide sufficient motivation to induce consistent, significant change in practice behaviors among the group of surgeons. We conclude that medical opinion leaders and individualized strategies for surgeon motivation may have greater promise for improving performance efficiency if linked to the knowledge transfer system.