Lipase-catalyzed ethanolysis of Jatropha curcas L. oil assisted by ultrasonication

ABSTRACT Transesterification of non-edible oils using immobilized lipase is a promising process for biodiesel production. Thus, this study aimed to evaluate the enzymatic transesterification of the non-edible Jatropha curcas oil for FAEE production under ultrasound irradiation in a solvent-free system. The effects of enzyme concentration, water concentration, molar ratio of ethanol to oil and ultrasound power on the FAEE conversion have been evaluated. The results show that enzyme concentration and irradiation power have a positive significant effect on FAEE conversion, where an increase in these variables leads to higher conversions. Conversion above 54% of FAEE was achieved with 1.5 hours of reaction time using ultrasound irradiation, reducing reaction time by at least 3 times, when compared with the same experimental conditions without ultrasound irradiation. Results showed that ultrasound can improve reaction conversion mainly by enhancing the mass transfer between the constituents of the reactions

Chemical Composition, Antioxidant, Antimicrobial and Antidiabetic Potential of Philodendron Bipinnatifidum Schott ex Endl

Many of the species used in popular medicine do not have their biological activities already proven by scientific studies. Among these species, the endemic South American Philodendron bipinnatifidum Schott ex Endl deserves special attention since it is already in use in popular medicine for inflammation cases, such as erysipelas, orchitis and ulcers. This study evaluated the antioxidant, antimicrobial and antidiabetic activities of extracts of the hastes de P. bipinnatifidum. The ethanolic extract showed a significant antioxidant potential. The ethyl acetate extract resulted in high antimicrobial activity against Streptococcus pyogenes. The most significant biological activity of ethyl acetate extract relates to its chemical composition when compared with ethanolic extract, which showed the highest concentration of bioactive compounds. In vitro antidiabetic activity was only evaluated for ethyl acetate extract, resulting in inhibition of intestinal disaccharidases (maltase and sucrase) at concentration of 500 μg/mL

Investigation on the Anticonvulsant Potential of Luteolin and Micronized Luteolin in Adult Zebrafish (Danio rerio)

Epilepsy affects around 50 million people worldwide, and an important number of patients (30%) fail to respond to any available antiepileptic drug. Previous studies have shown that luteolin presents a promising potential as an anticonvulsant. On the other hand, different studies showed that luteolin does not promote anticonvulsant effects. Therefore, there is a lack of consensus about the use of luteolin for seizure control. Luteolin low bioavailability could be a limiting factor to obtain better results. Attractively, micronization technology has been applied to improve flavonoids bioavailability. Thus, the present study aimed to investigate the effects of luteolin on its raw form and micronized luteolin in a PTZ-induced seizure model in adult zebrafish (Danio rerio). Our results demonstrate that luteolin and micronized luteolin did not block PTZ-induced seizures in adult zebrafish. Also, luteolin and micronized luteolin did not provoke behavioral changes. Finally, our results show that 24 h after seizure occurrence, no changes were detected for p70S6Kb, interleukin 1β, and caspase-3 transcript levels. Altogether, we failed to observe an anticonvulsant potential of luteolin in adult zebrafish, even in its micronized form. However, we recommend new studies to investigate luteolin benefits in epilepsy.Fil: Garbinato, Cristiane. No especifíca;Fil: Alves Lima Rezende, Cássia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Schneider, Sabrina Ester. No especifíca;Fil: Pedroso, Jefferson. No especifíca;Fil: dos Santos, Aline E.. Universidade Federal de Santa Catarina; BrasilFil: Petry, Fernanda. No especifíca;Fil: Aguiar, Gean Pablo S.. No especifíca;Fil: Girardi Müller, Liz. No especifíca;Fil: Lanza, Marcelo. Universidade Federal de Santa Catarina; BrasilFil: Piato, Angelo. Universidade Federal do Rio Grande do Sul; BrasilFil: Vladimir Oliveira, J.. Universidade Federal de Santa Catarina; BrasilFil: Siebel, Anna Maria. No especifíca

'Synthetic lipase' production from a newly isolated Sporidiobolus pararoseus strain by submerged fermentation

The lipase produced by a newly isolate Sporidiobolus pararoseus strain has potential catalysis ability for esterification reactions. In order to improve its synthetic activity, this work aimed at optimizing 'synthetic lipase' production by submerged fermentation of a conventional media based on peptone, yeast extract, NaCl and olive oil using experimental design technique. According to the results obtained in the first experimental design (2(4-1)), yeast extract and NaCl concentrations were tested to further optimization by response surface methodology. The maximum 'synthetic lipase' activity obtained was 26.9 U/mL in the optimized media (5.0, 6.8, 7.0 and 1.0% (wt/v) of peptone, yeast extract, NaCl and olive oil, respectively), representing a 6.36-fold increase compared to the initial medium. The time course of 'synthetic lipase' production in the optimized condition was evaluated in terms of synthetic activity, protease activity, biomass and total carbon and the maximum synthetic activity was observed during the stationary phase of growth

Concentration, characterization and application of lipases from Sporidiobolus pararoseus strain

Lipases produced by a newly isolated Sporidiobolus pararoseus strain have potential catalytic ability for esterification reactions. After production, the enzymatic extracts (conventional crude and precipitated, 'CC' and 'CP', and industrial crude and precipitated, 'IC' e 'IP') were partially characterized. The enzymes presented, in general, higher specificity for short chain alcohols and fatty acids. The precipitated extract showed a good thermal stability, higher than that for crude enzymatic extracts. The 'CC' and 'CP' enzymes presented high activities after exposure to pH 6.5 and 40 ºC. On the other hand, the 'IC' and 'IP' extracts kept their activities in a wide range of pH memory but presented preference for higher reaction temperatures. Preliminary studies of application of the crude lipase extract in the enzymatic production of geranyl propionate using geraniol and propionic acid as substrates in solvent-free system led to a reaction conversion of 42 ± 1.5%