Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto

About: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto is a based out in . It is known for research contribution in the topics: Population & Genus. The organization has 2143 authors who have published 3674 publications receiving 71071 citations. The organization is also known as: FFCLRP & FFCLRP-USP.

Mutualistic Association between a Tiny Amazonian Stingless Bee and a Wax‐Producing Scale Insect1

Abstract: The Amazonian stingless bee Schwarzula sp. houses and attends, in its nest, soft scale insects, Cryptostigma sp. (Coccidae), from which obtains sweet secretions (honeydew) for their feeding and additional wax to build their nests. The bees nests in tunnels burrowed by moth larvae in branches of Campsiandra angustifolia, Caesalpiniaceae.

Characterization and properties of acid phosphatases with phytase activity produced by Aspergillus caespitosus

Abstract: High levels of thermostable acid phosphatases were produced by Aspergillus caespitosus in culture media supplemented with xylan birchwood or agricultural residues, as carbon sources. The optimal culture conditions for production of phosphatases were 40 degrees C and pH 6.0. Extra- and intra-cellular acid phosphatases were purified by chromatography on DEAE-cellulose, followed by concanavalin A-Sepharose affinity separation. Both extra- and intra-cellular enzymes were glycoproteins showing 63.0 and 58.3% of carbohydrate content respectively. Molecular masses estimated on Sepharose CL-6B column were 186 and 190+/-15 kDa, and 84 and 74+/-5 kDa according to SDS/PAGE, for extra- and intra-cellular acid phosphatases respectively. Taken together, these results suggest that both native enzymes were homodimers. Optimum temperature and pH for both phosphatase activities were 80 degrees C and 5.5 respectively. The extra- and intra-cellular acid phosphatases were stable for more than 60 min at 60 degrees C. The extracellular acid phosphatase was slightly inhibited by NaF, in contrast with the significant inhibition of the intracellular form. KH(2)PO(4) inhibited both activities equally. Both extra- and intracellular acid phosphatases were tartarate-resistant. Among several phosphorylated substrates used, the extracellular enzyme preferentially hydrolysed p-nitrophenyl phosphate. Kinetic parameters calculated for the hydrolysis of p-nitrophenyl phosphate by extracellular acid phosphatase were h (Hill coefficient)=1.2, K(0.5)=0.082 mM and V(max)=4.43 units/mg, whereas the intracellular enzyme exhibited Michaelian kinetics with K(m)=0.029 mM and V(max)=0.082 unit/mg. Phytase activity was also observed for both the enzymes, suggesting that they could be useful for biotechnological applications.

Chemical composition and evaluation of antileishmanial and cytotoxic activities of the essential oil from leaves of Cryptocarya aschersoniana Mez. (Lauraceae Juss.)

Abstract: Leishmaniasis is an endemic disease caused by protozoa of the genus Leishmania, which affects around two million people worldwide. One major drawback in the treatment of leishmaniasis is the emergence of resistance to current chemotherapeutics. Medicinal and aromatic plants constitute a major source of natural organic compounds. In this study, the leaf essential oil of Cryptocarya aschersoniana was obtained by hydrodistillation in a Clevenger-type apparatus, and the chemical composition was analyzed by GC-MS and GC-FID. The essential oil of these species was predominantly constituted by monoterpene hydrocarbons (48.8%). Limonene (42.3%), linalool (9.7%) and nerolidol (8.6%) were the main constituents in the oil of C. aschersoniana. The in vitro activity of the oil was evaluated against the promastigote forms of Leishmania amazonensis, the causative agent of cutaneous leishmaniasis in humans. The essential oil of C. aschersoniana showed high activity against L. amazonensis promastigote forms (IC50 = 4.46 µg/mL), however, it also demonstrated a relatively high cytotoxicity on mouse peritoneal macrophages (CC50 = 7.71 µg/mL). This is the first report of the chemical composition and the leishmanicidal and cytotoxic activities of the leaf essential oil of C. aschersoniana.