Ihosvany Camps

The addition of inulin and Lactobacillus casei 01 in sheep milk ice cream

The effect of the Lactobacillus casei 01 and inulin addition on sheep milk ice cream during storage (-18 °C, 150 days) was investigated. Control, probiotic and synbiotic ice cream (10% w/w sheep milk cream; 10% w/w sheep milk cream, L. casei 01, 6 log CFU/mL; 10% w/w inulin, L. casei 01, 6 log CFU/mL, respectively) were manufactured. Microbiological counts (probiotic count, survival after in vitro gastrointestinal resistance, Caco-2 cell adhesion), bioactivity and microstructure were analysed. Physical and textural characteristics, colour parameters, thermal analysis and organic acids/volatile compounds were also evaluated. All formulations supported L. casei 01 viability and maintained above the minimum therapeutic level (>6 log CFU/mL) during storage. Inulin did not affect L. casei 01 survival after the passage through simulated gastrointestinal tract and adhesion to Caco-2 cells while improved the ACE-inhibitory and antioxidant activity. L. casei 01 addition produced several volatile compounds, such as carboxylic acids, alcohols, aldehydes and ketones. Also, scanning electron microscopy showed an interaction between probiotic bacteria and inulin fibre on synbiotic ice cream and the adhesion of L. casei to Caco-2 cells was observed.

Semisynthesis and antimicrobial activity of novel guttiferone-A derivatives.

Six derivatives of guttiferone-A (LFQM-79, 80, 81, 82, 113 and 114) were synthesized and evaluated for their antimicrobial activity against the opportunistic or pathogenic fungi Candida albicans (ATCC 09548), Candida glabrata (ATCC 90030), Candida krusei (ATCC 6258), Candida parapsilosis (ATCC 69548), Candida tropicalis (ATCC 750), Cryptococcus neoformans (ATCC 90012), Trichophyton tonsurans, Microsporum gypseum and also against the opportunistic and pathogenic Gram-positive bacteria Staphylococcus aureus (ATCC 6538), Staphylococcus epidermidis (ATCC 12228), Bacillus cereus (ATCC 11778) and Gram-negative Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 9027), Salmonella typhimurium (ATCC 14028), Proteus mirabilis (ATCC 25933). The antimicrobial activities of derivatives were compared with guttiferone-A and they presented to be more potent than the original molecule and sometimes greater than standard drugs established in therapeutics. The current study showed that derivatives of guttiferone-A possess potent antimicrobial activity and are relatively non-cytotoxic, which reveal these new molecules as promising new drug prototype candidates, with innovative structural pattern.

Inhibition of cysteine proteases by a natural biflavone: behavioral evaluation of fukugetin as papain and cruzain inhibitor

Cruzain is the major cysteine protease of Trypanosoma cruzi, the infectious agent responsible for Chagas disease, and cruzain inhibitors display considerable antitrypanosomal activity. In the present work we elucidated crystallographic data of fukugetin, a biflavone isolated from Garcinia brasiliensis, and investigated the role of this molecule as cysteine protease inhibitor. The kinetic analyses demonstrated that fukugetin inhibited cruzain and papain by a slow reversible type inhibition with KI of 1.1 and 13.4 µM, respectively. However, cruzain inhibition was about 12 times faster than papain inhibition. Lineweaver–Burk plots demonstrated partial competitive inhibition for cruzain and hyperbolic mixed-type inhibition for papain. Furthermore, the docking results showed that the biflavone binds to ring C′ in the S2 pocket and to ring C in the S3 pocket through hydrophobic interactions and hydrogen bonds. Finally, fukugetin also presented inhibitory activity on proteases of the T. cruzi extract, with IC50 of 7 µM.

First-principles calculations of nickel, cadmium, and lead adsorption on a single-walled (10,0) carbon nanotube.

The adsorption of Ni, Cd, and Pb on a zigzag (10, 0) carbon nanotube (CNT) surface was investigated using density functional theory. Binding energy calculations were performed, and the results indicated that the three metals are stably adsorbed on the nanotube surface. Moreover, the results showed that Cd is physisorbed whereas Ni and Pb are chemisorbed. Our studies show that the electronic properties of the CNT are modified by the chemisorption mechanism (Ni and Pb). After Ni and Pb adsorption, the nanotube changes from being a semiconductor to a metallic conductor. The nanotube remains semiconductive upon Cd physisorption, although a decrease in the band gap is observed. Also, Ni or Pb adsorption triggers a change in the magnetism of the nanotube through the induction of spin polarization. Not only can these results of our calculations be used to explain the adsorption mechanisms of these heavy metals on the CNT, but they are also useful for evaluating the potential of carbon nanotubes (CNTs) to act as filters and sensors of such metals.

Computational Approach to the Discovery of Phytochemical Molecules with Therapeutic Potential Targets to the PKCZ protein

Background: Head and neck squamous cell carcinoma (HNSCC) is one of the most common malignancies in humans and the average 5-year survival rate is one of the lowest among aggressive cancers. Protein kinase C zeta (PKCZ) is highly expressed in head and neck tumors, and the inhibition of PKCZ reduces MAPK activation in five of seven head and neck tumors cell lines. Considering the world-wide HNSCC problems, there is an urgent need to develop new drugs to treat this disease, that present low toxicity, effective results and that are relatively inexpensive. Method: A unified approach involving homology modeling, docking and molecular dynamics simulations studies on PKCZ are presented. The in silico study on this enzyme was undertaken using 10 compounds from latex of Euphorbia tirucalli L. (aveloz). Results: The binding free energies highlight that the main contribution in energetic terms for the compounds-PKCZ interactions is based on van der Waals. The per-residue decomposition free energy from the PKCZ revealed that the compounds binding were favorably stabilized by residues Glu300, Ileu383 and Asp394. Based on the docking, Xscore and molecular dynamics results, euphol, ß-sitosterol and taraxasterol were confirmed as the promising lead compounds. Conclusion: The present study should therefore play a guiding role in the experimental design and development of euphol, ß-sitosterol and taraxasterol as anticancer agents in head and neck tumors. They are potential lead compounds, better than other ligands based on the best values of docking

Design, Synthesis, Biological Evaluation and Molecular Modeling Studies of Novel Eugenol Esters as Leishmanicidal Agents

The present study evaluated the inhibitory activity of new eugenol esters on Leishmania rCPB 2.8 enzyme aiming to discover new promising drug candidates. Activation and enhancement of the in vitro proteolytic activity of this enzyme were also produced by some compounds and may be related to their preference in binding to an allosteric site, possibly located in the region of the LYS159 residue, close to the active site. Details are presented in the Article Design, Synthesis, Biological Evaluation and Molecular Modeling Studies of Novel Eugenol Esters as Leishmanicidal Agents by Camila M. Coelho, Thiago dos Santos, Poliany G. Freitas, Juliana B. Nunes, Marcos J. Marques, Camila G. D. Padovani, Wagner A. S. Júdice, Ihosvany Camps, Nelson J. F. da Silveira, Diogo T. Carvalho and Marcia P. Veloso on page 715.

Order-disorder phase transition induced by proton transfer in a co-crystal of 2,4-dichlorobenzoic acid and trimethylamine N-oxide

A crystalline binary adduct between trimethylamine N-oxide (TMANO) and 2,4-dichlorobenzoic acid (2,4-DCBA) molecules was obtained by slow evaporation from acetonitrile. The obtained molecular complex is formed by a racemic mixture of molecular complexes crystallizing in the orthorhombic space group Pbca. An exhaustive analysis of the temperature dependence of the cell parameters and the behavior of the acidic hydrogen position and carboxylate group was performed by single crystal and powder X-ray diffraction, FT-IR spectroscopy and theoretical calculations. The molecular system was thermally characterized, subsequently demonstrating an order–disorder transition. Finally, the intermolecular interactions were analyzed via Hirshfeld surface analysis.

Structural Bioinformatics Approach of Cyclin-Dependent Kinases 1 and 3 Complexed with Inhibitors

The cyclin‐dependent kinases or CDKs participate in the regulation of both the cell progression cycle and the RNA polymerase‐II transcription cycle. In several human tumours deregulation of CDK‐related mechanisms have been detected, e.g., overexpression of cyclins or deletion of genes encoding for CKIs. Regarding these observations, CDKs came up to be interesting targets for elaboration of novel antitumour drugs. Based on the importance of the CDKs, this research aimed to describe, to characterize and to compare the molecular models of CDK1 and CDK3. Since the structures of human CDK1 and CDK3 are unavailable in the Protein Data Bank –PDB, homology models were created based on the CDK2 as the template, once they share a substantial identity. The structural studies of the CDK1 and CDK3 biding sites were conducted by molecular docking with 15 different CDK inhibitors previously identified to CDK2. This study allowed the understanding of the structure of the complexes between CDK1/ CDK3 with inhibitors. The knowledge of their structural features mainly the biding sites might be useful to discovery and rationalization of drug design process.