Immobilization of Amano lipase AK from Pseudomonas fluorescens on different types of chitosan-containing supports: use in the kinetic resolution of rac-indanol.

Amano lipase AK from P. fluorescens was immobilized on different types of chitosan-containing supports. Chitosan lower molecular weight (2.5%), chitosan lower molecular weight/sodium alginate (2.5%/2.5%) and chitosan lower molecular weight/carrageenan (2.5%/2.5%) allowed the highest values of immobilization yields (IY) of 81, 81 and 83%, respectively. Best activity results were achieved using chitosan average molecular weight (5%) and chitosan lower molecular weight/sodium alginate (2.5%/2.5%) as support, with values of 1.40 and 1.30 UpNPB/ggel and with recovery activities of 45.75 and 35.6%, respectively. These derivatives were evaluated in the kinetic resolution of rac-indanol to obtain a key intermediate in the synthesis of a drug used in the treatment of Parkinson's disease. The most efficient derivatives in the kinetic resolution were lipase immobilized on chitosan average molecular weight (5.0%) and chitosan low molecular weight/sodium alginate, the latter leading to obtaining both (S)-indanol and (R)-indanyl acetate with > 99% ee and 50% conversion.

Eugenol derivatives: synthesis, characterization, and evaluation of antibacterial and antioxidant activities.

Eugenol is the major component of clove essential oil and has demonstrated relevant biological potential with well-known antimicrobial and antioxidant action. Therefore, this work carried out the synthesis, purification, characterization, and evaluation of the antioxidant and antibacterial potential of 19 eugenol derivatives. The derivatives were produced by esterification reactions in the hydroxyl group (-OH) of eugenol with different carboxylic acids and also by addition reactions in the double bond of the allyl group. The derivatives had a promising antibacterial potential, including a lower minimum inhibitory concentration of 500 µg/mL than eugenol (1000 µg/mL). In addition, the derivatives were active against bacterial strains (Escherichia coli, Staphylococcus aureus) that eugenol itself showed no activity, thus increasing the spectrum of antibacterial action. As for the antioxidant activity, it was observed that the derivatives that involved esterification reactions in the hydroxyl group (-OH) of the eugenol molecule's phenol resulted in a significant reduction of the antioxidant action (IC50 > 100 µg/mL) when compared with the eugenol precursor molecule (IC50 = 4.38 µg/mL). On the other hand, the structural changes located in the double bond affected much more smoothly the capacity of capturing radicals than the starting molecule, also being obtained derivatives with proximal antioxidant capacity (IC50 = 19.30 µg/mL) to commercial standards such as Trolox (IC50 = 16.00 µg/mL).

Biflorin induces cytotoxicity by DNA interaction in genetically different human melanoma cell lines.

Cancer is a public health problem and the second leading cause of death worldwide. The incidence of cutaneous melanoma has been notably increasing, resulting in high aggressiveness and poor survival rates. Taking into account the antitumor activity of biflorin, a substance isolated from Capraria biflora L. roots that is cytotoxic in vitro and in vivo, this study aimed to demonstrate the action of biflorin against three established human melanoma cell lines that recapitulate the molecular landscape of the disease in terms of genetic alterations and mutations, such as the TP53, NRAS and BRAF genes. The results presented here indicate that biflorin reduces the viability of melanoma cell lines by DNA interactions. Biflorin causes single and double DNA strand breaks, consequently inhibiting cell cycle progression, replication and DNA repair and promoting apoptosis. Our data suggest that biflorin could be considered as a future therapeutic option for managing melanoma.

Recent Advances in Lipase-Mediated Preparation of Pharmaceuticals and Their Intermediates.

Biocatalysis offers an alternative approach to conventional chemical processes for the production of single-isomer chiral drugs. Lipases are one of the most used enzymes in the synthesis of enantiomerically pure intermediates. The use of this type of enzyme is mainly due to the characteristics of their regio-, chemo- and enantioselectivity in the resolution process of racemates, without the use of cofactors. Moreover, this class of enzymes has generally excellent stability in the presence of organic solvents, facilitating the solubility of the organic substrate to be modified. Further improvements and new applications have been achieved in the syntheses of biologically active compounds catalyzed by lipases. This review critically reports and discusses examples from recent literature (2007 to mid-2015), concerning the synthesis of enantiomerically pure active pharmaceutical ingredients (APIs) and their intermediates in which the key step involves the action of a lipase.

Alterations in brain amino acid metabolism and inhibitory effects on PKC are possibly correlated with anticonvulsant effects of the isomeric mixture of α- and ß-amyrin from Protium heptaphyllum.

CONTEXT: α- and ß-Amyrin (AMY) from Protium heptaphyllum (Aubl) March (Burseraceae) is found in Brazil and used in diverse inflammation-related diseases. This species presents a central action, as previously described. OBJECTIVE: The objectives were to evaluate the anticonvulsant effect of AMY in mice and to verify the mechanism of action. MATERIAL AND METHODS: Seizures were induced by pentylenetetrazole followed by acute or subchronic treatments (5-25 mg/kg, p.o. and i.p.) and determination of brain amino acids (10 and 25 mg/kg, i.p., 7 d). RESULTS: In the acute treatment, AMY (10, 25, and 50 mg/kg, p.o.) increased the latency to the first convulsion (FC) by 30, 44, and 40% and time to death (TD) by 36, 52, and 42%, respectively. When administered intraperitoneally, the same doses increased FC by 62, 75, and 73% and TD by 76, 82, and 119%, respectively. Combined with polymixin or staurosporine, AMY (25 mg/kg, i.p.) increased TD by 61 and 63%, respectively, as related to each drug alone. When subchronically administered (25 and 50 mg/kg, i.p.) increased FC by 75 and 101% and TD by 86 and 124%, respectively. AMY increased taurine (116 and 76%) and tyrosine concentrations (135 and 110%) in basal ganglia and hippocampus, respectively, and decreased by 68, 65, and 62% glutamate, aspartate, and GABA in basal ganglia. CONCLUSION: Thus, the AMY anticonvulsant activity is related to the GABAergic system and may be linked to the inhibition of the signaling cascade of PKC as well as to alterations in amino acids metabolism.

Triterpenes from Protium hebetatum resin.

Three olean (beta-amyrenone, beta-amyrin and maniladiol), three ursane (alpha-amyrinone, alpha-amyrin and breine) and four tirucallane (3-oxotirucalla-8,24-dien-21-6ic acid, 3alpha-hydroxytirucalla-8,24-dien-21-oic acid, 3alpha-acetoxytirucalla-8,24-dien-21-oic acid and 3alpha-hydroxytirucalla-7,24-dien-21-oic acid) triterpenes were isolated from the oleoresin of Protium hebetatum Daly. The structures were established mainly by 13C, 1D and 2D NMR spectroscopic analysis. The isolation of 3alpha-hydroxytirucalla-8,24-dien-21-oic acid permitted correction of the chemical shift assignments of some of its carbon atoms.

Antiplaque and antigingivitis effects of a gel containing Punica granatum Linn extract: a double-blind clinical study in humans.

OBJECTIVES: The antiplaque and antigingivitis effects of a gel containing 10% Punica granatum Linn extract were evaluated using a 21-day partial-mouth experimental model of gingivitis. METHODS: 23 volunteers participated in this cross-over, double-blind study, carried out in 2 phases of 21 days each. For each period of the experiment, an acrylic toothshield was made for each volunteer to carry the test or placebo gel as well as to avoid brushing of the 4 experimental teeth (posterior teeth in the lower left quadrant). The subjects were randomly assigned to use either the placebo gel (control group) or the test gel (experimental group) and were instructed to brush the remaining teeth normally 3 times a day. On days 0 and 21, the visible plaque index (VPI) and gingival bleeding index (GBI) were recorded. RESULTS: The results did not show statistically significant difference between control and experimental groups for either of the indices (VPI and GBI). CONCLUSION: The gel containing 10% Punica granatum Linn extract was not efficient in preventing supragingival dental plaque formation and gingivitis.