Effect of γ-lactones and γ-lactams compounds on Streptococcus mutans biofilms

Abstract Considering oral diseases, antibiofilm compounds can decrease the accumulation of pathogenic species such as Streptococcus mutans at micro-areas of teeth, dental restorations or implant-supported prostheses. Objective To assess the effect of thirteen different novel lactam-based compounds on the inhibition of S. mutans biofilm formation. Material and methods We synthesized compounds based on γ-lactones analogues from rubrolides by a mucochloric acid process and converted them into their corresponding γ-hydroxy-γ-lactams by a reaction with isobutylamine and propylamine. Compounds concentrations ranging from 0.17 up to 87.5 μg mL-1 were tested against S. mutans. We diluted the exponential cultures in TSB and incubated them (37°C) in the presence of different γ-lactones or γ-lactams dilutions. Afterwards, we measured the planktonic growth by optical density at 630 nm and therefore assessed the biofilm density by the crystal violet staining method. Results Twelve compounds were active against biofilm formation, showing no effect on bacterial viability. Only one compound was inactive against both planktonic and biofilm growth. The highest biofilm inhibition (inhibition rate above 60%) was obtained for two compounds while three other compounds revealed an inhibition rate above 40%. Conclusions Twelve of the thirteen compounds revealed effective inhibition of S. mutans biofilm formation, with eight of them showing a specific antibiofilm effect.

Formulation and evaluation of rofecoxib capsules

Rofecoxib [ROF] is an analgesic, antipyretic and anti-inflammatory drug. It is a selective inhibitor of cyclooxygenase enzyme [Cox-2 inhibitor]. The aim of this work was to formulate and evaluate ROF capsules and compare them with a commercial ROF product. The ROF capsules were prepared using different excipients namely: Sta-Rx starch 1500, cellactose, anhydrous lactose and tablettose. Compatibility of the drug with the used excipients was studied by differential scanning calorimetry. The effect of cogrinding of ROF with either PVP 40000 or Avicel PH 101 in the ratio of 1:5 w/w on the drug release from the prepared capsules was also studied. Differential scanning calorimetry and x-ray diffraction studies showed reduction in crystallinity or conversion of the drug to an amorphous form upon grinding with either PVP 40000 or Avicel PH 101 respectively. All formulae of ROF capsules complied with the USP XXV requirements for uniformity of dosage units. Formulae No. 6 and 7 containing ground mixture of the drug with either PVP 4000 or Avicel PH 101 in a ratio of 1:5 drug to carrier and Sta-Rx starch 1500 as diluent gave a higher dissolution rate of ROF [t[50%] = 5 and 9 min., respectively] in comparison with the commercial ROF product Rhumacure [t[50%] = 25 min.] Moreover; the anti-inflammatory activity was studied in rats using paw-edema method and the results obtained were analyzed using ANOVA test at the level of significance [P

Sesquiterpene Lactones From Onopordum Ambiguum

The aerial parts of Onopordum ambiguum afforded a new dihydroxylated sesquiterpene lactone, namely, 8 alpha-[4-hydroxymethacryloyloxy]-1-epi-sonchucarpolide [1], a C-1 epimer of a perviously isolated eudesmanolide, in addition to the known germacranolide, onopordopicrin [2]. The known flavonoid 5,7,3',4'-tetrahydroxy-3-methoxyflavone was also isolated and characterized. The structure elucidation of the new compound was based primarily on 1D and 2D-NMR analyses

Efecto reductor de la lactona sesquiterpénica "Helenalina" y sus derivados metálicos en la formación del complejo estradiol receptor en tejido tumoral mamario / Reductive effect of sesquiterpenic lactone \"Helenaline\" and its metalic derivates in complex estradiol-receptor formation in breast tumoral tissue

Dentro de la terapia sistémica empleada para el tratamiento de cáncer mamario, ha sido extensamente utilizada la quimioterapia, la cual ha sido apoyada por muy diversos compuestos en cuanto a origen y composición química. Sin embargo, todos ellos, producen diversos efectos colaterales adeversos, dignos de tomarse en cuenta. Por este hecho, precisa estudiar nuevas posibilidades en donde el fármaco aplicado, actúa selectivamente sobre célula tumoral, sin lesionar tejido sano. Para su efecto, se estudió una gamma lactona llamada "Helenalina" y sus derivados metálicos He-Co, He-Hg y He-Cu, cuya composición química les permite reaccionar con residuos -SH presentes en el receptor de la célula tumoral, los cuales al intercalarse por una reacción previa, podría modificar su composición estructural y finalemente su afinidad por la hormona. Se investigó el efecto de inhibición para la formación del complejo estradiol-receptor en el citosol de tejido tumoral mamario empleando Helenalina a 12 n M y 126 n M, obteniéndose un efecto de inhibición de 14 por ciento y 56 por ciento respectivamente. Cuando se estudió He-Co, He-Hg y He-Cu este efecto se vió aumentado, obteniéndose 11 por ciento, 10.5 por ciento y 60 por ciento con 12 n m y 44.5 por ciento, 74.5 por ciento y 86 por ciento con 126 n M respectivamente