ABSTRACT
This work describes the preparation of a microhydrogel composite from cellulose nanowhiskers (CNW) and starch in an ultrasound assisted-emulsion. CNW, which showed rod-like morphology, was obtained by acid hydrolysis of cane-based cellulose. The introduction of vinyl bonds to both CNW and starch enabled us to create the microhydrogel composite in which CNW played a role as a covalent cross-linker. Furthermore, CNW may act as an emulsifying agent for emulsion, improving both sphericity and homogeneity of the microparticles. The drug release was regulated in response to changes in the CNW amounts. The modeling of the release kinetics indicated that the drug release is driven by an anomalous mechanism and that the addition of CNW to starch microparticles led to differences in that mechanism. The release rate became ca. 2.9 times slower when CNW is added. When combined with starch, CNW played a role as a retardant factor for drug release.
Subject(s)
Cellulose/chemistry , Drug Delivery Systems , Hydrogels/chemistry , Nanostructures/chemistry , Starch/chemistry , Drug Liberation , Hydrolysis , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Nanostructures/ultrastructure , Saccharum , Spectroscopy, Fourier Transform Infrared , Vitamin B 12/chemistry , X-Ray DiffractionABSTRACT
A series of new thiosemicarbazones derived from natural diterpene kaurenoic acid were synthesized and tested against the epimastigote forms of Trypanosoma cruzi to evaluate their antitrypanosomal potential. Seven of the synthesized thiosemicarbazones were more active than kaurenoic acid with IC50 values between 2-24.0 mM. The o-nitro-benzaldehyde-thiosemicarbazone derivative was the most active compound with IC50 of 2.0 mM. The results show that the structural modifications accomplished enhanced the antitrypanosomal activity of these compounds. Besides, the thiocyanate, thiosemicarbazide and the p- methyl, p-methoxy, p-dimethylamine, m-nitro and o-chlorobenzaldehyde-thiosemicarbazone derivatives displayed lower toxicity for LLMCK2 cells than kaurenoic acid, exhibing an IC50 of 59.5 mM.
Subject(s)
Benzaldehydes/chemistry , Diterpenes/chemistry , Thiosemicarbazones/chemistry , Trypanocidal Agents/chemistry , Animals , Benzaldehydes/pharmacology , Inhibitory Concentration 50 , Molecular Structure , Thiosemicarbazones/pharmacology , Trypanocidal Agents/pharmacology , Trypanosoma cruzi/drug effectsABSTRACT
Extratos de Croton fluribundus (Euphorbiaceae), ácido caurenóico e dois derivados do ácido caurenóico foram avaliados como moluscicida, cercaricida e também foi verificada a letalidade destas amostras frente a larvas de Artemia salina Leach. Nestes ensaios foram observadas significantes atividades moluscicida e cercaricida associadas a uma reduzida toxicidade frente ao camarão de água salgada.
Lethality of the extracts of Croton floribundus (Euphorbiaceae), a medicinal plant from south Brazil, and of the kaurenoic acid, an isolated compound, and two of its derivatives against adult Biomphalaria glabrata snails, Schistosoma mansoni cercariae and Artemia salina Leach. brine shrimp larvae are reported. Both extracts and the isolated compound showed significant molluscicidal and cercaricidal activities and reduced toxicity in brine shrimp assays.
