ABSTRACT
In this paper we screened the dichloromethane extract from the aerial parts of Salvia officinalis L., Lamiaceae, against a representative panel of microorganisms that cause caries, conducted a bioassay-guided fractionation to establish themselves the most active metabolite (manool) and determined the Salvia officinalis fraction with the manool highest concentration to be used to activate an ingredient in oral care products such as toothpastes and mouthwashes. Both manool and S. officinalis extract showed very promising minimal inhibitory concentration values (between 6.24 and 31.36 µg.ml-1) and time kill curves against the primary causative agents of dental caries (Streptococcus mutans) revealed that, at twice its minimal bactericidal concentration (12.48 µg.ml-1), manool required 6 h to completely kill the bacteria. Salvia officinalis extract at twice its minimal bactericidal concentration (31.36 µg.ml-1 ) needed 12 h. The results achieved with Salvia officinalis extract motivated us to develop and validate an analytical RP-HPLC method to detect and determine manool in this extract. The validation parameters were satisfactorily met and evaluated allows us to consider the developed method suitable for use in different labs. In conclusion, our results evidenced that the manool-rich S. officinalis extract can be considered an analytically validated alternative to develop novel and effective antimicrobial agents against the main bacteria responsible for dental caries.
ABSTRACT
This work describes the phytochemical study of the extracts from aerial parts of Tibouchina candolleana as well as the evaluation of the antimicrobial activity of extracts, isolated compounds, and semi-synthetic derivatives of ursolic acid against endodontic bacteria. HRGC analysis of the n-hexane extract of T. candolleana allowed identification of b-amyrin, a-amyrin, and b-sitosterol as major constituents. The triterpenes ursolic acid and oleanolic acid were isolated from the methylene chloride extract and identified. In addition, the flavonoids luteolin and genistein were isolated from the ethanol extract and identified. The antimicrobial activity was investigated via determination of the minimum inhibitory concentration (MIC) using the broth microdilution method. Amongst the isolated compounds, ursolic acid was the most effective against the selected endodontic bacteria. As for the semi-synthetic ursolic acid derivatives, only the methyl ester derivative potentiated the activity against Bacteroides fragilis.
Subject(s)
Humans , Oleic Acids/isolation & purification , Methylene Chloride/isolation & purification , Plant Extracts/analysis , Plant Extracts/isolation & purification , Genistein/isolation & purification , Melastomataceae , Plant Structures , Triterpenes/isolation & purification , Methods , Microbial Sensitivity Tests , Plant PreparationsABSTRACT
The in vitro schistosomicidal effects of the essential oil obtained from Tagetes erecta L. Asteraceae, leaves (TE-EO) collected in Brazil against Schistosoma mansoni worms are reported in this paper. The oil caused a significant decrease in the motor activity at 50 µg/mL as minimal concentration after 24 h. This oil also caused death of all the parasites and the separation of coupled pairs into individual male and female at 100 µg/mL after 24 h. The viability of adult worm groups treated with the TE-EO at 100 µg/mL was similar to that of groups treated with praziquantel (positive control). In addition, the oil promoted the inhibition of eggs development at all the tested concentrations. These data indicate that the TE-EO could be considered as a promising source for the development of new schistosomicidal agents.
ABSTRACT
GC analysis of the dichloromethane extracts obtained from cultivated specimens of Mikania glomerata Sprengel possibilited to verify that cuttings technique led to production of kaurenoic acid and coumarin while the same results have not been observed by propagation process using in vitro techniques.
A análise realizada por CG dos extratos diclorometânicos das folhas de Mikania glomerata Sprengel mostrou que a planta propagada por estaca produziu cumarina e ácido caurenóico, enquanto que o material micropropagado acumulou apenas cumarina.
ABSTRACT
O objetivo deste trabalho foi avaliar a sazonalidade sobre o teor de saponinas e o isolamento e elucidação estrutural de constituinte químico (flavona) de Baccharis trimera (Less.) DC (Carqueja). O cultivo de indivíduos estaminados de B. trimera foi realizado no Campo Experimental da Universidade de Ribeirão Preto - Unaerp, em Ribeirão Preto, no período de janeiro a dezembro de 1998 e foi conduzido em três blocos, sendo que cada um deles era constituído de 48 mudas. As amostras foram colhidas após seis meses do plantio (durante o inverno), três meses após a primeira colheita (durante a primavera) e três meses após a segunda colheita (durante o verão). Após processo de secagem e moagem, as drogas foram submetidas ao ensaio para obtenção do índice de espuma. Os resultados mostraram que não há variabilidade neste índice em função da época de colheita. Parte da droga colhida no verão sofreu análise química para isolamento e elucidação estrutural de componente químico. O isolamento a partir do extrato metanólico de partes aéreas de B. trimera foi realizado através de métodos cromatográficos (CC e CLAE) e a identificação estrutural da substância isolada, através de métodos espectrométricos (UV, RMN ¹H e 13C). Foi identificada a flavona denominada 5,6-diidroxi-7,3,4-trimetoxiflavona.
The aim of this study was to evaluate the seasonal effect on the foam index and the isolation and structural identification of a chemical constituent (flavone) of Baccharis trimera. The culture staminate samples of B. trimera were realized in the experimental cultivation area of the Universidade de Ribeirão Preto - Unaerp, in Ribeirão Preto, state of São Paulo, Brazil from January to December/1998 and were conduced in three blocks, which received 48 seedlings. The samples were harvested six months after installation (during the winter), three months after the first harvest (during the spring) and three months after the second harvest (during the summer). After the drying process and comminution, an assay to obtain the foam index was performed with the plant material. The results didn't show any alteration, independently of harvest times. Part of the dried plant that had been harvested during the summer was extracted to isolate and identify structurally the chemical compound. The isolation from the methanol extracts of the aerial parts of B. trimera has been performed through chromatographic methods (CC and HPLC) and the identification through spectrometric methods (UV, ¹H and 13C NMR). A flavone was identified as 5,6-dihidroxy-7,3,4-trimetoxiflavone.