Vicente Carlos de Oliveira Costa

In vitro antimicrobial activity of Caesalpinia ferrea Martius fruits against oral pathogens

AIM In the Amazon region of Brazil, the fruits of Caesalpinia ferrea Martius (Brazilian ironwood) are widely used as an antimicrobial and healing medicine in many situations including oral infections. This study aimed to evaluate the antimicrobial activity of Caesalpinia ferrea Martius fruit extract against oral pathogens. MATERIALS AND METHODS Polyphenols estimation and spectral analysis ((1)H NMR) of the methanol extract were carried out. The microorganisms Candida albicans, Streptococcus mutans, Streptococcus salivarius, Streptococcus oralis and Lactobacillus casei were tested using the microdilution method for planktonic cells (MIC) and a multispecies biofilm model. Chlorhexidine was used as positive control. RESULTS Polyphenols in the extract were estimated at 7.3% and (1)H NMR analysis revealed hydroxy phenols and methoxilated compounds. MIC values for Candida albicans, Streptococcus mutans, Streptococcus salivarius, Streptococcus oralis and Lactobacillus casei were 25.0, 40.0, 66.0, 100.0, 66.0 microg/mL, respectively. For the biofilm assay, chlorhexidine and plant extract showed no growth at 10(-4) and 10(-5) microbial dilution, respectively. At 10(-4) and 10(-5) the growth values (mean+/-SD) of the negative controls (DMSO and saline solution) for Streptococcus mutans, Streptococcus sp. and Candida albicans were 8.1+/-0.7, 7.0+/-0.6 and 5.9+/-0.9 x 10(6)CFU, respectively. CONCLUSION Caesalpinia ferrea fruit extract can inhibit in vitro growth of oral pathogens in planktonic and biofilm models supporting its use for oral infections.

Composição química e modulação da resistência bacteriana a drogas do óleo essencial das folhas de Rollinia leptopetala R. E. Fries

The essential oil from the leaves of Rollinia leptopetala was obtained by hydrodistillation in Clevengers apparatus and its chemical composition was analyzed by GC-MS. With this technique could be identified 22 constituents in a complex mixture of monoterpenes (54.5%) and sesquiterpenes (45.5%). The main component found in the leaves was the bicyclogermacrene (22.47%). The essential oil was assayed against a strain of Staphylococcus aureus possessing efflux mechanism of resistance to norfloxacin. Although the essential oil did not display relevant antibacterial activity in vitro, it modulated the activity of the norfloxacin, i.e. in combination with the antibiotic it was observed a fourfold reduction in the minimum inhibitory concentration for norfloxacin, indicating inhibition of efflux pump.

Constituintes químicos, avaliação das atividades citotóxica e antioxidante de Mimosa paraibana Barneby (Mimosaceae)

The phytochemical study of Mimosa paraibana Barneby led to the isolation of its chemical constituents, through the usual chromatographic methods, and further structural identification, using 1H and 13C NMR spectroscopic methods based on one and two-dimensional techniques, in addition to comparison with literature data. From this pioneering investigation with M. paraibana, five constituents were isolated and identified from the chloroform extract: a mixture of β-sitosterol and stigmasterol, 151-hydroxy-phaeophytin A, 5,7-dihydroxyflavanone, ethyl 3,4,5-trihydroxybenzoate and p-coumaric acid. The antioxidant activity of the hexane, chloroform and ethyl acetate extracts of M. paraibana were measured using the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay and the results compared with standard ascorbic acid. The toxicity activity of the extracts were performed using the bioassay of Artemia salina.

Bowdichine, a new diaza-adamantane alkaloid from Bowdichia virgilioides.

A novel alkaloid named bowdichine (1), only the third with a diaza-adamantane skeleton containing an unusual N-acetyl enamine moiety, and the known alkaloids acosmine (2), ormosanine (3) and podopetaline (4) have been isolated from the stem bark of Bowdichia virgilioides. The structures were elucidated on the basis of spectral data, mainly 1D and 2D NMR of the diaza-adamantane alkaloids 1 and 2.

Essential oil from the leaves of Xylopia langsdorfiana (Annonaceae) as a possible spasmolytic agent

Xylopia langsdorfiana A. St.-Hil. &Tul. (Annonaceae) is popularly known in the northeast of Brazil as ‘pimenteira da terra’, and an essential oil (XL-OE) was extracted from its leaves. Since Xylopia species are cited in folk medicine and diterpenes from X. langsdorfiana have spasmolytic activity, this study aimed to investigate a possible spasmolytic action of XL-OE on smooth muscle models. XL-OE (243 and 729 μg/mL) showed low pharmacologic efficacy on guinea pig trachea and rat aorta and uterus. However, in guinea pig ileum, XL-OE (27–729 μg/mL) inhibited carbachol or histamine-induced phasic contractions (1 μM) in a significant and concentration-dependent manner. In addition, XL-OE (81 μg/mL) reduced fluorescence intensity in ileal myocytes stimulated by histamine, indicating a decrease in cytosolic calcium concentration, which could explain the spasmolytic activity. Thus, XL-OE proved to be a promising natural product to be used in gastrointestinal diseases acting by modulating the cytosolic calcium concentration.

Flavonoides glicosilados de Erythroxylum pulchrum a. st.-hil. (Erythroxylaceae)

The phytochemical investigation of Erythroxylum pulchrum St. Hil. (Erythroxylaceae) led to the isolation of three known flavonoid glycosides quercetin-3-O-α-L-rhaminoside, ombuin-3-ruthinoside and ombuin-3-ruthinoside-5-glucoside. These flavonoids are being described for the first time in this E. pulchrum. The structures of the compounds were determined by analysis of IR, MS and NMR data, as well as by comparison with literature data. The methanolic extract of leaves from E. pulchrum inhibited the growth of the Bacillus subtilis CCT 0516, Escherichia coli ATCC 2536, Pseudomonas aeruginosa ATCC 8027, P. aeruginosa ATCC 25619, Staphylococcus aureus ATCC 6538, S. aureus ATCC 25925, Streptococcus sanguinis ATCC 15300, S. salivarius ATCC 7073, S. mutans ATCC 25175 and Streptococcus ATCC. S. aureus ATCC 25925 was the most sensitive among the other S. sanguinis while S. salivarius proved the most resistant.

Constituintes químicos das folhas de Rollinia leptopetala R. E. Fries

The phytochemical investigation of Rollinia leptopetala led to the isolation of a new compound named α-terpinyl caffeate, and five known compounds, being three sesquiterpenes, spathulenol, β-caryophyllene and 4β,10α-aromadendrane-diol, and two alkaloids, (-)-3-hydroxynornuciferine and (+)-norisocorydine. These alkaloids are being described for the first time in this genus. The structures of the compounds were determined by analysis of IR, MS and NMR data, as well as by comparison with literature data. The crude extract of R. leptopetala leaves demonstrated a weak cytotoxicity on sarcoma 180 cells with an IC50 of 512.3 µg/mL. However, the in vivo results showed that the extract exhibited a significant dose-dependent tumor growth reduction.

FLAVONOID GLYCOSIDES FROMErythroxylum pulchrumA. St.-Hil. (Erythroxylaceae)

The phytochemical investigation of Erythroxylum pulchrum St. Hil. (Erythroxylaceae) led to the isolation of three known flavonoid glycosides quercetin-3-O-α-L-rhaminoside, ombuin-3-ruthinoside and ombuin-3-ruthinoside-5-glucoside. These flavonoids are being described for the first time in this E. pulchrum. The structures of the compounds were determined by analysis of IR, MS and NMR data, as well as by comparison with literature data. The methanolic extract of leaves from E. pulchrum inhibited the growth of the Bacillus subtilis CCT 0516, Escherichia coli ATCC 2536, Pseudomonas aeruginosa ATCC 8027, P. aeruginosa ATCC 25619, Staphylococcus aureus ATCC 6538, S. aureus ATCC 25925, Streptococcus sanguinis ATCC 15300, S. salivarius ATCC 7073, S. mutans ATCC 25175 and Streptococcus ATCC. S. aureus ATCC 25925 was the most sensitive among the other S. sanguinis while S. salivarius proved the most resistant.

Croton grewioides Baill. (Euphorbiaceae) shows antidiarrheal activity in mice

Based on chemotaxonomy, we decided to investigate the possible antidiarrheal activity in mice of a crude ethanolic extract obtained from aerial parts of Croton grewioides (CG-EtOH). We tested for any possible toxicity in rat erythrocytes and acute toxicity in mice. Antidiarrheal activity was assessed by determining the effect of CG-EtOH on defecation frequency, liquid stool, intestinal motility and intestinal fluid accumulation. CG-EtOH showed no in vitro cytotoxicity and was not orally lethal. In contrast, the extract given intraperitoneally (at 2000 mg/kg) was lethal, but only in females. CG-EtOH produced a significant and equipotent antidiarrheal activity, both in defecation frequency (ED50 = 106.0 ± 8.1 mg/kg) and liquid stools (ED50 = 105.0 ± 9.2 mg/kg). However, CG-EtOH (125 mg/kg) decreased intestinal motility by only 22.7% ±4.4%. Moreover, extract markedly inhibited the castor oil-induced intestinal contents (ED50 = 34.6 ± 5.4 mg/kg). We thus conclude that CG-EtOH is not orally lethal and contains active principles with antidiarrheal activity, and this effect seems to involve mostly changes in intestinal secretion. SUMMARY CG-EtOH showed no in vitro cytotoxicity and was not orally lethal. In contrast the extract given intraperitoneally (at 2000 mg/kg) was lethal, but only in females. CG-EtOH probably contains active metabolites with antidiarrheal activity. CG-EtOH reduced the frequency and number of liquid stools. Metabolites presents in the CG-EtOH act mainly by reducing intestinal fluid and, to a lesser extent, reducing intestinal motility. Abbreviations Used: CG-EtOH: crude ethanolic extract obtained from the aerial parts of C. grewioides; WHO: World Health Organization; ED50: dose of a drug that produces 50% of its maximum effect; Emax: maximum effect

Maytensifolone, a new triterpene from Maytenus distichophylla Mart. ex Reissek

O estudo fitoquimico das folhas de Maytenus distichophylla Mart. ex Reissek levou ao isolamento de um novo triterpeno 3,16,21-trioxo-6β,12α-dihidroxi-1-en-friedelano, nomeado maytensifolona, juntamente com os triterpenos conhecidos, 3-oxofriedelano, 3,12-dioxofriedelano, 3β-hidroxifriedelano, 3-oxo-29-hidroxifriedelano, 3-oxo-12α-hidroxifriedelano e 3-oxo30-hidroxifriedelano. A identificacao estrutural foi baseada em metodos espectroscopicos e comparacao com dados da literatura Phytochemical study of the leaves of Maytenus distichophylla Mart. ex Reissek led to the isolation of the new triterpene 3,16,21-trioxo-6β,12α-dihydroxy-1-en-friedelane, named maytensifolone, along with the known triterpenes 3-oxofriedelane, 3,12-dioxofriedelane, 3β-hydroxyfriedelane, 3-oxo-29-hydroxyfriedelane, 3-oxo-12α-hydroxyfriedelane and 3-oxo30-hydroxyfriedelane. Their structural identification was based on spectroscopic methods and comparison with literature data.