Sublethal effect of neem extract on mediterranean fruit fly adults

The sublethal effect of extracts of Azadirachta indica on Ceratitis capitata was evaluated. Two pairs of flies were treated in plastic tubes with cotton placed in plastic cages. An artificial diet (hydrolyzed protein + sugar) was provided ad libitum. The extracts affected significantly the longevity of C. capitata. The pre-oviposition period were not significantly affected by the extracts. The A. indica branches extracted with dichloromethane (888 ppm) affected significantly the fecundity and fertility, reducing the number of eggs laid to approximately 80 % and the egg hatching by 30 % at the 8th day. Therefore, the neem branches extracted with dichloromethane affected the reproduction of C. capitata.

Antifungal derivatives from Piper mollicomum and P. lhotzkyanum (Piperaceae)

Bioguided fractionation of the extracts from leaves of Piper mollicomum and Piper lhotzkyanum against the fungi Cladosporium cladosporioides and C. sphaerospermum afforded seven bioactive compounds, four being chromenes: methyl 2,2-dimethyl-2H-chromene-6-carboxylate, methyl 8-hydroxy-2,2-dimethyl-2H-chromene-6-carboxylate, 2-methyl-2-[4'-methyl-3'-pentenyl]-2H-1-benzopyran-6-carboxylic acid, 2,2-dimethyl-2H-chromene-6-carboxylic acid, one a dihydrochalcone: 2',6'-dihydroxy-4'-methoxydihydrochalcone, and two flavanones: 7-methoxy-5,4'-dihydroxy-flavanone and 7,4'-dimethoxy-5-hydroxy-flavanone. The structures of the bioactive isolated derivatives were elucidated by interpretation of their NMR data [¹H and 13C (BBD, DEPT 135º)], and mass spectral data as well as by comparison with data described in the literature.

Determinação de aflatoxina B1 em pimenta (Piper nigrum L.) e orégano (Origanum vulgare L.) por cromatografia em camada delgada e densitometria

An analytical study based on extraction with methanol-water, immunoaffinity cleanup and separation, identification and quantification of aflatoxin B1 by thin-layer chromatography,in ground black and white pepper and oregano was carried out. Validation of the applied methodology was done through accuracy and precision studies. Recoveries of aflatoxin B1 and relative standard deviations, from spice samples spiked at levels from 4.86 to 97.70 µg/kg, were, respectively, higher than 72% and lower than 20%. Application to spice samples available in Minas Gerais state, purchased at popular markets, showed no contamination with aflatoxin B1.

In vitro antimicrobial and antioxidant activities of a crude extract and fractions from Buddleja thyrsoides Lam. Leaves

Crude extract and fractions of Buddleja thyrsoides were investigated regarding antioxidant activities by DPPH, total phenolic contents by Folin-Ciocalteau and antimicrobial activity by the broth microdilution method. Total phenolics varied from 214.07 ± 3.6 to 438.4 ± 0.3 mg g-1. Crude extract, ethyl acetate, dichloromethane and butanolic fractions exhibited a weak scavenging activity (SC50=186.04 ± 10.8, 137.70 ± 8.5, 146.89 ± 9.0 and 165.71 ± 3.2 µg mL-1, respectively). A correlation between the antioxidant activities and total phenolic contents could be shown (r=0.857, p<0.01). The lowest value of MIC was observed with butanolic fraction against Saccharomyces cerevisiae (MIC and MFC at 62.5 µg mL-1). Dichloromethane and ethyl acetate fractions were effective against Staphylococcus aureus with MIC value at 250 and 500 µg mL-1 respectively.

Flavonas, lignanas e terpeno de Piper umbellata (Piperaceae)

The phytochemical investigation of Piper umbellata leaves yielded nine compounds including one terpenoid glucoside, five flavones (vitexin 2"-O-β-glucopyranoside, apigenin 8-C-β-D-glucopyranoside,orientin 8-C-β-D-glucopyranoside,5-hydroxy-7,3',4'-trimethoxy-flavone and velutin), two lignans (sesamin e dihydrocubebin) and 4-nerolidylcathecol. Excepting 4-nerolidylcathecol, all compounds have not been described from this species yet.

Caldensinic acid, a benzoic acid derivative and others compounds from Piper carniconnectivum

A benzoic acid derivative - caldensinic acid; E-phytyl hexadecanoate; β-sitosterol and stigmasterol mixture and phaeophytin a were isolated from the aerial parts of Piper carniconnectivum. The structures of these compounds were established unambiguously by IR, MS, 1D and 2D NMR analysis.

Determination of rutin and narcissin in marigold extract and topical formulations by liquid chromatography: applicability in skin penetration studies

A chromatographic technique for determination of rutin and narcissin in marigold extract and topical formulations was developed and validated. The method shows linearity over the concentration range of 0.2 - 6.0 μg/mL of rutin (r = 0.9986) and 0.8 - 12.0 μg/mL of narcissin (r = 0.9951). The values obtained for precision and accuracy are in agreement with ICH guidelines. Both the formulation excipients and the porcine ear skin samples did not interfere with the flavonoids determination. The recovery of rutin and narcissin in skin samples added with marigold extract was 81.41% and 83.35%, respectively, which demonstrate the applicability of this method to perform skin penetration studies.

Sensitive method for determination of piplartine, an alkaloid amide from Piper species, in rat plasma samples by liquid chromatography-tandem mass spectrometry

Piplartine (PPTN) is an alkaloid amide found in Piper species that presents different activities. PPTN determination in rat plasma is necessary to better understand its biological effects. The aim of this study was to develop a sensitive LC-MS/MS method for the determination of PPTN in rat plasma. The performance criteria for linearity, sensitivity, precision, accuracy, recovery, and stability have been assessed and were within the recommended guidelines. The validated method proved to be suitable in a pilot study of PPTN kinetic disposition in rat plasma after a single intraperitoneal dose, and represents an appropriate tool to further pharmacokinetic studies.

Composição química e avaliação da atividade antimicrobiana do óleo essencial das folhas de Piper malacophyllum (C. Presl.) C. DC.

This work reports the chemical composition as well as the antibacterial, antifungal and antiparasitic activities of the leaf essential oil from Piper malacophyllum. The oil was extracted by hydrodistillation and analyzed by GC-FID, GC-MS and polarimetry. Among the 28 compounds identified, (+)-camphor was the major constituent. The essential oil showed activity against most of the microorganisms tested, especially antifungal action, with a MIC of 500 µg mL-1 against Trichophyton mentagrophytes and Cryptococcus neoformans. This is the first study reporting the composition and biological properties of leaf essential oil from P. malacophyllum.

Influência da secagem sobre o rendimento e composição química dos compostos voláteis das raízes de Piper piscatorum Trel. & Yunck. (Piperaceae)

In this study, we evaluated the yield and chemical composition of volatile compounds obtained from fresh, dried at 30 and 40 ºC respectively of Piper piscatorum, employing the technique of hydrodistillation. The volatile were chemically characterized by GC-MS and GC-FID. The main volatile compounds were selin-11-en-4-a-ol (57,63 ± 3,07%; 53,95 ± 1,56% and 56,20 ± 0,43%) and benzyl benzoate (15,40 ± 0,36%; 16,32 ± 0,85% and 15,04 ± 0,24%).The drying of the raw material reduced yield of volatile compounds, changing their chemical compositions.

Chemical composition, circadian rhythm and antibacterial activity of essential oils of piper divaricatum: a new source of safrole

The essential oils from leaves, stems and fruits of Piper divaricatum were analyzed by GC-MS. The tissues showed high safrole content: leaves (98%), fruits (87%) and stems (83%), with yields of 2.0, 4.8 and 1.7%, respectively. This is a new alternative source of safrole, a compound widely used as a flavoring agent and insecticide. The leaf's oil showed antibacterial activity against gram-negative bacteria while safrole was active against Salmonella Typhimurium and Pseudomonas aeruginosa. In addition, the study of circadian rhythm of the safrole concentration in the essential oils of leaves showed a negligible variation of 92 to 98%.

Seasonal variation of the major secondary metabolites present in the extract of Eremanthus mattogrossensis Less (Asteraceae: Vernonieae) leaves

The species Eremanthus mattogrossensis, known as "veludo do cerrado" (cerrado velvet), is native to the Brazilian Cerrado. Because the amount of metabolites present in plants may be influenced by biological and environmental factors, here we conducted an HPLC-DAD-MS/MS investigation of the metabolite concentrations found in the MeOH/H2O extract of the leaves of this species. The main compounds were identified and quantified, and the metabolites were grouped by chemical class (caffeoylquinic acids, flavonoids, and sesquiterpene lactone). Statistical analysis indicated a straight correlation between the quantity of metabolites and seasonality, suggesting that environmental properties elicit important metabolic responses.

Occurrence, biological activities and 13C NMR data of amides from Piper (Piperaceae)

This manuscript describes an update review with up to 285 references concerning the occurrence of amides from a variety of species of the genus Piper (Piperaceae). Besides addressing occurrence, this review also describes the biological activities attributed to extracts and pure compounds, a compiled 13C NMR data set, the main correlations between structural and NMR spectroscopic data of these compounds, and employment of hyphened techniques such as LC-MS, GC-MS and NMR for analysis of amides from biological samples and crude Piper extracts.

Optimization of solvent mixtures for extraction from bark of Schinus terebinthifolius by a statistical mixture-design technique and development of a UV-Vis spectrophotometric method for analysis of total polyphenols in the extract

A statistical mixture-design technique was used to study the effects of different solvents and their mixtures on the yield, total polyphenol content, and antioxidant capacity of the crude extracts from the bark of Schinus terebinthifolius Raddi (Anacardiaceae). The experimental results and their response-surface models showed that ternary mixtures with equal portions of all the three solvents (water, ethanol and acetone) were better than the binary mixtures in generating crude extracts with the highest yield (22.04 ± 0.48%), total polyphenol content (29.39 ± 0.39%), and antioxidant capacity (6.38 ± 0.21). An analytical method was developed and validated for the determination of total polyphenols in the extracts. Optimal conditions for the various parameters in this analytical method, namely, the time for the chromophoric reaction to stabilize, wavelength of the absorption maxima to be monitored, the reference standard and the concentration of sodium carbonate were determined to be 5 min, 780 nm, pyrogallol, and 14.06% w v-1, respectively. UV-Vis spectrophotometric monitoring of the reaction under these conditions proved the method to be linear, specific, precise, accurate, reproducible, robust, and easy to perform.

Actividad insecticida sobre Spodoptera frugiperda (Lepidóptera: Noctuidae) de los compuestos aislados de la parte aérea de Piper septuplinervium (Miq.) c. dc. y las inflorescencias de Piper subtomentosum Trel. & Yunck. (Piperaceae)

The bioassay-guided purification of ethanolic extracts from inflorescences of Piper subtomentosum Trel. & Yunck and aerial part of Piper septuplinervium (Miq. ) C. DC. led to isolation of five flavonoids, uvangoletin (1), galangin (2), chrysin (5), 5-hydroxy-4',7-dimethoxy-flavone (6), pinostrobin (7); one amide, N-p-coumaroil-tyramine (4); one acylglycerol, monopalmitin (3); one derivative of acid, protocatechuic acid (8); and glycosydated sterol, daucosterol (9). Their structures were elucidated on the basis of spectroscopy and spectrometry data and by comparison with data reported in the literature. The isolated compounds were tested against Spodoptera frugiperda. The results showed galangin and protocatechuic acid to be the most active (LC 50 13.63 and 17.16 ppm, respectively).