RESUMO
One new sesquiterpene dilactone, coccinine (1) and one new ß-carboline alkaloid, daibucarboline F (2) together with 10 known compounds; linderane (3), linderalactone (4), pseudoneolinderane (5), linderanlide C (6), linderanine A (7), epicatechin (8), (-)-taxifolin (9), astilbin (10), L-quercitrin (11) and afzelin (12) were isolated from the stems and leaves of Neolitsea cassia (L.) Kosterm (Lauraceae). The structures of (1 and 2) were established by extensive spectroscopic methods and the known compounds were identified by comparisons with data reported in literature. The relative stereochemistry of compound (1) was assigned by X-ray diffraction analysis with Cu-Kα irradiation. Compounds (3-8) and (10) were evaluated for their α-glucosidase enzymatic inhibitory activity. Compounds (4-6), (8) and (10) exhibited inhibition towards α-glucosidase enzymatic activity with IC50 values ranging from 12.10 to 96.77 µM. This is the first report on the isolation of phytochemicals from N. cassia and their bioactivities.
Assuntos
Alcaloides , Cassia , Lauraceae , Sesquiterpenos , Alcaloides/farmacologia , Carbolinas/farmacologia , Cassia/química , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Lauraceae/química , Estrutura Molecular , Compostos Fitoquímicos/farmacologia , Sesquiterpenos/química , Sesquiterpenos/farmacologia , alfa-Glucosidases/metabolismoRESUMO
[This corrects the article DOI: 10.1107/S2414314617002346.].
RESUMO
INTRODUCTION: Cassia singueana Del. (Fabaceae) is a rare medicinal plant used in the traditional medicine preparations to treat various ailments. The root of C. singueana is a rich source of anthraquinones that possess anticancer, antibacterial and antifungal properties. OBJECTIVE: The objective of this study was to develop an ultrasound-assisted extraction (UAE) method for achieving a high extraction yield of anthraquinones using the response surface methodology (RSM), Box-Behnken design (BBD), and a recycling preparative high-performance liquid chromatography (HPLC) protocol for isolation of anthraquinones from C. singueana. METHODOLOGY: Optimisation of UAE was performed using the Box-Behnken experimental design. Recycling preparative HPLC was employed to isolate anthraquinones from the root extract of C. singueana. RESULTS: The BBD was well-described by a quadratic polynomial model (R2 = 0.9751). The predicted optimal UAE conditions for a high extraction yield were obtained at: extraction time 25.00 min, temperature 50°C and solvent-sample ratio of 10 mL/g. Under the predicted conditions, the experimental value (1.65 ± 0.07%) closely agreed to the predicted yield (1.64%). The obtained crude extract of C. singueana root was subsequently purified to afford eight anthraquinones. CONCLUSION: The extraction protocol described here is suitable for large-scale extraction of anthraquinones from plant extracts.
Assuntos
Antraquinonas/isolamento & purificação , Cassia/química , Cromatografia Líquida de Alta Pressão/métodos , Raízes de Plantas/química , Projetos de Pesquisa , Ultrassom/métodos , Fracionamento Químico/métodos , Modelos Estatísticos , Extratos Vegetais/química , Espectroscopia de Prótons por Ressonância Magnética , Reprodutibilidade dos TestesRESUMO
In the present study, a series of fourteen 5-benzoyl-4-methyl-1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-2-one derivatives were designed, synthesized and characterized by appropriate spectral analysis. Further, titled compounds were in-vitro screened against wild HIV-1 RT enzyme using ELISA based colorimetric assay, in which four compounds significantly inhibited the RT activity with IC50≤25µM. Moreover, two significantly active compounds of the series, A10 and A11 exhibited IC50 values 8.62 and 6.87µM respectively, during the in-vitro assay. Structure Activity Relationship (SAR) studies were performed for the synthesized compounds in order to estimate the effect of substitution pattern on the RT inhibitory potency. The cytotoxicity of the synthesized compounds was evaluated against T lymphocytes. Further, putative binding modes of the significantly active (A11) and the least active (A4) compounds with wild HIV-1 RT were also investigated using docking studies.
Assuntos
Benzodiazepinas/farmacologia , Transcriptase Reversa do HIV/antagonistas & inibidores , Inibidores da Transcriptase Reversa/farmacologia , Benzodiazepinas/síntese química , Benzodiazepinas/química , Linfócitos T CD4-Positivos , Relação Dose-Resposta a Droga , Transcriptase Reversa do HIV/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Inibidores da Transcriptase Reversa/síntese química , Inibidores da Transcriptase Reversa/química , Relação Estrutura-AtividadeRESUMO
Hydrodistillation of the fresh stem and leaf of Neolitsea kedahense Gamble, collected from Gunung Jerai, Malaysia followed by the GC-FID and GC-MS analysis revealed the detection of a total of 47 constituents of which 28 (86.4%) from the stem and 31 (96.4%) constituents from the leaf. δ-Cadinene (17.4%), 1-epi-cubenol (11.8%), cyperotundone (9.0%), cis-cadin-4-en-7-ol (7.7%), τ-cadinol (7.1%) and α-cadinol (7.1%) were the principle constituents in the stem oil, whereas ß-caryophyllene (18.9%), bicyclogermacrene (18.6%) and trans-muurola-4(14),5-diene (9.8%) were the major constituents in the leaf oil. Among the identified constituents, three constituents namely 7-epi-α-selinene, junenol and cis-cadin-4-en-7-ol have not been found previously from Neolitsea oils. The stem and leaf oils were screened for their α-glucosidase inhibitory and antibacterial activities. Both oils displayed potential α-glucosidase inhibitory activity, while the stem oil possessed weak antibacterial activity against Bacillus subtilis.
Assuntos
Antibacterianos/farmacologia , Inibidores de Glicosídeo Hidrolases/farmacologia , Lauraceae/química , Óleos Voláteis/química , Antibacterianos/química , Avaliação Pré-Clínica de Medicamentos/métodos , Cromatografia Gasosa-Espectrometria de Massas , Inibidores de Glicosídeo Hidrolases/química , Malásia , Testes de Sensibilidade Microbiana , Óleos Voláteis/análise , Folhas de Planta/química , Caules de Planta/química , Sesquiterpenos Policíclicos , Sesquiterpenos/análise , Sesquiterpenos/farmacologia , Terpenos/análise , Terpenos/farmacologiaRESUMO
The chemical composition, antibacterial and α-glucosidase inhibitory activities of the essential oils obtained from hydrodistillation of the fresh stem and leaf of Neolitsea coccinea B. C. Stone are reported for the first time. GC and GC-MS analysis revealed the presence of 42 volatile compounds from the stem and leaf oils, accounting for 84.9% and 90.4%, respectively of the identified components. The principle compounds in the stem oil were δ-cadinene (21.2%), 1-epicubenol (11.3%) and cyperotundone (10.7%), while the main compounds in the leaf oil were selin-ll-en-4-α-ol (26.8%), bicyclogermacrene (12.6%), γ-eudesmol (7.1%), germacrene D (6.1%) and globulol (5.9%). The leaf oil demonstrated moderate to weak antibacterial activity towards Bacillus subtilis and Staphylococcus aureus with MIC values of 250 µg/mL and 500 µg/mL, respectively, whereas the stem oil posessed weak antibacterial activity against B. subtilis with a MIC value of 500 µg/mL. The stem and leaf oils showed significant α-glucosidase inhibitory activity with IC(50) values of 32.2 ± 0.8 µg/mL and 70.9 ± 1.1 µg/mL, respectively.
Assuntos
Antibacterianos , Inibidores de Glicosídeo Hidrolases , Lauraceae/química , Óleos Voláteis , Antibacterianos/química , Antibacterianos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/crescimento & desenvolvimento , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Testes de Sensibilidade Microbiana , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Folhas de Planta/química , Caules de Planta/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , alfa-Glucosidases/metabolismoRESUMO
The leaves of Gynotroches axillaris were chemically and biologically studied. Sequential extraction of the leaves using petroleum ether, chloroform, and methanol afforded three extracts. Purification of pet. ether extract yielded, squalene and ß-amyrin palmitate as the major compounds, together with palmitic acid and myristic acid as the minor components. The methanol extract yielded two flavonoids, quercitrin and epicatechin. The isolated compounds were characterized by MS, IR and NMR (1D and 2D). Anti-acetyl cholinesterase screening using TLC bio-autography assay showed that palmitic acid and myristic acid were the strongest inhibition with detection limit 1.14 and 1.28 µ/g/ 5 µL respectively. Antibacterial against Gram-positive and negative and antifungal activities exhibited that ß-amyrin palmitate was the strongest (450-225 µ/mL) against all the tested microbes. The tyrosinase inhibition assay of extracts and the pure compounds were screened against tyrosinase enzyme. The inhibition percentage (I%) of methanol extract against tyrosinase enzyme was stronger than the other extracts with value 68.4%. Quercitrin (59%) was found to be the highest in the tyrosinase inhibition activity amongst the pure compounds. To the best of our knowledge, this is first report on the phytochemicals, tyrosinase inhibition, anti-acetycholinesterase and antimicrobial activities of the leaves of G. axillaris.
Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Inibidores da Colinesterase/farmacologia , Monofenol Mono-Oxigenase/antagonistas & inibidores , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Rhizophoraceae/química , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antifúngicos/química , Antifúngicos/isolamento & purificação , Aspergillus niger/efeitos dos fármacos , Aspergillus niger/crescimento & desenvolvimento , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Candida/efeitos dos fármacos , Candida/crescimento & desenvolvimento , Inibidores da Colinesterase/química , Inibidores da Colinesterase/isolamento & purificação , Testes de Sensibilidade Microbiana , Estrutura Molecular , Monofenol Mono-Oxigenase/metabolismo , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Fitoterapia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Plantas Medicinais , Solventes/químicaRESUMO
Seven compounds were isolated from the n-hexane and chloroform extracts of the flowers and leaves of four Hornstedtia species and their structures were identified using spectroscopic techniques as 3,7,4'-trimethylkaempferol (1), 3,7-dimethylkaempferol (2), 7,4'-dimethylkaempferol (3), 3,5-dimethylkaempferol (4), 3-methylkaempferol (5), stigmast-4-en-3-one (6), and 6-hydroxy-stigmast-4-en-3-one (7). Compounds 1 to 7 were isolated from these species for the first time. They were assayed for free radical scavenging and α-glucosidase inhibition activities. The DPPH assay showed that 3-methylkaempferol (5) was the most potent antioxidant agent with an IC50 value 78.6 µM, followed by 7,4'-dimethylkaempferol (3) (IC50 = 86.1 µM). For α-glucosidase inhibition activity, 3-methylkaempferol (5) exhibited significant inhibitory activity with an IC50 value 21.0 µM. The present study revealed that Hornstedtia species have potential activities as antioxidant and α-glucosidase inhibitors.
Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Inibidores de Glicosídeo Hidrolases/farmacologia , Zingiberaceae/química , alfa-Glucosidases/metabolismo , Compostos de Bifenilo/química , Inibidores de Glicosídeo Hidrolases/química , Malásia , Picratos/química , Folhas de Planta/químicaRESUMO
The chemical composition of the essential oil and antioxidant and anti-inflammatory activities of the extracts from Piper miniatum were determined. GC and GC-MS analysis of the essential oil resulted in the identification of 64 components, accounting for 89.2% of the total. The major components were caryophyllene oxide (20.3%) and α-cubebene (10.4%). The antioxidant activity was evaluated by ß-carotene/linoleic acid bleaching, DPPH radical scavenging and total phenolic content. In the ß-carotene assay, the n-hexane extract showed the highest inhibition activity with 42.7%, while the oil gave 91.3%. The essential oil and extracts were tested for anti-inflammatory activity by using the TPA-induced mouse ear edema model and lipoxygenase assays. The essential oil exhibited significant activity in both models as an anti-inflammatory agent. The n-hexane extract showed strong activity with inhibition of 85.9% in the TPA-induced mouse ear edema model, while the chloroform extract showed the highest activity with 94.2% in the lipoxygenase assay.
Assuntos
Anti-Inflamatórios/administração & dosagem , Antioxidantes/administração & dosagem , Edema/tratamento farmacológico , Óleos Voláteis/administração & dosagem , Piper/química , Extratos Vegetais/administração & dosagem , Animais , Anti-Inflamatórios/química , Antioxidantes/química , Edema/imunologia , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Camundongos , Óleos Voláteis/química , Extratos Vegetais/químicaRESUMO
Some chalcones have been designed and synthesized using Claisen-Schmidt reactions as inhibitors of the ferredoxin and ferredoxin-NADP+ reductase interaction to pursue a new selective antimalaria agent. The synthesized compounds exhibited inhibition interactions between PfFd-PfFNR in the range of 10.94%-50%. The three strongest inhibition activities were shown by (E)-1-(4-aminophenyl)-3-(4-methoxyphenyl)prop-2-en-1-one (50%), (E)-1-(4-aminophenyl)-3-(2,4-dimethoxyphenyl)prop-2-en-1-one (38.16%), and (E)-1-(4-aminophenyl)-3-(2,3-dimethoxyphenyl)prop-2-en-1-one (31.58%). From the docking experiments we established that the amino group of the methoxyamino chlacone derivatives plays an important role in the inhibition activity by electrostatic interaction through salt bridges and that it forms more stable and better affinity complexes with FNR than with Fd.
Assuntos
Antimaláricos/síntese química , Chalcona/análogos & derivados , Chalcona/síntese química , Ferredoxina-NADP Redutase/antagonistas & inibidores , Ferredoxinas/antagonistas & inibidores , Proteínas de Protozoários/antagonistas & inibidores , Sítios de Ligação , Desenho de Fármacos , Ferredoxina-NADP Redutase/química , Ferredoxinas/química , Simulação de Acoplamento Molecular , Proteínas de Plantas/química , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/enzimologia , Estrutura Secundária de Proteína , Proteínas de Protozoários/químicaRESUMO
The chemical compositions and antimicrobial activity of the fresh rhizome and flower oils of Hornstedtia havilandii were studied. The components present were analyzed using GC and GC-MS. A total of forty-eight constituents were successfully identified from the flower and rhizome oils, representing 93.4% and 89.6%, respectively. The most abundant components of the flower oil were beta-pinene, (19.5%), beta-elemene, (10.0%), beta-cubebene, (6.2%), alpha-pinene, (5.6%), gamma-cadinene, (4.3%) and germacrene D, (3.3%), while alpha-copaene, (10.2%), beta-selinene, (8.4%), beta-elemene, (7.0%), gamma-cadinene, (6.9%), beta-cubebene, (5.3%) and germacrene D, (5.3%) were found as the main components of the rhizome oil. The essential oils were tested for antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria and yeasts. Both oils showed activity against the Gram-positive bacterium, Staphylococcus aureus, with moderate MIC values of 112.5 micro/mL, however, for Gram-negative bacteria, the flower oil showed weak antimicrobial activity with a MIC value of 225 microg/mL. Only very weak activity was shown against the yeasts Candida albicans and C. glabrata, with MIC values of 900-1800 microg/mL.
Assuntos
Anti-Infecciosos/análise , Óleos Voláteis/química , Zingiberaceae/química , Testes de Sensibilidade MicrobianaRESUMO
The stem bark extracts of Bauhinia rufescens Lam. (Fabaceae) yielded 6-methoxy-7-methyl-8-hydroxydibenz[b,f]oxepin, alpha-amyrin acetate, beta-sitosterol 3-O-beta-D-xylopyranoside, 4-(2'-Hydroxyphenethyl)-5-methoxy-2-methylphenol, menisdaurin and sequoyitol. Their structures were determined using spectroscopic methods and comparisons with the literature data. For the antimicrobial assay Gram-positive and Gram-negative bacterial and fungal strains were tested, while the tyrosinase inhibition assay utilized L-DOPA as a substrate for the tyrosinase enzyme. 6-Methoxy-7-methyl-8-hydroxydibenz[b,f]oxepin, a-amyrin acetate, beta-sitosterol 3-O-D-xylopyranoside, menisdaurin and sequoyitol showed weak to moderate activities with minimum inhibition concentration (MIC) values in the range of 112.5-900 microg/mL against all bacterial strains, while the MIC values for the fungal strains were in the range of 28.1-450 microg/mL. In the tyrosinase inhibition assay, a-amyrin acetate was found to be moderately active against tyrosinase with an inhibition of 62% at 0.1 mg/mL. This activity was lower than that of the positive control, kojic acid (85%).
Assuntos
Antibacterianos/isolamento & purificação , Bauhinia/química , Monofenol Mono-Oxigenase/antagonistas & inibidores , Estilbenos/isolamento & purificação , Antibacterianos/química , Glicosídeos/isolamento & purificação , Inositol/análogos & derivados , Inositol/isolamento & purificação , Testes de Sensibilidade Microbiana , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/isolamento & purificação , Oxepinas/isolamento & purificação , Casca de Planta/química , Caules de Planta/química , Plantas Medicinais/química , Estilbenos/químicaRESUMO
The essential oils from the leaves, pseudostems, rhizomes and fruits of Alpinia rafflesiana were isolated by hydrodistillation. The oils were analysed by capillary GC and GC-MS. The most abundant components in the leaf oil were trans-caryophyllene (32.61%), caryophyllene oxide (8.67%), (2E,6Z)-farnesol (4.91%) and alpha-terpineol (4.25%), while 1,8-cineole (32.25%), myrcene (13.63%), alpha-terpineol (9.90%) and trans-caryophyllene (9.80%) were the main constituents in the pseudostem oil. The rhizome constituted of tetracosane (42.61%), tau-cadinol (7.46%), alpha-terpineol (6.71%) were the major components, whereas tetracosane (13.39%), (2E,6E)-farnesol (7.31%), alpha-terpineol (8.51%) and caryophyllene oxide (8.05%) were the main components in the fruit oil. Antimicrobial assay revealed that all the essential oils showed moderate to weak inhibition against the tested microorganisms. The leaf oil was the most active and inhibited both S. aureus and E. coli with MIC values of 7.81 microg/mL and 15.6 microg/mL, respectively.
Assuntos
Alpinia/química , Anti-Infecciosos/análise , Óleos Voláteis/química , Testes de Sensibilidade a Antimicrobianos por Disco-DifusãoRESUMO
Hydrodistillation of the fresh leaves of Alpinia mutica afforded 0.005% colourless essential oil. GC and GC-MS analysis revealed the presence of 33 components accounting for 92.9% of the total oil, dominated by 20 sesquiterpenes (76.7%) and 10 monoterpenes (8.3%). The major constituent was found to be ß-sesquiphellandrene which was 29.2% of the total oil. Soxhlet extraction, followed by repeated column chromatography of the dried leaves yielded two phenolic compounds, identified as 5,6-dehydrokawain and aniba dimer A, together with one amide assigned as auranamide. The structures of these compounds were determined by using spectroscopic analysis. Antibacterial screening of the essential oil, the crude and isolated compounds showed weak to moderate inhibitory activity.
Assuntos
Alpinia/química , Folhas de Planta/química , Óleos de Plantas/química , Pironas/químicaRESUMO
The antioxidant activity and the total phenolic content, as well as the influence of petroleum ether, chloroform and methanol extracts from the leaves of Gynotroches axillaris, on microorganisms were studied. The total phenolic contents were evaluated by using Folin-Ciocalteu reagent and the obtained values ranged from 70.0 to 620 mg GAE/g. The efficiency of antioxidation, which was identified through the scavenging of free radical DPPH, exhibited that the highest IC50 was in the methanolic extract (44.7 µg/mL) as compared to the standard ascorbic acid (25.83 µg/mL) and to standard BHT (17.2 µg/mL). In vitro antimicrobial activity of extracts was tested against Gram-negative bacteria, Gram-positive bacteria and fungi. Methanol extract showed activity in the range (225-900 µg/mL) with both types, while petroleum ether and chloroform extracts were only active with Bacillus subtilis. The three extracts strongly inhibited all fungi with activity 225-450 µg/mL. The toxicity test against brine shrimps indicated that all extracts were non-toxic with LC50 value more than 1000 µg/mL. The finding of this study supports the safety of these extracts to be used in medical treatments.
RESUMO
Chemical investigation of the stem bark of Bauhinia rufescens resulted in the isolation of a new cyanoglucoside and menisdaurin from methanol extract and oxepin from petroleum ether extract. The isolated compounds were tested for their anti-inflammatory potentials based on the cyclooxygenase-2 enzyme (COX-2) model. Cyanoglucoside exhibited the highest activity among the compounds with an inhibition activity of 49.34 % at 100 µM (IC50 0.46 µM) compared to the positive control, indomethacin (79.20 %, IC50 0.24 µM).
RESUMO
The leaves of Polygonum minus were fractionated using an eluting solvent to evaluate the pharmacological mechanisms underlying the anti-ulcerogenic activity of P. minus. Different P. minus fractions were obtained and evaluated for their ulcer preventing capabilities using the ethanol induction method. In this study, Sprague Dawley rats weighing 150-200 g were used. Different parameters were estimated to identify the active fraction underlying the mechanism of the gastroprotective action of P. minus: the gastric mucus barrier, as well as superoxide dismutase, total hexosamine, and prostaglandin synthesis. Amongst the five fractions from the ethanolic extract of P. minus, the ethyl acetate:methanol 1:1 v/v fraction (F2) significantly (p < 0.005) exhibited better inhibition of ulcer lesions in a dose-dependent manner. In addition, rats pre-treated with F2 showed a significant elevation in superoxide dismutase (SOD), hexosamine and PGE2 levels in the stomach wall mucosa in a dose-dependent matter. Based on these results, the ethyl acetate:methanol 1:1 v/v fraction was considered to be the best fraction for mucous protection in the ethanol induction model. The mechanisms underlying this protection were attributed to the synthesis of antioxidants and PGE2.
Assuntos
Fármacos Gastrointestinais , Úlcera Péptica/tratamento farmacológico , Extratos Vegetais , Folhas de Planta/química , Polygonum/química , Animais , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Fármacos Gastrointestinais/química , Fármacos Gastrointestinais/farmacologia , Masculino , Úlcera Péptica/patologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ratos , Ratos Sprague-DawleyRESUMO
This study was designed to investigate the antioxidant and antimicrobial activities of the essential oils from Piper officinarum C. DC. GC and GC/MS analysis of the leaf and stem oils showed forty one components, representing 85.6% and 93.0% of the oil, respectively. The most abundant components in the leaf oil were beta-caryophyllene (11.2%), alpha-pinene (9.3%), sabinene (7.6%), beta-selinene (5.3%) and limonene (4.6%), while beta-caryophyllene (10.9%), alpha-phellandrene (9.3%), linalool (6.9%), limonene (6.7%) and alpha-pinene (5.0%) were the main components of the stem oil. The antioxidant activities were determined by using complementary tests: namely beta-carotene-linoleic acid, DPPH radical scavenging and total phenolic assays. The stems oil showed weak activity (IC50 = 777.4 microg/mL) in the DPPH system, but showed moderate lipid peroxidation inhibition in the beta-carotene-linoleic acid system (88.9 +/- 0.35%) compared with BHT (95.5 +/- 0.30%). Both oils showed weak activity against P. aeruginosa and E. coli with M IC values of 250 microg/mL.
Assuntos
Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Óleos Voláteis/farmacologia , Piper/química , Anti-Infecciosos/química , Antioxidantes/química , Compostos de Bifenilo/química , Escherichia coli/efeitos dos fármacos , Sequestradores de Radicais Livres/química , Fungos/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Indicadores e Reagentes , Ácido Linoleico/química , Peroxidação de Lipídeos/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Óleos Voláteis/química , Fenóis/química , Picratos/química , Folhas de Planta/química , Caules de Planta/química , Pseudomonas aeruginosa/efeitos dos fármacos , Solventes , beta Caroteno/químicaRESUMO
The essential oils obtained by hydrodistillation from the fresh leaf and stem of Piper porphyrophyllum N.E. Br. were analyzed by GC and GC/MS. Thirty four constituents were identified in the leaf oil, while thirty eight constituents were identified in the stems oil. The most abundant components in the leaf oil included bicyclogermacrene (14.7 %), α-copaene (13.2 %) and ß-phellandrene (9.5 %) while sabinene (15.5 %), bicyclogermacrene (12.3 %) and α-copaene (8.1 %) were the main constituents in the stem oil. The evaluation of antibacterial activity by using micro-dilution method revealed that both oils were moderately active against all the Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria (Pseudomonas aeruginosa, Pseudomonas putida and Escherichia coli) with minimum inhibitory concentration (MIC) values in the range 125-1000 µg/ml.
RESUMO
Chemical composition, antioxidant and antimicrobial activities of the fresh leaves and stems oils of Piper caninum were investigated. A total of forty eight constituents were identified in the leaves (77.9%) and stems (87.0%) oil which were characterized by high proportions of phenylpropanoid, safrole with 17.1% for leaves and 25.5% for stems oil. Antioxidant activities were evaluated by using ß-carotene/linoleic acid bleaching, DPPH radical scavenging and total phenolic content. Stems oil showed the highest inhibitory activity towards lipid peroxidation (114.9 ± 0.9%), compared to BHT (95.5 ± 0.5%), while leaves oil showed significant total phenolic content (27.4 ± 0.5 mg GA/g) equivalent to gallic acid. However, the essential oils showed weak activity towards DPPH free-radical scavenging. Evaluation of antimicrobial activity revealed that both oils exhibited strong activity against all bacteria strains with MIC values in the range 62.5 to 250 µg/mL, but weak activity against fungal strains. These findings suggest that the essential oils can be used as antioxidant and antimicrobial agents for therapeutic, nutraceutical industries and food manufactures.