Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
J Econ Entomol ; 116(2): 447-455, 2023 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-36708054

RESUMO

The negative side effects of synthetic pesticides have drawn attention to the need for environmentally friendly agents to control arthropod pests. To identify promising candidates as botanical pesticides, we investigated the acaricidal and insecticidal activities of 44 plant-derived essential oils (EOs) against Tetranychus urticae Koch and Myzus persicae Sulzer. Among the tested EOs, Tasmannia lanceolata (Poir.) A.C.Sm. (Tasmanian pepper) essential oil (TPEO) exhibited strong acaricidal and insecticidal activity. Mortality rates of 100% and 71.4% against T. urticae and M. persicae, respectively, were observed with TPEO at a concentration of 2 mg/ml. Polygodial was determined to be the primary active component after bioassay-guided isolation of TPEO using silica gel open-column chromatography, gas chromatography, and gas chromatography-mass spectrometry. Polygodial demonstrated acaricidal activity against T. urticae with mortality rates of 100%, 100%, 61.9%, and 61.6% at concentrations of 1, 0.5, 0.25, and 0.125 mg/ml, respectively. Insecticidal activity against M. persicae was also evident, with mortality rates of 88.5%, 85.0%, 46.7%, and 43.3% at respective concentrations of 1, 0.5, 0.25, and 0.125 mg/ml. Insecticidal and acaricidal activities of TPEO were greater than those of Eungjinssag, a commercially available organic agricultural material for controlling mites and aphids in the Republic of Korea. These findings suggest that TPEO is a promising candidate for mites and aphids control.


Assuntos
Acaricidas , Afídeos , Inseticidas , Magnoliopsida , Ácaros , Óleos Voláteis , Praguicidas , Tetranychidae , Animais , Óleos Voláteis/química , Acaricidas/farmacologia , Inseticidas/farmacologia , Winteraceae , Óleos de Plantas/farmacologia , Praguicidas/farmacologia
2.
Biomed Pharmacother ; 154: 113546, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35988426

RESUMO

The overexpression of antiapoptotic members (BCL-2, BCL-xL, MCL-1, etc.) of the BCL-2 family contributes to tumor development and resistance to chemotherapy or radiotherapy. Synthetic inhibitors targeting these proteins have been developed, and some hematological malignancies are now widely treated with a BCL-2 inhibitor (venetoclax). However, acquired resistance to venetoclax or chemotherapy drugs due to an upregulation of MCL-1 has been observed, rendering MCL-1 an attractive new target for treatment. Six MCL-1 inhibitors (S64315, AZD-5991, AMG-176, AMG-397, ABBV-467 and PRT1419) have been evaluated in clinical trials since 2016, but some were affected by safety issues and none are currently used clinically. There is, therefore, still a need for alternative molecules. We previously described two drimane derivatives as the first covalent BH3 mimetics targeting MCL-1. Here, we described the characterization and biological efficacy of one of these compounds (NA1-115-7), isolated from Zygogynum pancheri, a plant belonging to the Winteraceae family. NA1-115-7 specifically induced the apoptosis of MCL-1-dependent tumor cells, with two hours of treatment sufficient to trigger cell death. The treatment of lymphoma cells with NA1-115-7 stabilized MCL-1, disrupted its interactions with BAK, and rapidly induced apoptosis through a BAK- and BAX-mediated process. Importantly, a similar treatment with NA1-115-7 was not toxic to erythrocytes, peripheral blood mononuclear cells, platelets, or cardiomyocytes. These results highlight the potential of natural products for use as specific BH3 mimetics non-toxic to normal cells, and they suggest that NA1-115-7 may be a promising tool for use in cancer treatment.


Assuntos
Antineoplásicos , Neoplasias Hematológicas , Antineoplásicos/farmacologia , Apoptose , Compostos Bicíclicos Heterocíclicos com Pontes , Linhagem Celular Tumoral , Neoplasias Hematológicas/tratamento farmacológico , Humanos , Leucócitos Mononucleares/metabolismo , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Miócitos Cardíacos/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Sulfonamidas , Winteraceae/metabolismo , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteína bcl-X/metabolismo
3.
J Nat Prod ; 83(12): 3698-3705, 2020 12 24.
Artigo em Inglês | MEDLINE | ID: mdl-33232149

RESUMO

Drimys brasiliensis (Winteraceae) has been investigated in traditional medicine for its anti-inflammatory properties to treat gastric ulcers and allergic and respiratory system diseases as well as for cancer treatment. In this work, we investigate the ability of the sesquiterpene polygodial, isolated from D. brasiliensis stem barks, to modulate the chronic inflammatory response induced by polyester-polyurethane sponge implants in C57BL/6J mice. Daily treatment with polygodial inhibited the macrophage content in the implants as determined by the activity of the N-acetyl-ß-d-glucosaminidase enzyme as well as decreased the levels of CXCL1/KC and CCL2/JE/MCP-1 pro-inflammatory chemokines and the presence of mast cells along the formed fibrovascular tissue. Similarly, the deposition of a new extracellular matrix (total collagen and type I and III collagen fibers) as well as the production of the TGF-ß1 cytokine were attenuated in implants treated with polygodial, showing for the first time its antifibrogenic capacity. The hemoglobin content, the number of newly formed vessels, and the levels of VEGF cytokine, which were used as parameters for the assessment of the neovascularization of the implants, did not change after treatment with polygodial. The anti-inflammatory and antifibrogenic effects of polygodial over the components of the granulation tissue induced by the sponge implant indicate a therapeutic potential for the treatment of inflammatory diseases associated with the development of fibrovascular tissue.


Assuntos
Regulação para Baixo , Drimys/química , Inflamação/prevenção & controle , Sesquiterpenos/isolamento & purificação , Winteraceae/química , Animais , Fibrose/prevenção & controle , Camundongos , Camundongos Endogâmicos C57BL
4.
Chem Biol Interact ; 330: 109167, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32603660

RESUMO

Recently, it has been shown that drimane-type sesquiterpenoids isolated from Zygogynum pancheri, a species native to New Caledonia, possessed significant α-amylase inhibitory activities. To further explore their antidiabetic potential, we investigated the effect of 1ß-O-(E-cinnamoyl)-6α-hydroxy-9epi-polygodial (D) and 1ß-E-O-p-methoxycinnamoyl-bemadienolide (L), two of the most active compounds of the series, on diabetic model rats. Compounds D and L (2 mg kg/day) were daily and orally administrated for 30 days to streptozotocin (STZ) (150 mg/kg) induced male diabetic Wistar rats. Animals were allocated into five groups of six rats. Comparatively to diabetic rats, treatments with D and L compounds were able to significantly (P < 0.05) decrease Fasting Blood Glucose (FBG) (70.15%, 71.02%), serum total cholesterol (46.27% and 39.38%), triglycerides (56.60% and 58.15%), creatinine (37.31% and 36.49%) and uric acid levels (67.76% and 69.68%), respectively. Compounds D and L also restored the altered plasma enzyme (aspartate aminotransferase, AST (47.83% and 43.20%), alanine aminotransferase, ALT (49.76% and 48.35%, alkaline phosphatase, ALP (72.78% and 73.21%)) and lactate dehydrogenase, LDH (47.95% and 53.93%) levels to near normal, respectively. Administration of Glymepiride, significantly (p < 0.05) reduced FBG (73.94%) in STZ induced diabetic rats. Additionally, the compounds D and L exhibited inhibitory effects in vivo on lipase activity of diabetic rats (54.83% and 52.25%), respectively. The outcomes of this study suggested that these two drimanes could be considered as efficient hypoglycemic, hypolipidemic and antiobesity agents for diabetes management and its complications.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Fitoterapia/métodos , Extratos Vegetais/farmacologia , Sesquiterpenos Policíclicos/isolamento & purificação , Animais , Fármacos Antiobesidade/isolamento & purificação , Fármacos Antiobesidade/farmacologia , Hipoglicemiantes/isolamento & purificação , Hipoglicemiantes/farmacologia , Hipolipemiantes/isolamento & purificação , Hipolipemiantes/farmacologia , Masculino , Nova Caledônia , Extratos Vegetais/química , Sesquiterpenos Policíclicos/farmacologia , Ratos , Ratos Wistar , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Winteraceae/química
5.
Mater Sci Eng C Mater Biol Appl ; 112: 110922, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32409072

RESUMO

Green nanotechnology plays a significant role in developing effective treatment strategies for numerous diseases. The biological synthesis of metal nanoparticles (M-NPs) possesses suitable alternatives than chemical techniques. Using plant extract to synthesis M-NPs is an eco-friendly, non-toxic, and cost-effective that are suitable for biological applications and efforts are directed to explore the efficacy of these materials in cancer management. In this study, gold nanoparticles (Au-NPs) were synthesised by following a one-step green synthesis, a reaction between HAuCl4 and biological molecules present in Tasmannia lanceolata leaf extract as a sole agent for both reduction and stabilisation. The characterisation techniques confirmed the successful synthesis of Au-NPs. TEM photograph revealed spherical shape nanoparticles with an average size of 7.10 ± 0.66 nm. The in-vitro cytotoxicity of Au-NPs was performed by analysing the percentage inhibition of cell viability using Resazurin assay on human liver cancer (HepG2), melanoma cancer (MM418 C1) and breast cancer (MCF-7) cell lines and compared with Au-NPs synthesised by using Backhousia citriodora leaf extract. The results showed that biosynthesised Au-NPs displayed greater inhibitory activity towards MCF-7 cancer cells proliferation compared to HepG2 and MM418 cancer cells. In addition, synthesised Au-NPs@ Tasmannia lanceolata leaf extract indicated higher inhibitory activity towards cancer cells compared to Au-NPs@ Backhousia citriodora leaf extract.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Myrtaceae/química , Extratos Vegetais/química , Winteraceae/química , Austrália , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Química Verde , Humanos , Nanopartículas Metálicas/toxicidade , Myrtaceae/metabolismo , Tamanho da Partícula , Folhas de Planta/química , Folhas de Planta/metabolismo , Winteraceae/metabolismo
6.
J Agric Food Chem ; 68(1): 315-322, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31851503

RESUMO

This study assesses whether the distinct altitudinal cline in leaf morphology (decreased leaf width and length with increased altitude) in Tasmanian mountain pepper (Tasmannia lanceolata) is associated with changes in the leaf chemistry of wild populations from different ecological landscapes and altitudes. The presence of distinct pungent drimane sesquiterpenoid chemotypes was identified: subalpine woodland and wet sclerophyll forest chemotypes. Isolation studies and analysis of extracts revealed that wet sclerophyll forest T. lanceolata populations featured polygodial as the principal terpenoid, with profiles similar to the commercial cultivars sampled. In contrast, the subalpine woodland populations contained the drimane sesquiterpenoids 1ß-acetoxy-9-deoxyisomuzigadial and 3ß-acetoxydrimenin and the conspicuous absence of the pungent principle polygodial.


Assuntos
Compostos Fitoquímicos/química , Extratos Vegetais/química , Winteraceae/química , Altitude , Folhas de Planta/química , Sesquiterpenos/química , Tasmânia , Terpenos/química
7.
J Mycol Med ; 29(4): 331-344, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31248775

RESUMO

OBJECTIVE: Syzygium australe (H.L. Wnddl. ex. Link) B. Hyland, Syzygium luehmannii (F. Muell.) L.A.S. Johnson, Syzygium jambos L. (Alston), Terminalia ferdinandiana Exell. and Tasmannia lanceolata (Poir.) A.C.Sm. are used in traditional Australian Aboriginal and Asian healing systems to treat a variety of pathogenic diseases including fungal skin infections, yet they are yet to be examined for the ability to inhibit the growth of human dermatophytes. MATERIALS AND METHODS: The fungal growth inhibitory activity of extracts produced from selected Australian and Asian plants was assessed against a panel of human dermatophytes by standard disc diffusion and liquid dilution MIC methods. The toxicity of the extracts was evaluated by Artemia lethality and MTS HDF cell viability assays. The phytochemistry of the most promising extracts were examined by GC-MS headspace analysis and some interesting compounds were highlighted. RESULTS: The aqueous and methanolic extracts of all plant species were good antifungal agents, inhibiting the growth of all of the dematophytes tested. The methanolic S. australe (SA) and S. luehmannii (SL) extracts were particularly potent fungal growth inhibitors. MIC values of 39 and 53µg/mL were recorded for the methanolic SL fruit extract against T. mentagrophytes and T. rubrum respectively. Similar MICs were also noted for the methanolic SL leaf extract (88 and 106µg/mL respectively). The methanolic SL leaf extract was a particularly good fungal growth inhibitor, with MIC values≤100µg/mL against the reference C. albicans strain (96µg/mL), E. floccosum (53µg/mL), and T. mentagrophytes (88µg/mL). This extract also produced MICs≤200µg/mL against all other fungal species/strains tested. Similarly good activity was seen for the methanolic S. australe leaf and fruit extracts, as well as the S. lehmannii fruit and S. jambos leaf extracts, with MIC values 100-500µg/mL. Interestingly, these extracts had low toxicity and high therapeutic indices, indicating their suitability for clinical use. GC-MS headspace analysis highlighted several monoterpenoids and sesquiterpenoids in the methanolic SA and SL extracts. T. ferdinandiana and T. lanceolata extracts also had promising antifungal activity, albeit with substantially higher MICs. CONCLUSION: Whilst multiple extracts inhibited fungal growth, the methanolic S. australe and S. luehmannii leaf extracts and the S. luehmannii fruit extracts showed particularly potent activity against each of these dermatophytes, indicating that they are promising leads for the development of anti-dermatophytic therapeutics.


Assuntos
Antifúngicos/farmacologia , Arthrodermataceae/efeitos dos fármacos , Arthrodermataceae/crescimento & desenvolvimento , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Arthrodermataceae/patogenicidade , Ásia , Austrália , Dermatomicoses/tratamento farmacológico , Frutas/química , Humanos , Medicina Tradicional do Leste Asiático , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Folhas de Planta/química , Syzygium/química , Terminalia/química , Winteraceae/química
8.
J Agric Food Chem ; 65(28): 5700-5712, 2017 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-28657737

RESUMO

Sensory-guided fractionation of extracts of Tasmanian pepper berries revealed 20 drimane sesquiterpens, among which polygodial, warburganal, and 1ß-acetoxy-9-deoxy-isomuzigadial exhibited the lowest pungency threshold concentrations on the tongue surface (0.6-2.8 nmol/cm2) and elicited a dose-dependent calcium influx into mTRPA1 expressing CHO cells with the lowest EC50 values (4.5 ± 1.0 to 16.7 ± 7.5 µmol/L) and a good correlation to oral pungency thresholds (R2 = 0.986, linear regression). Calcium imaging assays demonstrated these chemosensates to induce a calcium influx into cultured trigeminal neurons prepared from wildtype (TRPA1+/+) mice, whereas no calcium influx was observed in neurons from TRPA1 knockout mice (TRPA1-/-), thus confirming the α,ß-unsaturated 1,4-dialdehyde structure to be the required structural motif for a low oral puncency thresholds and activation of the Transient Receptor Potential Channel A1 (TRPA1). Time-resolved NMR experiments confirmed the pungency mediating mechanism for electrophilic drimane sesquiterpene dialdehydes to be different from that found for other electrophilic pungent agents like isothiocyanates, which have been shown to undergo a covalent binding with cysteine residues in TRPA1. Instead, the high-impact chemosensates polygodial, warburganal, and 1ß-acetoxy-9-deoxy-isomuzigadial showed immediate reactivity with the ε-amino group of lysine side chains to give pyrrole-type conjugates, thus showing evidence for TRPA1 activation by covalent lysine modification.


Assuntos
Canais de Cálcio/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Extratos Vegetais/química , Sesquiterpenos/química , Paladar , Canais de Potencial de Receptor Transitório/metabolismo , Winteraceae/química , Adulto , Animais , Células CHO , Cálcio/metabolismo , Canais de Cálcio/genética , Cricetulus , Feminino , Humanos , Masculino , Camundongos , Camundongos Knockout , Proteínas do Tecido Nervoso/genética , Extratos Vegetais/metabolismo , Sesquiterpenos Policíclicos , Sesquiterpenos/metabolismo , Canal de Cátion TRPA1 , Canais de Potencial de Receptor Transitório/genética , Winteraceae/metabolismo , Adulto Jovem
9.
Org Biomol Chem ; 13(46): 11200-7, 2015 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-26377594

RESUMO

Polygodial, a valuable sesquiterpene dialdehyde featuring an epimerizable stereocenter was efficiently extracted and isolated in gram-scale quantities (3.3% w/w) from Tasmannia lanceolata (Tasmanian native pepper) via a recently developed rapid pressurised hot water extraction (PHWE) technique that utilises an unmodified household espresso machine. This method was compared to the maceration of T. lanceolata under a range of conditions. Polygodial was used to achieve semi-syntheses of closely related sesquiterpene natural products drimendiol, (-)-drimenol, (+)-euryfuran, and some non-natural derivatives.


Assuntos
Produtos Biológicos/síntese química , Furanos/síntese química , Sesquiterpenos/isolamento & purificação , Terpenos/síntese química , Winteraceae/química , Produtos Biológicos/química , Furanos/química , Sesquiterpenos Policíclicos , Sesquiterpenos/síntese química , Sesquiterpenos/química , Terpenos/química
10.
Tree Physiol ; 35(4): 387-99, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25716877

RESUMO

Trees from tropical montane cloud forest (TMCF) display very dynamic patterns of water use. They are capable of downwards water transport towards the soil during leaf-wetting events, likely a consequence of foliar water uptake (FWU), as well as high rates of night-time transpiration (Enight) during drier nights. These two processes might represent important sources of water losses and gains to the plant, but little is known about the environmental factors controlling these water fluxes. We evaluated how contrasting atmospheric and soil water conditions control diurnal, nocturnal and seasonal dynamics of sap flow in Drimys brasiliensis (Miers), a common Neotropical cloud forest species. We monitored the seasonal variation of soil water content, micrometeorological conditions and sap flow of D. brasiliensis trees in the field during wet and dry seasons. We also conducted a greenhouse experiment exposing D. brasiliensis saplings under contrasting soil water conditions to deuterium-labelled fog water. We found that during the night D. brasiliensis possesses heightened stomatal sensitivity to soil drought and vapour pressure deficit, which reduces night-time water loss. Leaf-wetting events had a strong suppressive effect on tree transpiration (E). Foliar water uptake increased in magnitude with drier soil and during longer leaf-wetting events. The difference between diurnal and nocturnal stomatal behaviour in D. brasiliensis could be attributed to an optimization of carbon gain when leaves are dry, as well as minimization of nocturnal water loss. The leaf-wetting events on the other hand seem important to D. brasiliensis water balance, especially during soil droughts, both by suppressing tree transpiration (E) and as a small additional water supply through FWU. Our results suggest that decreases in leaf-wetting events in TMCF might increase D. brasiliensis water loss and decrease its water gains, which could compromise its ecophysiological performance and survival during dry periods.


Assuntos
Atmosfera , Drimys/fisiologia , Ecossistema , Folhas de Planta/fisiologia , Solo , Árvores/fisiologia , Água/fisiologia , Carbono/metabolismo , Secas , Florestas , Fotossíntese , Caules de Planta , Transpiração Vegetal , Estações do Ano , Clima Tropical , Winteraceae , Xilema/fisiologia
11.
J Asian Nat Prod Res ; 16(12): 1132-8, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25034255

RESUMO

One new sesquiterpenoid (5R(*),8R(*),9R(*),10R(*))-cinnamolide (8), and seven known compounds, 5-hydroxy-7-methoxyflavonone (1), 8-hydroxy-3-(4'-hydroxyphenyl)-6,7-(2″,2″-dimethylchromene)-tetralone (2), 8-hydroxy-3-(3',4'-dihydroxyphenyl)-6,7-(2″,2″-dimethylchromene)-tetralone (3), 1ß-E-O-p-methoxycinnamoyl-bemadienolide (4), 1ß-O-(E-cinnamoyl)-6α-hydroxy-9-epi-polygodial (5), 1ß-O-(E-cinnamoyl)-6α-hydroxypolygodial (6), and 1ß-O-E-cinnamoylpolygodial (7) were isolated from the ethyl acetate extract of barks of Zygogynum pancheri subsp. arrhantum (Winteraceae). The structures of these molecules were assigned predominantly based on spectral data. The structure of compound 8 was confirmed by X-ray crystallographic analysis. Compounds 2 and 3 exhibited significant antioxidant activity, whereas compounds 1 and 4-7 showed significant α-amylase inhibitory activity.


Assuntos
Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Winteraceae/química , alfa-Amilases/antagonistas & inibidores , Antioxidantes/química , Cristalografia por Raios X , Conformação Molecular , Estrutura Molecular , Oxirredução , Sesquiterpenos Policíclicos , Sesquiterpenos/química
12.
J Agric Food Chem ; 61(24): 5738-45, 2013 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-23682630

RESUMO

Lemon myrtle, anise myrtle, and Tasmanian pepper leaf are commercial Australian native herbs with a high volatile or essential oil content. Packaging of the herbs in high- or low-density polyethylene (HDPE and LDPE) has proven to be ineffective in preventing a significant loss of volatile components on storage. This study investigates and compares the effectiveness of alternate high-barrier property packaging materials, namely, polyvinylidene chloride coated polyethylene terephthalate/casted polypropylene (PVDC coated PET/CPP) and polyethylene terephthalate/polyethylene terephthalate/aluminum foil/linear low-density polyethylene (PET/PET/Foil/LLDPE), in prevention of volatile compound loss from the three native herbs stored at ambient temperature for 6 months. Concentrations of major volatiles were monitored using gas chromatography-mass spectrometry (GC-MS) techniques. After 6 months of storage, the greatest loss of volatiles from lemon myrtle was observed in traditional LDPE packaging (87% loss) followed by storage in PVDC coated PET/CPP (58% loss) and PET/PET/Foil/LLDPE (loss of 23%). The volatile loss from anise myrtle and Tasmanian pepper leaf stored in PVDC coated PET/CPP and PET/PET/Foil/LLDPE packaging was <30%. This study clearly indicates the importance of selecting the correct packaging material to retain the quality of herbs with high volatile content.


Assuntos
Embalagem de Alimentos , Armazenamento de Alimentos , Myrtaceae/química , Folhas de Planta/química , Caules de Planta/química , Compostos Orgânicos Voláteis/análise , Winteraceae/química , Austrália , Condimentos/análise , Dieta/etnologia , Manipulação de Alimentos , Qualidade dos Alimentos , Alimentos em Conserva/análise , Humanos , Myrtaceae/metabolismo , Folhas de Planta/metabolismo , Caules de Planta/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Winteraceae/metabolismo
13.
J Nat Prod ; 76(4): 710-4, 2013 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-23517126

RESUMO

Bioassay-guided phytochemical investigation of Zygogynum calothyrsum using the human colon carcinoma cell lines COLO205 and KM12 led to the isolation of three new drimane-type sesquiterpenoids, 1ß-p-hydroxy-E-cinnamoyldrimeninol (1), 1ß-p-hydroxy-E-cinnamoyl-5α-hydroxydrimeninol (2), and methyl ether of 1ß-p-hydroxy-E-cinnamoyl-12α-methoxydrimeninol (3). Also isolated was the known 1ß-p-coumaroyloxypolygodial (4) together with two new tetralones, 3'-deoxyisozygolone A (5) and calothyrlone A (9), three known tetralones, isozygolone A (6), zygolone A (7), and 4'-O-methylzygolone A (8), and a known cinnamolide (10). Compounds 1, 7, and 8 demonstrated higher cytotoxicity against COLO205 (GI50 18, 17, and 11 µM, respectively) and KM12 (GI50 14, 14, and 17 µM, respectively) than the other compounds.


Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Neoplasias do Colo/tratamento farmacológico , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Tetralonas/isolamento & purificação , Tetralonas/farmacologia , Winteraceae/química , Antineoplásicos Fitogênicos/química , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Sesquiterpenos/química , Estereoisomerismo , Tetralonas/química
14.
Oecologia ; 173(2): 375-85, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23529370

RESUMO

The definition of photosynthetically active radiation (Q) as the visible waveband (λ 400-700 nm) is a core assumption of much of modern plant biology and global models of carbon and water fluxes. On the other hand, much research has focused on potential mutation and damage to leaves caused by ultraviolet (UV) radiation (280-400 nm), and anatomical and physiological adaptations that help avoid such damage. Even so, plant responses to UV-A are poorly described and, until now, photosynthetic utilization of UV-A has not been elucidated under full light conditions in the field. We found that the UV-A content of sunlight increased photosynthetic rates in situ by 12% in Pimelea ligustrina Labill., a common and indigenous woody shrub of alpine ecosystems of the Southern Hemisphere. Compared to companion shrubs, UV-A-induced photosynthesis in P. ligustrina resulted from reduced physical and chemical capacities to screen UV-A at the leaf surface (illustrated by a lack of cuticle and reduced phenol index) and the resulting ability of UV-A to excite chlorophyll (Chl) a directly, and via energy provided by the carotenoid lutein. A screening of 55 additional sub-alpine species showed that 47% of the plant taxa also display Chl a fluorescence under UV-A. If Chl a fluorescence indicates potential for photosynthetic gain, continued exclusion of UV-A from definitions of Q in this ecosystem could result in underestimates of measured and modeled rates of photosynthesis and miscalculation of potential for carbon sequestration. We suggest that carbon gain for alpine environs across the globe could be similarly underestimated given that UV-A radiation increases with altitude and that the frequently dominant herb and grass life-forms often transmit UV-A through the epidermis.


Assuntos
Asteraceae/metabolismo , Fotossíntese , Thymelaeaceae/metabolismo , Raios Ultravioleta , Winteraceae/metabolismo , Asteraceae/anatomia & histologia , Asteraceae/efeitos da radiação , Clorofila/metabolismo , New South Wales , Folhas de Planta/anatomia & histologia , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Espectrometria de Fluorescência , Thymelaeaceae/anatomia & histologia , Thymelaeaceae/efeitos da radiação , Winteraceae/anatomia & histologia , Winteraceae/efeitos da radiação
15.
Food Chem ; 134(2): 1011-9, 2012 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-23107721

RESUMO

Polyphenolic-rich fractions obtained from three native Australian herbs: Tasmannia pepper leaf, anise myrtle and lemon myrtle were characterised with regards to their composition, antioxidant capacities and inhibitory activities against α-glucosidase, pancreatic lipase and angiotensin I-converting enzyme, using in vitro models. Ellagic acid and derivatives were the dominant compounds of anise myrtle and lemon myrtle fractions, accompanied by flavonoids (catechin, myricetin, hesperetin, and quercetin). Tasmannia pepper leaf fraction comprised chlorogenic acid and quercetin derivatives, exhibited the highest oxygen radical absorbance capacity and effectively inhibited α-glucosidase (IC(50): 0.83 mg/ml) and pancreatic lipase (IC(50): 0.60 mg/ml). Anise myrtle and lemon myrtle fractions had pronounced α-glucosidase-inhibitory activities (IC(50): 0.30 and 0.13 mg/ml, respectively) and were less effective against lipase. Enzyme-inhibitory activities showed various levels of correlation with the levels of total phenolics and antioxidant capacities, indicating a specificity of individual phenolic compounds present in the isolated fractions to complex with proteins.


Assuntos
Inibidores Enzimáticos/química , Inibidores de Glicosídeo Hidrolases , Lipase/antagonistas & inibidores , Síndrome Metabólica/enzimologia , Myrtaceae/química , Extratos Vegetais/química , Polifenóis/química , Syzygium/química , Winteraceae/química , Animais , Austrália , Inibidores Enzimáticos/farmacologia , Humanos , Cinética , Lipase/metabolismo , Myrtus , Peptidil Dipeptidase A/metabolismo , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Ratos , Suínos , alfa-Glucosidases/metabolismo
16.
Nat Prod Commun ; 7(6): 685-92, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22816285

RESUMO

The liverwort, Porella vernicosa complex produces a very hot tasting polygodial, a drimane-type sesquiterpene dialdehyde. The same compound has been isolated from two ferns, Thelypteris hispidula and Blechnum fluviatile, as well as from the higher plants Polygonum hydropiper, P. hydropiper f. purpurascens (Polygonaceae), Cinnamosma, Caspicodendron, Canella and Warburgia species (Canellaceae), and Pseudowintera colorata, Tasmannia lanceolata, Drimys and Zygogynum species (Winteraceae). In addition, the liverworts and higher plants which elaborate polygodial and its related pungent drimane dials contain a small amount of alpha-tocopherol, gamma-tocopherol or delta-tocotrienol. The present paper gives the results of a comparative study on the drimane-type sesquiterpenoids in some liverworts, ferns and higher plants, and the role of tocopherols in these plant groups.


Assuntos
Gleiquênias/metabolismo , Hepatófitas/metabolismo , Polygonaceae/metabolismo , Sesquiterpenos/metabolismo , Tocoferóis/metabolismo , Winteraceae/metabolismo , Estrutura Molecular , Sesquiterpenos Policíclicos , Sesquiterpenos/química
17.
New Phytol ; 193(1): 229-240, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21995496

RESUMO

• The lack of extant lianescent vessel-less seed plants supports a hypothesis that liana evolution requires large-diameter xylem conduits. Here, we demonstrate an unusual example of a lianoid vessel-less angiosperm, Tasmannia cordata (Winteraceae), from New Guinea. • Wood mechanical, hydraulic and structural measurements were used to determine how T. cordata climbs and to test for ecophysiological shifts related to liana evolution vs 13 free-standing congeners. • The tracheid-based wood of T. cordata furnished low hydraulic capacity compared with that of vessel-bearing lianas. In comparison with most nonclimbing relatives, T. cordata possessed lower photosynthetic rates and leaf and stem hydraulic capacities. However, T. cordata exhibited a two- to five-fold greater wood elastic modulus than its relatives. • Tasmannia cordata provides an unusual example of angiosperm liana evolution uncoupled from xylem conduit gigantism, as well as high plasticity and cell type diversity in vascular development. Because T. cordata lacks vessels, our results suggest that a key limitation for a vessel-less liana is that strong and low hydraulically conductive wood is required to meet the mechanical demands of lianescence.


Assuntos
Evolução Biológica , Feixe Vascular de Plantas/anatomia & histologia , Winteraceae/anatomia & histologia , Winteraceae/fisiologia , Madeira/anatomia & histologia , Madeira/fisiologia , Austrália , Fenômenos Biomecânicos/efeitos da radiação , Luz , Microfibrilas/química , Papua Nova Guiné , Fotossíntese/efeitos da radiação , Folhas de Planta/anatomia & histologia , Folhas de Planta/fisiologia , Folhas de Planta/efeitos da radiação , Feixe Vascular de Plantas/fisiologia , Feixe Vascular de Plantas/efeitos da radiação , Winteraceae/crescimento & desenvolvimento , Winteraceae/efeitos da radiação , Madeira/crescimento & desenvolvimento , Madeira/efeitos da radiação , Xilema/anatomia & histologia , Xilema/crescimento & desenvolvimento , Xilema/efeitos da radiação
18.
J Food Sci ; 76(3): C447-53, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21535813

RESUMO

UNLABELLED: Davidson's plum (Davidsonia pruriens, F. Muell.), a native to Australian rainforests, large, crimson-red fruit, which superficially resembles plum, has been commercially cultivated in Australia since 1990s. The current production volume exceeds market demands therefore this study was designed to evaluate the suitability of Davidson's plum extract as a source of anthocyanin-based food colorant. The stability of the Davidson's plum extract towards heat treatment at 95 °C was higher than that of commercial mulberry colorant, but inferior to colorants derived from red cabbage and purple sweetpotato. An addition of a variety of phenolic acids significantly increased color intensity indicating the formation of copigmentation complexes. Commercial chlorogenic acid as well as extract from a native Australian herb rich in chlorogenic acid, Tasmannia pepper leaf (Tasmannia lanceolata, R. Br.), were both tested in model soft drink solutions subjected to light irradiation and heat treatment. In both cases, the addition of the copigment resulted in a lasting increase in color intensity. In conclusion, Davidson's plum extract can successfully be utilized as a source of natural food color. Extract from Tasmania pepper leaf can be used as a co-pigment for Davidson's plum anthocyanins. PRACTICAL APPLICATION: The color properties of an anthocyanin colorant derived from the native Australian fruit Davidson's plum are comparable to those of mulberry, which is currently applied as a food colorant in Australian food products. Utilization of Davidson's plum fruit as a source of natural color will allow the industry to increase the range of natural pigments and will create new opportunities for the emerging native food industry.


Assuntos
Antocianinas/análise , Gleiquênias/química , Corantes de Alimentos/análise , Frutas/química , Pigmentos Biológicos/análise , Folhas de Planta/química , Winteraceae/química , Antocianinas/química , Antocianinas/efeitos da radiação , Bebidas Gaseificadas/análise , Cinamatos/análise , Cinamatos/química , Aditivos Alimentares/química , Corantes de Alimentos/química , Corantes de Alimentos/efeitos da radiação , Temperatura Alta/efeitos adversos , Cinética , Luz/efeitos adversos , Concentração Osmolar , Fenóis/análise , Fenóis/química , Pigmentação , Pigmentos Biológicos/química , Pigmentos Biológicos/efeitos da radiação , Extratos Vegetais/química , Prunus/química
19.
Chem Biodivers ; 8(3): 532-9, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21404436

RESUMO

Drimys granadensis L.f., a native plant from Colombia, has been included in the Vademecum de Plantas Medicinales de Colombia by the Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, due to its widespread use in the folk medicine for the treatment of gastrointestinal ailments. The chemical composition of the essential oil of Drimys granadensis obtained by hydrodistillation of the leaves was analyzed by GC and GC/MS analyses. A total of 85 components were identified, with the major compounds germacrene D (1, 14.7%), sclarene (9.5%), a-cadinol (7.3%), longiborneol acetate (2, 6.3%), drimenol (4.2%), (Z)-ß-ocimene (3, 4.2%), a-pinene (4, 3.2%), and ß-elemene (5, 2.7%). The essential oil was also tested against eight bacteria using the Kirby-Bauer disk-diffusion method. Most of the Gram-positive bacteria tested were susceptible to the D. granadensis essential oil, while the Gram-negative bacteria tested were not.


Assuntos
Antibacterianos/farmacologia , Bactérias Gram-Positivas/efeitos dos fármacos , Óleos Voláteis/farmacologia , Folhas de Planta/química , Winteraceae/química , Antibacterianos/química , Antibacterianos/isolamento & purificação , Colômbia , Testes de Sensibilidade Microbiana , Estrutura Molecular , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Folhas de Planta/crescimento & desenvolvimento , Estereoisomerismo , Relação Estrutura-Atividade , Winteraceae/crescimento & desenvolvimento
20.
Mol Ecol ; 19(14): 2949-63, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20609080

RESUMO

Few chloroplast-based genetic studies have been undertaken for plants of mesic temperate forests in the southern hemisphere and fossil-based models have provided evidence of vegetation history only at the broadest scales in this region. This study investigates the chloroplast DNA phylogeography of Tasmannia lanceolata (Winteraceae), a fleshy-fruited, bird-dispersed shrub that is widespread in the mountains of southeastern Australia and Tasmania. Thirty haplotypes were identified after sequencing 3206 bp of chloroplast DNA in each of 244 individuals collected across the species' range. These haplotypes showed unexpectedly strong phylogeographic structuring, including a phylogeographic break within a continuous part of the species' range, with the distribution of four major clades mostly not overlapping, and geographic structuring of haplotypes within these clades. This strong geographic patterning of chloroplast DNA provided evidence for the survival of T. lanceolata in multiple putative wet forest refugia as well as evidence for additional wet forest species refugia in southeastern Australia. In western Tasmania lower haplotype diversity below the LGM tree line compared to above the LGM tree line suggests that glacial refugia at high altitudes may have been important for T. lanceolata. The level of geographic structuring in T. lanceolata is similar to gravity dispersed southern hemisphere plants such as Nothofagus and Eucalyptus. Behavioural traits of the birds transporting seed may have had a strong bearing on the limited transport of T. lanceolata seed, although factors limiting establishment, possibly including selection, may also have been important.


Assuntos
Evolução Molecular , Filogenia , Winteraceae/genética , Animais , Austrália , Aves , DNA de Cloroplastos/genética , DNA de Plantas/genética , Geografia , Haplótipos , Análise de Sequência de DNA , Tasmânia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...