7,292 research outputs found
Chemical and biological investigations of Delonix regia (Bojer ex Hook.) Raf.
U radu je opisana izolacija pet sastojaka petroleterske i diklormetanske frakcije metanolnog ekstrakta kore biljke Delonix regia: lupeol (1), epilupeol (2), β-sitosterol (3), stigmasterol (4) i p-metoksibenzaldehid (5). Nadalje, testirano je antimikrobno djelovanje različitih ekstrakata difuzijskom metodom na disku (15 μg mm2). Zone inhibicije za sastojke topljive u petroleteru, tetraklormetanu i diklormetanu bile su 914 mm, 1113 mm, odnosno 920 mm, dok je zona inhibicije standarda kanamicina bila 2025 mm. U biološkom pokusu smrtnosti morskih kozica najveću toksičnost pokazali su spojevi topljivi u tetraklormetanu (LC50 = 0,83 μg mL1), dok je topljivost sastojaka topljivih u petroleteru i diklormetanu bila LC50 14,94, odnosno 3,29 μg mL1, a standarda vinkristin sulfata 0,812 μg mL1. Ovo je prvo izvješće o izolaciji sastojaka, antimikrobnom djelovanju i citotoksičnosti biljke D. regia.In this study five compounds, lupeol (1), epilupeol (2), β-sitosterol (3), stigmasterol (4) and p-methoxybenzaldehyde (5) were isolated from the petroleum ether and dichloromethane fractions of a methanolic extract of the stem bark of Delonix regia. Antimicrobial screening of the different extracts (15 μg mm2) was conducted by disc diffusion method. The zones of inhibition demonstrated by the petroleum ether, carbon tetrachloride and dichloromethane fractions ranged from 914 mm, 1113 mm and 920 mm, respectively, compared to kanamycin standard with the zone of inhibition of 2025 mm. In brine shrimp lethality bioassay, the carbon tetrachloride soluble materials demonstrated the highest toxicity with LC50 of 0.83 μg mL1, while petroleum ether and dichloromethane soluble partitionates of the methanolic extract revealed LC50 of 14.94 and 3.29 μg mL1, respectively, in comparison with standard vincristine sulphate with LC50 of 0.812 μg mL1. This is the first report on compounds separation from D. regia, their antimicrobial activity and cytotoxicity
Fruit characteristics and cuticle triterpenes as related to postharvest quality of highbush blueberries
Chilean fresh blueberries take 20-50 days to arrive by boat to the Northern hemisphere, softening and dehydration being the main defects upon arrival. The effect of maturity at harvest (75% blue, 100% blue, and overripe) on cuticular triterpene content, and the possible associated impacts on firmness and weight loss after cold storage were explored for 'Duke' and 'Brigitta' fruit, both non-bagged or bagged in macroperforated low-density polyethylene bags. Softening and weight loss varied with cultivar and maturity stage: 'Duke' fruit softened faster and were more prone to dehydration than 'Brigitta' samples, whereas overripe fruit were less firm after storage. This is the first report characterizing the triterpenoid fraction in cuticles of fresh blueberries, which may play a role in their postharvest behavior. Weight loss and softening rates were highly correlated to ursolic acid contents at harvest; further research will be required for a better understanding of these relationships.Fruit samples were provided by AMS Family, Maule Region, Chile. We thank Irene Manríquez, Instituto de Química de Recursos Naturales, Universidad de Talca, for her skillful technical work. In Chile, this work was supported by the National Commission for Scientific and Technological Research CONICYT (FONDECYT 11130539) and PCHA/Doctorado Nacional/2013-63130042, the research programs “Adaptation of Agriculture to Climate Change (A2C2)”, “PIEI-QUIM-BIO”, “Fondo Proyectos de Investigación” and “Núcleo Científico Multidisciplinario”, Universidad de Talca. In Spain this work was partially supported by “Fundación Carolina” and “Programa de Doctorado en Ciencia y Tecnología Agraria y Alimentaria”, Universitat de Lleida
Cassane diterpenoids from lonchocarpus laxiflorus
This article examines cassane diterpenoids from lonchocarpus laxiflorus
Comparison of phenolic and volatile profiles of edible and toxic forms of Detarium senegalense J. F. GMEL
In Senegal, Detarium senegalense J.F. Gmel. (ditax in Wolof) is one of the most important important forest fruit species. However, exploitation of the edible fruit is based on local people's knowledge. Only trees whose fruits are consumed by animals are exploited. To identify them, a chemical comparison of edible and toxic forms was done in order to highlight differences between both forms. Dichloromethane leaf extracts from toxic and edible trees were analyzed by gas chromatography. Phenolic profile and volatile compounds from fruits extracts were studied respectively by High Performance Liquid Chromatography-mass spectrometry (HPLC-MS) and Gas Chromatography Mass Spectrometry (GC-MS). Cytotoxicity effect of fruits extracts was evaluated on murine macrophage cells J774 A1. GC-analysis of dichloromethane leaf extracts revealed the presence of lupenone and lupeol only in toxic extracts. 6'-O-galloyl-epiheterodendrin and isovaleronitrile were detected in toxic pulp. However, no cytotoxic effect was found in our conditions. This study has given the opportunity to identify within the same species, compounds which could differentiate both edible and toxic forms. Nevertheless further studies are needed to better understand which compounds are responsible for toxicity in the toxic form. (Résumé d'auteur
Olive oil
Analyses of phytosterol classes of olive and hazelnut oils collected from different countries by TLC, GC and GC-MS revealed considerable quantitative differences. The composition of 4-desmethyl- and 4-monomethylsterols was similar in both oils, but 4,4'-dimethylsterols composition differed. Lupeol and an unknown (lupane skeleton) compound were exclusively present in hazelnut oil 4,4´-dimethylsterols and could be used as markers to detect virgin olive oil adulteration with hazelnut oil at levels below 4%. Conventional TLC to separate phytosterol classes has a low recovery rate and is time-consuming. A new SPE method to separate phytosterol classes was developed with stepwise elution by increasing the polarity of the n-hexane:diethyl ether solvent mixture. Comparison of the results obtained for hazelnut and virgin olive oils with those of TLC revealed that the SPE method was faster and gave higher sterol recovery rates. Free and esterified forms of sterols provide detailed information on the identity and quality of vegetable oils, and therefore 4,4´-dimethylsterols were investigated in hazelnut oil and virgin olive oil. A sample of solvent-extracted hazelnut oil was refined to monitor the effects of processing on 4,4´-dimethylsterol levels and on specific marker compounds. Of the refining processes tested, only neutralisation and bleaching considerably reduced 4,4´-dimethylsterols. In fully-refined hazelnut oil, losses of marker compounds in free form were higher than losses in their esterified form. GC-MS analysis showed that adulteration of olive oil with fully-refined hazelnut oil could be detected at levels of 2% by tracing lupeol in total/esterified forms of 4,4´-dimethylsterols. Olive oil has many applications in the food industry, e.g. blended with oils such as palm stearin to produce margarine or shortening by chemical interesterification. Investigation on lipid and minor lipid components of an olive oil-palm stearin blend during chemical interesterification showed that sterols were esterified with fatty acids at a higher level at 120 °C (7%) than at 90 °C (4%). Despite heat treatment and several steps to produce an interesterified product, there were minor losses in phytosterol and tocopherol contents and no significant increases in phytosterol oxidation
Current status of herbal and their future perspectives
Traditional medicine is the synthesis of therapeutic experience of generations of practicing physicians of indigenous systems of medicine. Throughout the history of mankind, many infectious diseases have been treated with herbals. The traditional medicine is increasingly solicited through the tradipractitioners and herbalists in the treatment of infectious diseases. Among the remedies used, plant drugs constitute an important part. A number of scientific investigations have highlighted the importance and the contribution of many plant families i.e. Asteraceae, Liliaceae, Apocynaceae, Solanaceae, Caesalpinaceae, Rutaceae, Piperaceae, Sapotaceae used as medicinal plants. Medicinal plants play a vital role for the development of new drugs (export and import diverse parts or bioactive compounds in the current market). The bioactive extract should be standardized on the basis of active compound. The bioactive extract should undergo limited safety studies
Functional analysis and overexpression of a Glycogen Synthase Kinase-3β gene in Lotus japonicus during plant interaction with rhizobia
Fermentation and purification strategies for the production of betulinic acid and its lupane-type precursors in Saccharomyces cerevisiae
Microbial production of plant derived, biologically active compounds has the potential to provide economic and ecologic alternatives to existing low productive, plant-based processes. Current production of the pharmacologically active cyclic triterpenoid betulinic acid is realized by extraction from the bark of plane tree or birch. Here, we reengineered the reported betulinic acid pathway into Saccharomyces cerevisiae and used this novel strain to develop efficient fermentation and product purification methods. Fed-batch cultivations with ethanol excess, using either an ethanol-pulse feed or controlling a constant ethanol concentration in the fermentation medium, significantly enhanced production of betulinic acid and its triterpenoid precursors. The beneficial effect of excess ethanol was further exploited in nitrogen-limited resting cell fermentations, yielding betulinic acid concentrations of 182mg/L, and total triterpenoid concentrations of 854mg/L, the highest concentrations reported so far. Purification of lupane-type triterpenoids with high selectivity and yield was achieved by solid-liquid extraction without prior cell disruption using polar aprotic solvents such as acetone or ethyl acetate and subsequent precipitation with strong acids. This study highlights the potential of microbial production of plant derived triterpenoids in S. cerevisiae by combining metabolic and process engineering
Phytochemical Characterization of Xerospermum Noronhianum
Xerospermum noronhianum, locally known as gigi buntal (globe-fish’s teeth) or
rambutan pachat (leech’s rambutan) is a species belonging to the Sapindaceae family.
The Sapindaceae are generally well known as a prolific source of plant saponins.
However, to date, there has been no systematic phytochemical and biological evaluation
on this particular species. In the present study, several known compounds have been
successfully isolated from various plant parts and solvent fractions of Xerospermum
noronhianum. Three new triterpenoid saponins have been purified from the ethyl acetate
and aqueous fractions of both stem and leaf of the plant. Through the use of high field
NMR and mass spectroscopy, these saponins have been identified to be those of the
oleanane-type, i.e 3-O-{α-L-rhamnopyranosyl(1→2)-β-D-fucopyranosyl}-28-O-{[α-Lrhamnopyranosyl(
1→2)][α-L-rhamnopyranosyl(1→6)]}-β-D-glucopyranosyl oleanolic
acid, 3-O-{α-L-rhamnopyranosyl(1→3)-β-D-fucopyranosyl}-28-O-{α-Lrhamnopyranosyl(
1→4)}-β-D-glucopyranosyl oleanolic acid and 3-O-{α-Lrhamnopyranosyl(
1→2)-[3’,4’-diacetoxy-β-D-fucopyranosyl]}-28-O-{α-L rhamnopyranosyl(1→2)}-β-D-glucopyranosyl oleanolic acid. Several known compounds
have also been isolated and identified as the free triterpenes namely lupeol, oleanolic
acid, friedelin, 3β-hydroxy-29-nor-20-lupenone, 3β-hydroxy-lup-20(29)en-30-al,
mixture of 3β-hydroxyolean-12-en-11-one and 3β-hydroxyurs-12-en-11-one; the
flavonoid glycosides kampferol-3-O-rhamnoside, quercetin-3-O-rhamnoside; the
benzoic acid derivatives 3,5-dihydroxy-4-methoxybenzoic acid, 3,4-dihydroxybenzoic
acid, 3,4,5-trihydroxybenzoic acid; as well as scopoletin, lupeol palmitate, and palmitic
acid, mixture of β-sitosterol and stigmasterol and mixture of their glycosides. Oxidation
of the major compound, lupeol, successfully yielded lupenone as the product.
The crude extracts and isolated pure compounds were also further evaluated for their
anti-cholinesterase activity, against two enzymes; acetylcholinesterase and
butyrylcholinesterase, using thin layer chromatography bioautographic method. The
inhibition activities of the test samples were expressed as pMIQ values, which represents
the negative logarithm of the minimal inhibitory quantity (in moles) that produced the
spot with the least observable whiteness. Generally, the crude extracts of stem, leaf and
bark parts, all showed inhibition in the preliminary screening by giving white observable
inhibition spots against a yellow-coloured background. The enzyme inhibiting
constituents were, in part, found to be due to the triterpenoidal saponins, the free
triterpenes as well as the sterol and its glycosides. However, the tested compounds were
considered to be weakly active due to their low pMIQ values. Compounds with pMIQ
values ≥ 10.5 is considered to be bioactive. All of the tested compounds in this study
gave pMIQ value in the range of 1.7 to 3.7
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