40 research outputs found

    Platelet Antiaggregating Activity and Chemical Constituents of Salvia x Jamensis J. Compton

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    A phytochemical study has been carried out on the surface exudate of Salvia x jamensis, which showed a significant platelet antiaggregating activity. The known compounds isopimaric acid (2), 14-α-hydroxy-isopimaric acid (3), 3β-hydroxy-isopimaric acid (4), 7,8β-dihydrosalviacoccin (5), betulinic acid (6), and ursolic acid (7) were isolated together with the new diterpene 1. The structure of 1 was determined as 15,16-epoxy-cleroda-3-en-7α,10β-dihydroxy-12,17;19,18-diolide on the basis of spectroscopic data analysis. Among all tested compounds, 2 showed a significant concentration-dependent antiaggregating activity when ADP (3 μM) was used as agonist on rat platelets. Conversely, 1 increased ADP–induced platelet aggregation

    Phytotoxic activity of Salvia x jamensis.

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    A study has been carried out on the surface exudate of Salvia x jamensis, which showed a significant phytotoxic activity against Papaver rhoeas L. and Avena sativa L.. Bioguided separation of the exudate yielded active fractions from which 3β-hydroxy-isopimaric acid (1), hautriwaic acid (2), betulinic acid (3), 7,8β-dihydrosalviacoccin (4), isopimaric acid (5), 14α-hydroxy-isopimaric acid (7), 15,16-epoxy-7α,10β-dihydroxy-clerod-3,13(16),14-trien-17,12;18,19-diolide (8), cirsiliol (5,3′,4′-trihydroxy-6,7-dimethoxyflavone, 9) and two new neoclerodane diterpenes (6 and 10) were isolated. The structures of 6 and 10 were identified as 15,16-epoxy-10β-hydroxy-clerod-3,13(16),14-trien-17,12;18,19-diolide and 15,16-epoxy-7α,10-dihydroxy-clerod-2,13(16),14-trien-17,12;18,19-diolide respectively on the basis of spectroscopic data analysis. All compounds, but 7, 8 and 10, were active in inhibiting the germination of the tested species

    Constituents from Maytenus ilicifolia leaves and bioguided fractionation for gastroprotective activity

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    Maytenus ilicifolia Mart. ex Reissek is traditionally used in Brazil for treatment of gastric ulcers. Here we report the phytochemical investigation of an ethanol extract of M. ilicifolia leaves (EEMIL) aiming at the isolation of constituents which were used as chemical markers to monitor an activity-guided fractionation of a lyophilized aqueous extract of M. ilicifolia leaves (LAEMIL). From EEMIL, four flavonoids were isolated, namely the tri-flavonoid glycosides mauritianin (1), trifolin, (2) hyperin (4), and epi-catechin (5). Fractionation of LAEMIL led to 5 fractions which afforded the tetra-glycoside kaempferol derivative (3), and galactitol (6). LAEMIL and its fractions were evaluated in rats for their effects on gastric secretion volume and pH. HPLC (High Performance Liquid Chromatography) analysis revealed that only fractions containing the tri- and tetra-flavonoid glycosides 1 and 3 caused significant increase of gastric volume and pH, thus indicating that these glycosides play an important role on the gastroprotective effect of M.ilicifolia leaves.Maytenus ilicifolia Mart. ex Reissek é tradicionalmente usada no Brasil para o tratamento de úlcera gástrica. O presente trabalho relata a investigação fitoquímica de um extrato etanólico de folhas de M. ilicifolia (EEMIL) visando o isolamento de constituintes que foram usados como marcadores químicos para monitorar o fracionamento de um extrato aquoso liofilizado de folhas de M. ilicifolia (LAEMIL). De EEMIL, quatro flavonóides foram isolados, compreendendo o triglicosídeo flavônico mauritianina (1), trifolina (2), hyperina (4), e epi-catequina (5). O fracionamento de LAEMIL levou a 5 frações, fornecendo um derivado tetraglicosilado de canferol (3), além do galactitol (6). LAEMIL e suas frações foram avaliadas quanto aos efeitos sobre o volume e pH da secreção gástrica em ratos. Análise por CLAE (Cromatografia Líquida de Alta Eficiência) revelou que somente frações contendo o tri- e tetra-glicosídeos flavônicos 1 e 3 causaram aumento significativo de volume gástrico e pH, indicando que esses glicosídeos têm importante papel sob o efeito gastroprotetor de folhas de M. ilicifolia

    Arjunglucoside II from Quercus ilex L. and Quercus suber L. 16. Contents of Cupuliferae

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    Chemical study of Anchusa officinalis (Boraginaceae) using spectroscopic method

    Revised structures of triterpene saponins from Anchusa officinalis L

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    The paper describes the revision of the structures of triterpene saponins from Anchusa officinalis using NMR, UV, IR, MS

    Oxidative stability of virgin olive oil enriched with carnosic acid

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    The aim of this study was to evaluate the effect of the addition of carnosic acid on the oxidative stability of virgin olive oil. Two different amounts of carnosic acid (0.01 and 0.1 g/100 g oil) and two different temperatures (accelerated aging temperature, 60 °C; deep frying temperature, 180 °C) were considered. The influence of carnosic acid and heating time on the stability of the oils was studied by experimental design. The results obtained at 60 °C showed a dose dependent inhibition in the formation of primary and secondary oxidation products and a dose dependent enhancement of radical scavenging activity, which was only less significantly influenced by heating time. On the contrary, at 180 °C no protective effect against lipid oxidation was observed and the radical scavenging activity was practically zeroed by heating, probably as a consequence of a fast decomposition of carnosic acid

    Flavonoids and triterpenoids from Salvia blepharophylla

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    The phytochemical study of Salvia Salvia blepharophylla (Labiatae) afforded triterpenese and Flavonoid

    Minor polyphenols from Quercus rubra L. Part 21: Constituents of Fagaceae (Cupuliferae)

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    Phytochemical studies 0f Fabaceae constituents afforded polyphenols, whose structural characterization was obtained using spectroscopic data.
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