27 research outputs found

    Diterpene and other constituents from Stemodia maritima (Scrophulariaceae)

    Full text link
    A new diterpene, (5S*,8S*,9R*,10S*)-11β,12β-epoxy-9α-hydroxy-19(4→3) abeo-abieta-3,13-diene-19,18-olide, together with the known compounds stemodin, D-mannitol, betulinic acid, a mixture of 3β-O-β-D-glucopyranosyl-β-sitosterol and 3β-O-β-D-glucopyranosylstigmasterol and 5,7,4'-trihydroxy-3,8,3'-trimethoxyflavone were isolated from the leaves and stems of Stemodia maritima. Structural elucidation of all compounds was based on interpretation of spectral data, mainly NMR (1D and 2D) and MS, including comparison with values described in the literature

    Fitoquímica e quimiossistemática de Conchocarpus marginatus e C. inopinatus (Rutaceae)

    Full text link
    Phytochemical studies of the leaves and stem have led to the identification of the known acridone alkaloids arborinine, methyl-arborinine, 1-hydroxy-3-methoxy-N-methyl acridone, xanthoxoline, 1,2,3,5-tetramethoxy-N-methylacridone, toddaliopsin C and the new seco acridone alkaloid inopinatin. The known quinoline alkaloids 2-phenyl-1-methyl-quinolin-4(1H)-one, 2-phenyl-1-methyl-7-methoxy-quinolin-4(1H)-one, dictamnine, and the coumarins scopoletin and marmesin were also isolated. The isolated compounds and the distribution of secondary metabolites, which are systematically important, obtained from literature, clearly confirmed that some species formerly described in the genera Angostura and Galipea in fact shall belong to the genus Conchocarpus

    Fatty acids and terpenoids from Trigonia fasciculata

    No full text
    The fatty portion of the hexane extract from roots of Trigonia fasciculata has been determined by GC/MS analysis of the methyl ester mixture. Seventeen fatty acids were identified and oleic acid (38.8%) was the major component. The GC/MS analysis of the less polar fraction of the non-saponifiable part of the root hexane extract allowed the identification of fifteen sesquiterpenes and alpha-santalene (28.4%) was the major component. Chromatography over silica gel of the more polar fraction allowed the isolation of two known compounds: betulinic acid and friedelin, and a novel diterpene 7-(2-hydroxy-acetyl)-10-hydroxy-tetradecahydro-1-methylene-4b,7,10a-trimethyl -phenantrene (6alpha-hydroxy-15-oxo-allodevadarool), all unknown for the species. Structure determination was accomplished by chemical derivatization, comparison to literature data and spectral analysis, including 2D NMR (COSY, HETCOR, COLOC) and X-ray crystallography

    Thiocarbamates from Moringa oleifera Seeds Bioactive against Virulent and Multidrug-Resistant Vibrio Species

    No full text
    Prospect of antibacterial agents may provide an alternative therapy for diseases caused by multidrug-resistant bacteria. This study aimed to evaluate the in vitro bioactivity of Moringa oleifera seed extracts against 100 vibrios isolated from the marine shrimp Litopenaeus vannamei. Ethanol extracts at low (MOS-E) and hot (MOS-ES) temperature are shown to be bioactive against 92% and 90% of the strains, respectively. The most efficient Minimum Inhibitory Concentration (MIC) levels of MOS-E and MOS-ES against a high percentage of strains were 32 µg mL−1. Bioguided screening of bioactive compounds showed that the ethyl acetate fraction from both extracts was the only one that showed antibacterial activity. Vibriocidal substances, niazirine and niazimicine, were isolated from the aforementioned fraction through chromatographic fractionation

    HS-SPME as an efficient tool for discriminating chemotypes of Lippia Alba(Mill.) N. E. Brown

    No full text
    Lippia alba (Mill.) N. E. Brown (Verbenaceae) is a medicinal plant for which several biological activities are reported, such as sedative, anxiolytic, anti-ulcer, antifungal, antimicrobial, antioxidant, antispasmodic, anti-nociceptive and anti-inflammatory. It is characterized by the production of essential oils which have been used to classify the plant in different chemotypes. In the Northeast region of Brazil, the presence of three chemotypes are reported: myrcene-citral (chemotype I), limonene-citral (chemotype II) and carvone-limonene (chemotype III). In this work, headspace-solid phase microextraction (HS-SPME) was used on the analysis of the volatile organic compounds (VOCs) of three chemotypes of L. alba from the Northeast region of Brazil, and compared to the essential oils of the plants extracted by hydrodistillation. Volatile compounds from each chemotype were more effectively differentiated when extracted by HS-SPME than by hydrodistillation

    Quantification of Barbatusin and 3 β

    No full text
    The concentration of diterpenes barbatusin (1) and 3β-hydroxy-3-deoxybarbatusin (2) in the extracts from leaves of Plectranthus grandis, P. barbatus, P. ornatus, and P. amboinicus was evaluated by HPLC-DAD analysis on a Luna C-18 column, using isocratic mixtures of water and acetonitrile as eluents. The regression equations were obtained with good linearity (r2 > 0.99) and limit of quantifications was higher than 0.1 µg/mL. The precision (lower than 3.5%, within day) and accuracy (higher than 81.7% and lower than 107.6%) of the methods were adequate. Barbatusin (1) was detected in P. grandis (15.432 ± 2.28 mg/g) and P. barbatus (5.198 ± 3.45 mg/g) extracts, while compound 2 was detected in P. grandis (4.068 ± 3.34 mg/g), P. barbatus (0.654 ± 5.86 mg/g), P. amboinicus (0.160 ± 7.25 mg/g), and P. ornatus (0.763 ± 5.10 mg/g). The evaluated validation parameters were satisfactorily achieved, and the developed methodology represents a suitable tool for application in the quantification of barbatusin (1) and 3β-hydroxy-3-deoxybarbatusin (2) in Plectranthus species

    HS-SPME AS AN EFFICIENT TOOL FOR DISCRIMINATING CHEMOTYPES OF Lippia alba (Mill.) N. E. Brown

    No full text
    Lippia alba (Mill.) N. E. Brown (Verbenaceae) is a medicinal plant for which several biological activities are reported, such as sedative, anxiolytic, anti-ulcer, antifungal, antimicrobial, antioxidant, antispasmodic, anti-nociceptive and anti-inflammatory. It is characterized by the production of essential oils which have been used to classify the plant in different chemotypes. In the Northeast region of Brazil, the presence of three chemotypes are reported: myrcene-citral (chemotype I), limonene-citral (chemotype II) and carvone-limonene (chemotype III). In this work, headspace-solid phase microextraction (HS-SPME) was used on the analysis of the volatile organic compounds (VOCs) of three chemotypes of L. alba from the Northeast region of Brazil, and compared to the essential oils of the plants extracted by hydrodistillation. Volatile compounds from each chemotype were more effectively differentiated when extracted by HS-SPME than by hydrodistillation
    corecore