Constituintes químicos de Gustavia augusta L. (Lecythidaceae)

Gustavia augusta is used in the folk medicine against leishmaniosis and showed anti-inflammatory action. The phytochemical studies of the plant stem bark have led to the isolation of (22E)-stigmasta-7,22-dien-3beta-ol, 24alpha(S)-ethyl-5alpha-colesta-7,trans-22-dien-3-one, D-friedoolean-14-en-3beta-ol, D-friedoolean-14-en-3-one and D-friedoolean-14-en-3alpha-ol along with stigmasterol, alpha-amyrin, beta-amyrin, lupeol, 3alpha-hidroxi-lupeol and betulinic acid. The structures of these compounds were identified by IR, GC/MS, ¹H and 13C NMR spectral analysis and comparison with literature data.

Efeito da substituição por átomos de flúor no equilíbrio conformacional de chalcona

Chalcone (1) and its fluorinated derivatives 2-4, as well as their cyclic analogues 5-10, were synthesized through an aldol condensation reaction between the corresponding ketone and aldehyde. These compounds were characterized by IR, EIMS and ¹H and 13C NMR spectral data. Modern NMR techniques allowed us to conclude that the compounds obtained show E configuration. These techniques were also employed to investigate the equilibrium involving the s-cis and s-trans conformations of 1-4, with this equilibrium being dependent on the fluorine substitution on both aromatic rings, A or B. IR studies indicated that the yield of the s-cis conformation in the fluorinated derivatives is 57.4±1.4; 88.1±0.4 and 66.4±0.7%, for 2, 3 and 4, respectively, based on previous ¹H NMR calculations for chalcone. Theoretical calculations, using the MMX method, were employed to justify the variation of chemical shifts for the fluorinated derivatives and cyclic analogues. These chemical shifts are consequence of the anisotropic effect showed by the carbonyl group on these compounds.

Diterpenóides com esqueleto cleistantano de Vellozia aff. carunculares martius ex seubert (Velloziaceae)

From the hexane extract of leaves, stem and roots, of Vellozia aff. carunculares, fourteen cleistanthane diterpenoids were detected by HRGC-MS, through the analysis of their fragmentation patterns. Comparison of their MS spectra with those of authentic standards previously isolated from other species of the family Velloziaceae allowed the identification, with a high degree of confidence, of eigth known cleistanthane diterpenoids. Of these, four were isolated and identified from their MS, IR and ¹H and 13C NMR spectra, as the known cleistantha-8,11,13-trien-7-one, cleistantha-8,11,13-trien-3,7-dione, cleistantha-1,8,11,13-tetraen-3,7-dione and the first reported 6-alpha-hydroxy-cleistantha-8,11,13-trien-7-one. The triterpenoid beta-amyrin was also isolated.

Constituintes químicos isolados de simira glaziovii (K. schum) steyerm. e a atribuição dos deslocamentos químicos dos átomos de carbono e hidrogênio do alcalóide ofiorina e seus derivados

Chromatographic fractionation of bark extracts from Simira glaziovii (Rubiaceae) afforded the steroids beta-sitostenone, stigmastenone, beta-sitosterol and stigmasterol, methyl trans-4-hidroxy-3-methoxycinamate (1), the alkaloids harmane (2) and the new stereoisomer of ophiorine B (3). The structures were established by ¹H and 13C NMR, including 2D techniques and mass spectral analysis, of the natural products and pentaacetyllyalosidic acid (4a) and beta-carboline monoterpene tetraacetylglucoside (5, 1,22-lactamlyaloside) derivatives obtained by chemical transformations.

Estudo fitoquímico e avaliação da atividade moluscicida da Kielmeyera variabilis Mart (Clusiaceae)

Methanol extract obtained from Kielmeyera variabilis stems showed significant molluscicidal activity against Biomphalaria glabrata. The phytochemical studies of the plants stem to the isolation of three xanthones (assiguxanthone-B, kielcorin and 1,3,5,6-tetrahtydroxy-2-prenylxanthone) and a organic acid (2,5-dihydroxy benzoic acid). The structures of these compounds were identified by IR, MS, ¹H and 13C NMR spectral analysis and comparison with literature data.

Flavonóides e triterpenos de Baccharis pseudotenuifolia: bioatividade sobre Artemia salina

The phytochemical investigation of the chloroformic and methanolic extracts of the Baccharis pseudotenuifolia led to the isolation of triterpenes, steroids and flavonoids. From chloroformic extract were isolated oleanolic acid and alpha-spinasterol while from methanolic extract were isolated the flavonoids: hispidulin, naringenin, 3'-methoxy-luteolin, apigenin, kaempferol, eriodyctiol, aromadendrin, quercetin, 3'-methoxy-quercetin, quercetin-3-O-rhamnoside and quercetin-3-O-glucoside. The structure of these compounds were identified by IR, CG/MS, ¹H and 13C NMR spectral analysis and comparison with literature. In addition, the extracts were evaluated by means of Brine Shrimp Lethality test and the highier activity was observed in the chloroformic extract.

Novel santalane sesquiterpenoids from the stem bark of Duguetia glabriuscula - Annonaceae

Five novel santalane-type sesquiterpenes were isolated from the stem bark of Duguetia glabriuscula - Annonaceae. Their structures have been established on the basis of spectral data and chemical evidences (¹H and 13C NMR, HMQC, HMBC) as (+)-alpha-santal-10-en-9-ol (1), (+)-alpha-santalan-10,11-epoxy-9-ol (2), alpha-santal-11-en-9,10-diol (3), (+)-alpha-santalan-9,10,11-triol (4), and (+)-alpha-santalan-9,11-epoxy-10-ol (5). Polycarpol, a triterpenoid, was also obtained.

Determinação de compostos de massa molecular alta em folhas de plantas da Amazônia

The fractIons of dichloromethane extracts of leaves from andiroba (Carapa guianensis - Meliaceae), caapi (Banisteriopsis caapi - Malpighiaceae), cocoa (Theobroma cacao - Sterculiaceae), Brazil nut (Bertholletia excelsa - Lecytidaceae), cupuaçu (Theobroma grandiflorum - Sterculiaceae), marupá (Simaruba amara - Simaroubaceae) and rubber tree (Hevea brasiliensis - Euphorbiaceae), were analyzed by HT-HRGC and HT-HRGC-MS. Esters of homologous series of fatty acids and long chain alcohols, phytol, amyrines and tocopherols were characterized. The characterization of the compounds was based mainly in mass spectra data and in addition by usual spectrometric data (¹H and 13C NMR, IR).

Lignanas de Strychnos guianensis (Aublet) Mart.

The present communication reports the isolation and identification of three lignans from metanolic root extracts of Strychnos guianensis (Aublet) Mart.: olivil (1), cycloolivil (2) and the unknown derivative cycloolivil carbonate (3). From hexane extracts was identified a long chain fatty acid mixture and the triterpene lupeol. The analyses were based on chromatographic and spectroscopy techniques (IR, MS, GC/MS, ¹H-NMR and 13C-NMR, 1D (BB, DEPT 135) and 2D (¹H, ¹ H-COSY, ¹H, 13C-COSY, ¹H, 13C-COSY-LR, HMQC, HMBC and NOESY) and comparison with literature data.

Triterpenóides tipo cicloartano de própolis de Teresina - PI

The chemical study of the propolis produced in Teresina city, state of Piaui, resulted in the identification of six cycloartane triterpenoids: isomangiferolic acid, 24-methylenecycloartane-3beta,26-diol, mangiferolic acid, mangiferonic acid, ambonic acid and ambolic acid. The substances were characterized by one and two-dimensional ¹H and 13C NMR analysis.

Triterpenóides pentacíclicos das folhas de Terminalia brasiliensis

Eleven oleanane, ursane and lupane-type triterpenes were isolated from the leaves of Terminalia brasiliensis Camb, daturadiol (3b,6beta-dihydroxy-olean-12-ene), 3beta-hydroxy-30-norlupan-20-one, lupenone, beta-amyrenone, alpha-amyrenone, lupeol, beta-amyrin, alpha-amyrin, betulin, erythrodiol and uvaol, in addition to squalene, sitosterol and alpha-tocopherol. The structures of these compounds were identified by ¹H and 13C NMR spectral analysis and comparison with literature data.

Constituintes químicos de Bombacopsis glabra (bombacaceae)

The chemical study of the barks of the stem and roots of Bombacopsis glabra (Bombacaceae) led to the isolation and identification of 5-hydroxy-3,7,4'-trimethoxyflavone (1), 5-hydroxy-3,6,7,4'-tetramethoxyflavone (2), the naphtoquinone isohemigossypolone (3), the ester triacontil p-coumarate (4) besides lupeol and a mixture of beta-sitosterol and stigmasterol. Their structures were elucidated by spectroscopic analysis, including IR, ¹H and 13C NMR and MS. All these compounds, except 3, were isolated for the first time in the family.

Síntese de aliloxi-orto-iodobenzamida derivada de d-glicose e reação de ciclização radicalar mediada por hidreto de tri-n-butilestanho

Methyl 6-O-allyl-2,3-di-O-benzyl-4-deoxy-4-(2 -iodobenzoylamine)-alpha-D-glucopyranoside was synthesized in nine conventional steps from methyl alpha-D-glucopyranoside. Its Bu3SnH-mediated aryl radical cyclization provided a benzomacrolactam, resulting from 11-endo aryl radical cyclization and the reduced uncyclized product methyl 6-O-allyl-4-benzoylamine-2,3-di-O-benzyl-4-deoxy- alpha-D-glucopyranoside. The structures of the three new products were supported by ¹H and 13C NMR spectroscopy and DEPT, COSY and HMQC experiments.

Constituintes químicos da casca do caule de Amburana cearensis A.C. Smith

The phytochemical analysis of the ethanol extract trunk bark of Amburana cearensis allowed the isolation and identification of twelve constituents: coumarin, sucrose, two phenol acids (vanillic acid and protocatechuic acid), five flavonoids (afrormosin, isokaempferide, kaempferol, quercetin and 4'-methoxy-fisetin), a phenol glucoside (amburoside A) and a mixture of glucosilated b-sitosterol and stigmasterol. Their structures were elucidated by spectroscopic methods such as IR, MS, ¹H and 13C NMR, including uni and bidimensional techniques, in addition to comparison with literature data.

Metabólitos secundários de Esenbeckia almawillia Kaastra (Rutaceae)

The phytochemical investigation of the roots of E. almawillia is reported for the first time. Chromatographic fractionation of the methanol extract allowed the isolation of the alkaloids 3,3-diisopentenyl-N-methyl-2,4-quinoldione (1), maculine (2) and 3'-methoxygraveoline (3), (E)-N-isobutyl-3-methoxy-4,5-methylenedioxicinnamoyl amide (4), the flavones gardenine B (5) and nevadensin (6), and the sesquiterpene intermediol (7). Structure elucidation was based on the analysis of their spectrometric data (uni- and bidimensional ¹H and 13C NMR, MS and IR) and comparison with literature data. Compounds 3-7 are being reported as constituents of Esenbeckia species for the first time.