Abietatrienes diterpenoids from Sagittaria montevidensis SSP Montevidensis

The antimicrobial properties of the hexane, hexane/EtOAc and methanol fractions of the fresh petioles of Sagittaria montevidensis ssp montevidensis (Alismataceae) were evaluated against fungi and Gram-negative and Gram-positive bacteria. A new abietatriene-type diterpenoid, 3β,7α-dihydroxi-abieta-8,11,13-triene and the known 3β-hydroxy-abieta-8,11,13-trien-7-one were isolated from the most active fraction tested and the structures of these compounds were elucidated by data including IR, EIMS, and 1D and 2D NMR spectra.

Estudo químico de uma amostra de própolis verde de Passa Quatro, Minas Gerais, Brasil

The phytochemical investigation of a sample of propolis from Passa Quatro-Minas Gerais State, Brazil, where nine constituents were isolated: a mixture of α- and β-amyrin, lupeol, a mixture of flavonols ramnocitrin and eupalitin, acacetin, 3-prenyl-4-hydroxycinnamic acid, 3,5-diprenyl-4-hydroxycinnamic acid the new compound, the (E)-3-[4-(3-phenylpropanoiloxy)]-3,5-diprenil-cinnamic acid. The structures of the isolated compounds were characterized by 1D- and 2D-NMR experiments, MS and IR spectrometry, and comparison with data described in the literature.

Bromopyrrole alkaloids from the caribbean sponge Agelas cerebrum

Bioguided fractionation of Agelas cerebrum crude extract resulted in isolation of four bromopyrrole and four bromopyrrole aminoimidazole alkaloids, identified as 5-bromopyrrole-2-carboxylic acid (1), 4-bromopyrrole-2-carboxylic acid (2), 3,4-bromopyrrole-2-carboxylic acid (3), 4,5-bromopyrrole-2-carboxylic acid (4), oroidin (5), bromoageliferin (6), dibromoageliferin (7) and dibromosceptrin (8) on the basis of spectroscopic data analyses (UV, IR, HRMS, 1D and 2D NMR) and comparison with literature data. This is the first report of compounds 2 and 3 in a marine sponge belonging to the Agelas genus and the first evidence of the presence of 1 from a natural source.

Constituintes químicos e atividade Leishmanicida de Gustavia elliptica (Lecythidaceae)

The phytochemical investigation of the stem bark and leaves of G. elliptica provided a mixture of the norisoprenoids blumenol B and 6-epiblumenol B along with the triterpenes friedelin, as the major constituent, friedelanol, ursa-9(11),12-dien-3-ol, a-amyrin, β-amyrin, morentenol, epifriedelanol, as well as the sesquiterpenes trans-caryophyllene, α-humulene, ethyl hydnocarpate and other fatty acid esters. The identification of the compounds was performed on basis of spectrometric methods such as GC-MS, IR, MS and 1D and 2D NMR. Stem bark extracts showed significant leishmanicidal activity against promastigote forms of Leishmania braziliensis, with the best results for the chloroform extract.

Flavonoides e sesquiterpenos de Croton pedicellatus Kunth

The chemical investigation of the ethanolic extract from leaves of Croton pedicellatus yielded the bis-nor-sesquiterpenes blumenol A and blumenol A glucoside, along with the flavonoids: tiliroside, 6"-O-p-coumaroyl-β-galactopyranosyl- kaempferol, 6"-O-p-coumaroyl-β-glucopyranosyl-3"-methoxy- kaempferol, kaempferol, 3-glucopyranosyl-quercetin and alpinumisoflavone, as well as 4-hydroxy-3,5-dimethoxybenzoic acid. The identification of all isolated compounds was performed by spectrometric methods, including HR-ESI-MS, 1D and 2D NMR experiments, and by comparison with previously-described physical and spectral data.

Terpenoides e cumarinas de Jatropha ribifolia (Pohl) Baill

Eight compounds, including terpenoids (jatrophone, hydroxyjatrophone, 6-hydroxycyperene, cabraleadiol monoacetyl, and cabraleadiol) and coumarins (fraxetin, fraxidin, and isofraxidin), were isolated from Jatropha ribifolia (Euphorbiaceae). Their structures were established by 1D and 2D NMR (COSY, HSQC, and HMBC) spectra, HRESIMS and comparison with published data.

Alcaloides isoquinolínicos e investigação das atividades antiplasmódica e antibacteriana de Guatteria citriodora (Annonaceae)

Phytochemical investigations of the stem bark, leaves and twigs of Guatteria citriodora resulted in the isolation of eight alkaloids: liriodenine, lysicamine, O-methylmoschatoline, 3-methoxyoxoputerine, palmatine, 3-methoxyguadiscidine, guattescidine and oxoputerine. The structures of the isolated substances were established by extensive spectroscopic techniques (1D and 2D NMR) and mass spectrometry (MS), as well as by comparison with data reported in the literature. The in vitro antimalarial activity of the alkaloidal fractions of the leaves and twigs against Plasmodium falciparum FCR3 showed significant results, with IC50 = 1.07 and 0.33 mg mL-1, respectively. The alkaloidal fraction of the leaves showed moderate activity against Enterococcus faecalis, with IC50 = 125.0 mg mL-1. Antiplasmodial and antibacterial activities are attributed to alkaloidal constituents.

Other compounds isolated from Simira glaziovii and the ¹H and 13C NMR chemical shift assignments of new 1-epi-castanopsol

A new triterpene, 1-epi-castanopsol, besides eleven known compounds: sitosterol, stigmasterol, campesterol, lupeol, lupenone, simirane B, syringaresinol, scopoletin, isofraxidin, 6,7,8-trimethoxycoumarin and harman, were isolated from the wood of Simira glaziovii. The structures of the known compounds were defined by 1D, 2D ¹H, 13C NMR spectra data analyses and comparison with literature data. The detailed spectral data analyses allowed the definition of the structure of the new 1-epi isomer of castanopsol and performance of ¹H and 13C NMR chemical shift assignments.

Optimization and practical implementation of ultrafast 2D NMR experiments

Ultrafast 2D NMR is a powerful methodology that allows recording of a 2D NMR spectrum in a fraction of second. However, due to the numerous non-conventional parameters involved in this methodology its implementation is no trivial task. Here, an optimized experimental protocol is carefully described to ensure efficient implementation of ultrafast NMR. The ultrafast spectra resulting from this implementation are presented based on the example of two widely used 2D NMR experiments, COSY and HSQC, obtained in 0.2 s and 41 s, respectively.

CONSTITUENTS OF ESSENTIAL OIL AND HYDROLATE OF LEAVES OF Campomanesia viatoris LANDRUM

The chemical composition of the essential oil and hydrolates of Campomanesia viatoris Landrum were investigated by gas chromatography/mass spectrometry (GC/MS) and a GC flame ionization detector (GC-FID). The major constituents were tasmanone (70.50, essential oil; 74.73%, hydrolate), flavesone (12.77, essential oil; 12.24%, hydrolate) and agglomerone (6.79, essential oil; 10.84%, hydrolate). Tasmonone was isolated and its structure was characterized by spectrometric analysis, specifically 1D and 2D nuclear magnetic resonance (NMR) and mass spectrometry (MS). These findings supports the quimiotaxonomic relationship with Campomanesia and Eucalyptus genera.

Animal manure phosphorus characterization by sequential chemical fractionation, release kinetics and 31P-NMR analysis

Phosphate release kinetics from manures are of global interest because sustainable plant nutrition with phosphate will be a major concern in the future. Although information on the bioavailability and chemical composition of P present in manure used as fertilizer are important to understand its dynamics in the soil, such studies are still scarce. Therefore, P extraction was evaluated in this study by sequential chemical fractionation, desorption with anion-cation exchange resin and 31P nuclear magnetic resonance (31P-NMR) spectroscopy to assess the P forms in three different dry manure types (i.e. poultry, cattle and swine manure). All three methods showed that the P forms in poultry, cattle and swine dry manures are mostly inorganic and highly bioavailable. The estimated P pools showed that organic and recalcitrant P forms were negligible and highly dependent on the Ca:P ratio in manures. The results obtained here showed that the extraction of P with these three different methods allows a better understanding and complete characterization of the P pools present in the manures.

Constituintes químicos de Ottonia corcovadensis Miq. da floresta Amazônica: atribuição dos deslocamentos químicos dos átomos de hidrogênio e carbono

In an ethanolic extract of leaves of Ottonia corcovadensis (Piperaceae) were identified sixteen terpenoids of essential oil and the three flavonoids 3',4',5,5',7-pentamethoxyflavone (1), 3',4',5,7-tetramethoxyflavone (2) and 5-hydroxy-3',4',5',7-tetramethoxyflavone (3) and cafeic acid (4). Two amides (5 and 6) were isolated from an ethanolic extract of the roots. The structures were established by spectral analysis, meanly NMR (1D and 2D) and mass spectra. Extensive NMR analysis was also used to complete ¹H and 13C chemical shift assignments of the flavonoids and amides. The components of the essential oil were identified by computer library search, retention indices and visual interpretation of mass spectra.

Determinação por RMN das configurações relativas e conformações de alcalóides oxindólicos isolados de Uncaria guianensis

Phytochemical studies with leaves of Uncaria guianensis resulted in the isolation of the oxindole alkaloids isomitraphylline (1), 3-isoajmalicine (2) mitraphylline (3), and isomitraphylinic acid (4). Structural assignments of these alkaloids, including relative configurations and conformations, were performed through spectral data and physical properties. 1D and 2D homonuclear and heteronuclear NMR spectroscopy was a valuable tool for the establishment of the relative stereochemistry of those compounds.

Flavonoides e outras substâncias de Lippia sidoides e suas atividades antioxidantes

The chemical investigation of the ethanol extracts of stems, roots and leaves of Lippia sidoides led to the isolation of: steroid β-sitosterol, naphthoquinone tecomaquinone, monoterpene carvacrol, flavonoid 4',5,7-trihydroxyflavanone (naringenin), 3',4',5,7-tetrahydroxyflavanone and 4',5,7-trihydroxy-6-methoxyflavone flavonoids mixture, and 3,4,4',6'-tetrahydroxydihydrochalcone-2'-O-β-D-glucopyranoside and 4,4',6'-trihydroxydihydrochalcone-2'-O- β-D-glucopyranoside dihydrochalcones mixture. Their structures were characterized on the basis of spectral data, mainly ¹H and 13C NMR (1D and 2D) and mass spectra. The ethanol extract and isolated compounds were evaluated for their antioxidative properties using the method of inhibition of free radical DPPH (2,2-diphenyl-1-picrylhydrazyl).

Flavonoides de Lonchocarpus campestris (Leguminosae)

A new flavone named 3,4',5,6-tetramethoxy-[2'',3'':7,8]furanoflavone besides the known flavonoids (2S,3R,4S)-3,4,5,8-tetramethoxy-[2'',3'':6,7]-furanoflavan, 3,6-dimethoxy-2'',2''-dimethylcromene-[2'',3'':7,8] -flavone, 3,5,6-trimethoxy-[2'',3'':7,8]-furanoflavone, 2,4',4,5-tetramethoxy-[2'',3'':6,7]-furanodihydroaurone, (2R,3S,4S)-3,4,5,6-tetramethoxy-[2'',3'':7,8]-furanoflavan and 3',4'-methylenodioxy-5,6-dimethoxy-[2'',3'':7,8]-furanoflavone were isolated from the root barks of Lonchocarpus campestris. The complete ¹H and 13C NMR assignments of the new furan flavonoid was performed using 1D and 2D pulse sequences, including COSY, HMQC and HMBC experiments.