ABSTRACT The cultivation of sugarcane hybrids (X Saccharum officinarum L.) is an important revenue source for the Brazilian economy. Herein it is reported the evaluation of the cytotoxic activity of mid-polarity sugarcane extracts against human cancer cell lines, as well as the isolation of steroids sitosterol, stigmasterol and campesterol, phenolic acids p-hydroxybenzoic, p-hydroxycinnamic, vanillic and ferulic acid, terpenoids α-tocopherol and β-carotene and a novel substance in sugarcane, the flavonoid aglycone tricin (5,7,4-trihydroxy-3,5-dimethoxyflavone). The presence of large amounts of phenolic acids and the flavonoid tricin may explain the cytostatic activity observed for the mid-polarity crude extract and filtrates.

The isolation and structure determination of new cyclic peptide alkaloid ixorine, along with five known constituents frangulanine, syringaresinol, cinnamtannin B-1, daucosterol and mannitol from the branches of Ixora brevifolia are described. The cyclic peptide frangulanine is being described for the first time in the Rubiaceae family. The structures were elucidated on their spectral data basis, mainly one- (1H, 13C, DEPT) and two-dimensional (COSY, NOESY, HSQC and HMBC) nuclear magnetic resonance (NMR) and by comparison with data from the literature. The mixture of two cyclopeptide alkaloids showed weak activity against Leishmania amazonensis.

The chemical study of the orchid Maxillaria picta resulted in the isolation of the bioactive stilbenes phoyunbene B and phoyunbene C, in addition to four phenolic acids, one xanthone, steroidal compounds and two triterpenes. Crude extract, fractions, subfractions and the isolated xanthone were evaluated for anticancer activity against human tumor cell lines and against evolutionary forms of T. cruzi and L. amazonensis. The structures of the compounds were determined by GC-MS, and ¹H NMR, 13C NMR spectral methods as well as bidimensional techniques.

Pisonia aculeata L. (Nyctaginaceae) is a shrub widely used in Brazilian folk medicine, where the roots are used as purging and barks and leaves have anti-inflammatory properties. The aim of this study is to evaluate the antiedematogenic activity of crude extract and derived fractions from stems of P. aculeata and the acute toxicity of crude methanolic extract. From methanolic extract from stems of P. aculeata were obtained steroids, triterpenoids and nitrogenous compounds. All fractions tested show inhibitory activity of mice edema ear induced by croton oil, mainly hexane and chloroform fractions. Crude methanolic extract was also active, inhibiting 27.9% of the swelling occasioned by croton oil. In addition, treatment of mice with the crude extract of the stems of P. aculeata in the acute toxicity test did not cause death of animals or change in behavioral parameters, indicating that the extract may be considered non-toxic.

Pisonia aculeata L. (Nyctaginaceae) es un arbusto ampliamente utilizado en la medicina popular de Brasil, donde las raíces se utilizan como purgante, mientras que la corteza y hojas por sus propiedades anti-inflamatorias. El objetivo de este estudio es evaluar la actividad antiedematogénica del extracto crudo y las fracciones derivadas de los tallos de P. aculeata y la toxicidad aguda del extracto metanólico crudo. Del extracto metanólico obtenido de los tallos de P. aculeata se obtuvieron esteroides, triterpenoides y compuestos nitrogenados. Todas las fracciones probadas mostraron antiinflamatoria actividad en el edema de oreja inducido por aceite de crotón en ratones, sobre todo las fracciones de hexano y cloroformo. El extracto metanólico crudo también fue activo, inhibiendo el 27,9% de la inflamación ocasionada por el aceite de crotón. Además, el extracto crudo de los tallos de P. aculeata en el ensayo de toxicidad aguda no causaron la muerte de los animales o el cambio en su comportamiento, lo que indica que el extracto puede ser considerado como no tóxico.

A continuidade do estudo fitoquímico de P. prunifolia com a análise dos extratos etanólicos obtidos a partir de suas raízes e galhos levou ao isolamento de cinco alcaloides indol-β-carbolínicos dos quais, dois derivados, o 10-hidróxi-iso-deppeaninol e o N-óxido-10-hidróxi-antirhina são descritos pela primeira vez. As estruturas foram determinadas por análise de técnicas espectroscópicas de IV, EMAR e RMN (¹H e 13C, 1D e 2D). A avaliação da atividade frente à Leishmania amazonensis e Trypanosoma cruzi, mostrou que os extratos brutos e os alcaloides 14-oxoprunifoleína e estrictosamida inibiram as formas promastigotas de L. amazonensis, com valores de CI50 de 16,0 e 40,7 µg per mL, respectivamente.

The continuity of the phytochemical study of crude extracts of P. prunifolia's roots and branches led to the isolation of five indole-β-carboline alkaloids. Among them, the 10-hydroxy-iso-deppeaninol and N-oxide-10-hydroxy-antirhine derivatives are described here for the first time. The structures were achieved through 1D and 2D NMR, IR and HRMS analyses. The branches and roots crude extracts and the alkaloids 14-oxoprunifoleine and strictosamide showed selective activity against L. amazonensis, with IC50 values of 16.0 and 40.7 µg per mL, respectively.

A atividade antioxidante, avaliada pelo método DPPH (1,1-difenil-2-picrilidrazila), e o teor em compostos fenólicos totais do extrato bruto metanólico e frações das folhas da espécie Palicourea rigida Kunth, Rubiaceae, foram quantificadas neste trabalho. Apesar da baixa atividade apresentada pelo extrato bruto (500 ppm), a fração acetato de etila apresentou atividade moderada (192 ppm) e o maior teor de fenólicos totais dentre as frações ensaiadas. Assim, a fração acetato de etila foi submetida a procedimentos cromatográficos o que resultou no isolamento dos flavonoides quercetina 3-O-β-D-glicosídeo, quercetina 3-O-soforosídeo e isoraminetina 3-glicosídeo, cujas estruturas foram elucidadas por análise espectroscópica, incluindo RMN (1D e 2D) e comparação com os dados da literatura.

The antioxidant activity, evaluated by DPPH (1,1-difenil-2-picrilidrazila) method, and the determination of the total phenolic compounds of the crude methanolic extract and fractions of the Palicourea rigida Kunth, Rubiaceae, leaves were quantified in this work. Despite weak activity exhibited by crude extract (500 ppm), the fraction ethyl acetate showed moderate activity (192 ppm), and the largest value for the phenolic compounds among all the assayed fractions. Then, the ethyl acetate fraction was submitted to the chromatography procedures which led to the isolation of the flavonoid quercetin 3-O-D-glicoside, quercetin 3-O-sophoroside and isorhamnetin 3-glicoside, which had the structures elucidated by spectroscopy analysis, including RMN (1D and 2D) and comparison with literature data.

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.

Dois novos diterpenos do tipo abietano 3beta-hidroxi-9alfa, 13alfa-epidioxiabiet-8(14)-eno (1) e 3-oxo-9alfa,13alfa-epidioxiabiet-8(14)-eno (2) foram isolados do extrato bruto metanólico dos pecíolos de Sagittaria montevidensis ssp montevidensis (Alismataceae). As estruturas de 1 e 2 foram determinadas com base em análises espectrométricas do tipo EM-AR, IV, bem como, RMN de ¹H e 13C uni e bi dimensionais.

Two new abietane-type diterpenes, 3beta-hydroxy-9alpha, 13alpha-epidioxyabiet-8(14)-ene (1) and 3-oxo-9alpha,13alpha-epidioxyabiet-8(14)-ene (2), were isolated from the methanolic crude extract of the petioles of Sagittaria montevidensis ssp montevidensis (Alismataceae). The structures of 1 and 2 were determined on the basis of spectrometric analyses including HREIMS, IR as well as ¹H and 13C 1 and 2D NMR.

No presente trabalho descrevemos a síntese e a avaliação da atividade antiproliferativa, frente a linhagens de células tumorais humanas, de derivados do R-(+)-limoneno (3-18) contendo uma unidade tiouréia substituída. Os derivados com substituintes arílicos (3-6) exibiram atividade citostática frente a todas linhagens testadas, com inibição de 50% do crescimento celular (GI50) em concentrações na faixa de 2,5 a 24 µmol L-1. Os compostos 3, 10, 12 e 16 foram os mais ativos, com GI50 na faixa de 0,41 a 3,0 mmol L-1, frente a diferentes linhagens celulares.

A series of R-(+)-limonene derivatives bearing a substituted thiourea moiety (3-13) and five S-methyl analogs (14-18) were synthesized and evaluated for their in vitro antiproliferative activity against human cancer cell lines. Compounds bearing aromatic substituents (3-6) exhibit cytotastic activity in the full panel of cell lines tested, with GI50 values in the range of 2.5 to 24 µmol L-1. Compounds 3, 10, 12 and 16 were the most active with GI50 values in the range of 0.41 to 3.0 µmol L-1, against different cell lines.

As folhas de Hyptis ovalifolia Benth. (Lamiaceae) foram submetidas à hidrodestilação e a fração volátil foi investigada por CG/EM. O componente principal, (R)-6-[(Z)-1-heptenila]-5,6-diidro-2H-piranona (1), representando 60% do óleo essencial, foi isolado por cromatografia em coluna e identificado por métodos espectroscópicos. O composto mostrou atividade in vitro contra 4 espécies (60 isolados clínicos) dos dermatófitos: Microsporum canis, Microsporum gypseum, Tricophyton mentagrophytes e Tricophyton rubrum com concentração inibitória mínima variando de 125-7,8 µg mL-1.

The leaves of Hyptis ovalifolia Benth. (Lamiaceae) were subjected to hydrodistillation and the resulting volatiles were investigated by GC/MS. The main constituent representing 60% of the essential oil was isolated by column chromatography and identified by spectroscopic methods as (R)-6-[(Z)-1-heptenyl]-5,6-dihydro-2H-pyran-2-one (1). This compound showed strong in vitro activity against four dermatophyte fungi Microsporum canis, Microsporum gypseum, Tricophyton mentagrophytes, and Tricophyton rubrum (a total of 60 strains) with a minimal inhibitory concentration observed in the range of 125-7.8 mg µL-1.

Um extrato metanólico das folhas de Luehea divaricata (Tiliaceae), vulgarmente conhecida no Brasil como "açoita-cavalo", forneceu um novo triterpeno caracterizado como ácido 3beta-p-hidroxibenzoiloxitormentico [ácido 3beta-(p-hidroxibenzoiloxi)-2alfa-hidroxiurs-12-en-28-óico], juntamente com uma mistura contendo o ácido maslínico, um triterpeno conhecido. As estruturas dos compostos foram estabelecidas por métodos espectroscópicos.

A methanolic extract from leaves of Luehea divaricata (Tiliaceae), known in Brazil as "açoita-cavalo", yielded two triterpene: a novel characterized as 3beta-p-hydroxybenzoyloxytormentic acid [3beta-(p-hydroxybenzoyloxy)-2alpha-hydroxyurs-12-en-28-oic acid] and a mixture containing the maslinic acid. The new compound's structure was established by spectroscopic methods.

A reatividade de duplas ligações terminal e trissubstituída de monoterpenos com HSCN foi examinada por CG evidenciando que fatores cinéticos são responsáveis pela adição quimiosseletiva em duplas ligações terminais em terpenos. O resultado mostra que a adição é cerca de 17 vezes mais rápida em duplas terminais do que em duplas trissubstituídas e que a presença do primeiro grupo SCN impede a entrada de um segundo grupo. A presença de um grupo hidroxila ou metoxila na molécula diminui sensivelmente a velocidade da reação. A partir do estudo acima foi possível elaborar e realizar a síntese do produto natural 7-isothiocyano-7,8-dihydro-alfa-bisabolene em duas etapas a partir do bisabolol.

The reactivity of terminal and trisubstituted double bonds of monoterpenes with HSCN has been examined by GC giving evidence that kinetics is responsible for the chemoselective addition to terminal double bonds in terpenes. The results show that the addition to the terminal double bond is about 17 times faster than for trisubstituted double bonds and that the presence of the first SCN group in the molecule prevents a second addition. The presence of a hydroxyl or methoxy group in the molecule, decreases the reaction kinetics. Based on these kinetic experiments a two steps synthesis of the natural product 7-isothiocyano-7,8-dihydro-alpha-bisabolene using bisabolol as starting material, was planned and successfully accomplished.

Um novo triterpeno caracterizado como ácido 6alfa-hidroxibetulínico foi isolado das folhas e caule da planta, vulgarmente conhecida no Brasil como Cambuí, Eugenia moraviana (Myrtaceae), juntamente com três outras substâncias conhecidas, identificadas como ácido platânico, ácido betulínico e beta-sitosterol. Através da análise de espectros incluindo NOE e experimentos de RMN em duas dimensões foi realizada a atribuição inequívoca dos deslocamentos químicos de ¹H e de 13C do ácido 6alfa-hidroxibetulínico(ácido-3beta,6alfa-diidróxi-20(29)-lupen-28-óico) e do ácido platânico.

A novel triterpene, characterized as 6alpha-hydroxybetulinic acid, was isolated from the leaves and stems of Eugenia moraviana (Myrtaceae), known in Brazil as Cambuí, together with three known compounds, platanic acid, betulinic acid and beta-sitosterol. Unequivocal ¹H and 13C assignments of 6alpha-hydroxybetulinic acid (3beta,6alpha-dihydroxy-20(29)-lupen-28-oic acid) and platanic acid were undertaken by spectral analysis including NOE and 2 D NMR experiments.