From the natural product 4-(4'-O-acetyl-α-L-rhamnosyloxy)benzylisothiocyanate (1), isolated from the flowers of Moringa oleifera Lam (Moringaceae), four new semisynthetic derivatives, N-[4-(4'-O-acetyl-α-L-rhamnosyloxy)benzyl]-2-(pyridinil-4-carbonil)hydrazine-1-carbothioamide (3), 4-(4'-O-acetyl-2',3'-dimesyloxy-α-L-rhamnosyloxy)benzylisothiocyanate (4), N-[(4'-O-acetyl-α-L-rhamnosyloxy)benzyl]hydrazinecarbothioamide (5), 4-[4'-O-acetyl-2',3'-O-bis(decanoiloxy)-α-L-rhamnosyloxy]benzylisothiocianate (6), and the known compound 4-(2',3',4'-O-triacetyl-α-L-rhamnosyloxy)benzylisothiocyanate (2), were obtained. All compounds were tested for their cytotoxicity against the tumor cell lines SF-295, HL-60, HCT-116 e PC-3. The natural product 1 and the semisynthetic derivatives 2 and 4 were the most active compounds (IC50 from16.0 to 3.7 µmol L-1) against all tumor cell lines.
The VOCs produced by the Albonectria rigidiuscula fungus in different conditions were obtained by headspace-solid phase microextraction (HS-SPME) and analyzed by gas chromatography-mass spectrometry (GC-MS). Fourty-four VOCs were identified in different culture media and incubation periods. The highest production of VOCs occurred in solid rice medium and 14 days of incubation. The compounds 3-methylbutan-1-ol, 2-methylbutan-1-ol, γ-muurolene and nerolidol acetate were produced by A. rigidiuscula in all culture conditions. γ-Muurolene was identified as the major compound (40.78%, 26.24% and 27.04%) in PD medium and it was suggested as a chemical marker for this fungus. The use of multivariate data analysis (PCA) and (HCA) allowed the discrimination of the volatile chemical profiles according to the culture medium.
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.
Intermolecular forces are a useful concept that can explain the attraction between particulate matter as well as numerous phenomena in our lives such as viscosity, solubility, drug interactions, and dyeing of fibers. However, studies show that students have difficulty understanding this important concept, which has led us to develop a free educational software in English and Portuguese. The software can be used interactively by teachers and students, thus facilitating better understanding. Professors and students, both graduate and undergraduate, were questioned about the software quality and its intuitiveness of use, facility of navigation, and pedagogical application using a Likert scale. The results led to the conclusion that the developed computer application can be characterized as an auxiliary tool to assist teachers in their lectures and students in their learning process of intermolecular forces.
Volatile organic compounds (VOCs) from ten endophytic fungal species belonging to the Botryosphaeriaceae family were extracted by headspace-solid phase micro-extraction (HS-SPME) and analyzed by gas chromatography-mass spectrometry (GC-MS). Thirty-four VOCs were identified. Most of the compounds are sesquiterpenes (14 non-oxygenated and 10 oxygenated), and two linear ketones and eight alcohols were also identified. Multivariate data analysis (PCA and HCA) allowed the differentiation of all investigated species, and proved to be efficient for the differentiation of Neofusicocum parvum and N. ribis, which are considered very similar species. α-Bisabolol, α-selinene, α-cedrene epoxide and guaiol acetate were suggested as biomarkers.
The diterpene ent-18,19-dihydroxytrachylobane was biotransformed for the first time by Rhizopus stolonifer, and yielded the new ent-11β,18,19-trihydroxytrachylobane derivative besides the new ent-kaur-11-ene diterpenes ent-16α,18,19-trihydroxykaur-11-ene and ent-18,19-dihydroxy-16α-methoxykaur-11-ene. Their structures were determined by spectrometric methods.
Stemodinol, a new natural compound, together with known compounds including jaceidin, stemodin, stemodinoside B, isocrenatoside, verbascoside, crenatoside, and isoverbascoside, were isolated from Stemodia maritima Linn. The antioxidant (DPPH method) and antimicrobial activities of stemodin, stemodinoside B, and crenatoside were investigated. Among the components tested, only crenatoside isolated from the roots showed a high antioxidant power. Stemodin and stemodinoside B exhibited antibacterial activities.
In the search for new larvicides from plants, we have investigated the potential activity of the rotenoids deguelin (1), 12a-hydroxy-α-toxicarol (2) and tephrosin (3), isolated from the bioactive ethanol extract of roots of Tephrosia toxicaria Pers., against Aedes aegypti, the main vector of dengue. The absolute configuration of these compounds was determined by circular dichroism (CD) spectra. The LC50 values of the compounds evaluated justify the potential of T. toxicaria as a new natural larvicide.
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.
The increase in the incidence of fungal infections and the frequent report of resistance and therapeutic failure has promoted the performance of phytochemical screening for compounds with antifungal properties. Based on this, the present study investigated the antifungal potential of extracts of Baccharis ligustrina, B. schultzii, Croton jacobinensis, Licania rigida, Moringa oleifera, Vernonia sp. and V. brasiliana and of essential oils of Lippia alba (Chemotypes 1, 2, 3 and 4) and Ocimum gratissimum. Initially, a qualitative evaluation of the antifungal activity of each vegetal sample against strains of Candida albicans and Microsporum canis, through the agar diffusion method, was performed. Extracts of M. oleifera (MLF-C) and Vernonia sp. (TVS-H) presented activity against C. albicans and M. canis with inhibition halos =10mm. Then, minimum inhibitory concentrations (MICs) for MLF-C and TVS-H against 12 strains of C. albicans and M. canis were determined through the methodology established by the Clinical and Laboratory Standards Institute (CLSI), and acute toxicity tests against Artemia sp. were performed for both extracts. MICs (80%) for MLF-C and TVS-H varied from 0.156 to 2.5mg mL-1 against C. albicans and from 0.039 to 1.25mg mL-1 and 0.039 to 0.625mg mL-1 against M. canis, respectively. MICs (100%) for MLF-C and TVS-H varied from 0.625 to 2.5mg mL-1 for C. albicans and from 0.039 to 2.5mg mL-1 and 0.078 to 1.25mg mL-1 against M. canis, respectively. Lethal doses (DL50) of MLF-C and TVS-H were 201.09 and 204.17mg mL-1, respectively, being, therefore, demonstrated the low toxicity of these extracts. M. oleifera and Vernonia sp. extracts presented in vitro antifungal activity against C. albicans and M. canis, creating perspectives for the development of studies on the characterizations of their bioactive components.
O aumento da incidência das infecções fúngicas, bem como o registro crescente de resistência e falha terapêutica, têm impulsionado a realização de estudos de prospecção de fitoquímicos com propriedades antifúngicas. Diante do exposto, o presente estudo investigou o potencial antifúngico de extratos de Baccharis ligustrina, B. schultzii, Croton jacobinensis, Licania rigida, Moringa oleifera, Vernonia sp. e V. brasiliana, e de óleos essenciais de Lippia alba (Quimiotipos 1, 2, 3 e 4) e Ocimum gratissimum. Inicialmente, foi realizada uma avaliação qualitativa da atividade antifúngica de cada amostra por meio do método de difusão em ágar, frente a cepas de Candida albicans e Microsporum canis, mostrando que apenas os extratos de M. oleifera (MLF-C) e Vernonia sp. (TVS-H) apresentaram atividade frente a C. albicans e M. canis, com halos de inibição =10mm. Também foram determinadas a concentração inibitória mínima (CIM), frente a 12 cepas de C. albicans e M. canis, e a toxicidade aguda de MLF-C e TVS-H, através de protocolos do Clinical and Laboratory Standards Institute (CLSI) e ensaio com Artemia sp., respectivamente. A CIM (80%) de MLF-C e TVS-H variou de 0,156 a 2,5mg mL-1 frente C. albicans e de 0,039 a 1,25 e 0,039 a 0,625mg mL-1 para M. canis, respectivamente. A CIM (100%) de MLF-C e TVS-H variou de 0,625 a 2,5mg mL-1 frente C. albicans é de 0,039 a 2,5 e 0,078 a 1,25mg mL-1 para M. canis, respectivamente. As doses letais (DL50) para o MLF-C e TVS-H foram de 201,09 e 204,17mg mL-1, respectivamente, sendo, portanto, demonstrada a baixa toxicidade desses extratos. Os extratos de M. oileifera e Vernonia sp. apresentaram atividade antifúngica frente cepas de C. albicans e M. canis, abrindo a perspectiva de estudos para caracterização dos seus componentes bioativos.
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.
Um novo diterpeno, (5S*,8S*,9R*,10S*)-11β,12β-epoxi-9α-hidróxi-19(4→3) abeo-abieta-3,13-dieno-19,18-olideo, e as substâncias conhecidas estemodina, D-manitol, ácido betulínico, uma mistura de 3β-O-β-D-glicopiranosil-β-sitosterol e 3β-O-β-D-glicopiranosilestigmasterol, e 5,7,4'-triidróxi-3,8,3'-trimetoxiflavona, foram isolados das folhas e talos de Stemodia maritima. A elucidação estrutural de todas as substâncias baseou-se na interpretação de dados espectrais, principalmente RMN (1D e 2D) e espectrometria de massa (EM), envolvendo comparação com valores descritos na literatura.
The ethanol extracts from leaves, stems, pods and roots were assayed against the 3rd instar Aedes aegypti larvae and the highest activity was observed in the roots extracts (LC50 47.86 ppm). This extract was submitted to partition with hexane, chloroform, ethyl acetate and methanol. The respective fractions were bioassayed and the best larvicidal activities were identified in the hexane (LC50 23.99 ppm) and chloroform (LC50 13.80 ppm) fractions. Antioxidant activity (DDPH method) was observed in the ethanol extract (IC50 276 µg/mL) from roots of T. toxicaria. Fractions from this extract were also tested and the highest antioxidant activity (IC50 89 µg/mL) was found in the methanol fraction. The flavonoids iso-obovatin (1), obovatin (2), 6a,12a-dehydro-β-toxicarol (3), 6a,12a-dehydro-α-toxicarol (4) and α-toxicarol (5) were isolated and bioassayed against A. aegypti. The flavonoid 5 showed the best larvicidal activity (LC50 24.55 ppm). The antioxidant activity of 2 was investigated and showed IC50 3.370 µg/mL. The antioxidant and larvicidal activities of Tephrosia toxicaria are reported for the first time.
The phytopatogenic fungus Lasiodiplodia theobromae, isolated from guava, was cultivated in rice for 32 days at room temperature. Extraction with CH2Cl2:MeOH (3:7), followed by chromatography fractionation of the extract provided ergosterol. From the fungus culture in Czapeck medium for 40 days at room temperature, were isolated isocoumarin cis-4-hydroxymeleine and an eremophilane-type sesquiterpene. The latter compound is being reported for the first time in the literature. Also, this is the first time that an eremophilane sesquiterpene is described for Lasiodiplodia genus.
O fungo fitopatogênico Lasiodiplodia theobromae, isolado de goiaba, foi cultivado em arroz por 32 dias à temperatura ambiente. Extração com CH2Cl2:MeOH (3:7), seguido de fracionamento cromatográfico do extrato forneceu o esteróide ergosterol. Da cultura fúngica em meio de Czapeck por 40 dias à temperatura ambiente, foram isolados a isocumarina cis-4-hidroximeleína e um sesquiterpeno do tipo eremofilano. O sesquiterpeno eremofilano está sendo descrito pela primeira vez na literatura. Este é o primeiro relato do isolamento de um sesquiterpeno eremofilano para o gênero Lasiodiplodia.
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.
The investigation of the ethyl acetate fraction of methanol extract from leaves of Almeidea rubra A. St.-Hil. (Rutaceae) afforded two new compounds 4-methoxy-6-[2-(methylamino)phenyl]-2H-pyran-2-one and rel-(7R,8R)-8-[(E)-3-hydroxy-3-methyl-1-butenyl]-4,8-dimethoxy-5,6,7,8 -tetrahydrofuro[2,3-b]quinoline-7-yl acetate, along with the known compounds arborinine, N-methyl-1-hydroxy-3-methoxyacridone, skimmianine, kokusagine, isodutaduprine, isoskimmianine, and isokokusagine. Their structures were established based on their spectral data, and for the new compounds these data are described herein. Additionally, these compounds were assayed on the tripomastigote forms of Trypanosoma cruzi showing moderate trypanocidal activity.
O estudo da fração acetato de etila do extrato metanólico das folhas de Almeidea rubra A. St.-Hil. (Rutaceae) permitiu o isolamento de duas substâncias inéditas: 4-metoxi-6-[2-(metilamino)fenil]-2H-piran-2-ona e acetato de rel-(7R,8R)-8-[(E)-3-hidroxi-3-metil-1-butenil]-4,8-dimetoxi-5,6,7,8 -tetraidrofuro[2,3-b]quinolin-7-ila; e dos alcalóides arborinina, N-metil-1-hidroxi-3-metoxiacridona, esquimianina, cocusagina, isodutaduprina, isoesquimianina e isococusagina. Através da análise dos dados espectroscópicos foram estabelecidas as estruturas químicas das substâncias isoladas sendo que para os alcalóides inéditos tais dados são descritos pela primeira vez. Além disso, os ensaios bilógicos sobre as formas tripomastigotas do Trypanosoma cruzi das substâncias isoladas mostraram que elas possuem atividade tripanocida moderada.