Chemical characterization, cytotoxicity, antimicrobial and antioxidant potential of Justicia pectoralis Jacq and Croton jacobinensis Baill extracts

Abstract In this research, aqueous and ethanolic extracts from Justicia pectoralis Jacq and Croton Jacobinensis Baill were characterized. The UPLC-QTOF-MSE analysis was performed on the extracts identified, predominantly, flavonoids, tannins and acids. The extracts did not indicate toxicity in human epithelial cells. C. jacobinensis presented a concentration of phenolics 60.5% higher than J. pectoralis in all scenarios evaluated and, for both samples, the hydroalcoholic extract at 70% exhibited the best efficiency in the extraction (14501.3 and 32521.5 mg GAE 100 g-1 for J. pectoralis and C. jacobinensis, respectively). The antioxidant activity presented a positive correlation with the concentration of phenolics, being 1.186,1 and 1.507,9 µM of Trolox for J. pectoralis and C. jacobinensis at 70% of ethanol; however, it was not verified statistical difference between the ethanolic solutions (p < 0.05). The antimicrobial activity of J. pectoralis extracts was highlighted once was the most effective against gram-positive bacteria. The results suggest that both J. pectoralis and C. jacobinensis extracts present the potential to be applied as natural additives due to their antioxidant and antimicrobial activity and safety. Thus, it is suggesting the development of studies that could investigate the interaction of these plant extracts with food matrices is required

Antibacterial activity of the alkaloid extract and isolated compounds from Croton bonplandianum Baill. (Euphorbiaceae) / Atividade anti-bacteriana do extrato alcaloide e de compostos isolados de Croton bonplandianum Baill. (Euphorbiaceae)

ABSTRACT The antibacterial activity of the alkaloid extract from the leaves of Croton bonplandianum Baill. and its main compounds, sparsiflorine and crotsparine, was tested against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa by the resazurin microtitre-plate method. Pure compounds were identified by spectroscopic techniques, mainly 1D and 2D NMR. The alkaloid extract showed activity particularly against the S. aureus and P. aeruginosa. Regarding the pure compounds, the crotsparine was inactive against the microorganisms assayed, whereas the sparsiflorine indicated a moderate activity similar to the alkaloid extract. The Pseudomonas aeruginosa was the most sensitive of the tested microorganisms with MIC of 0.141 mg/mL. The results suggest that the activity of the extract may be credited mainly to the presence of the sparsiflorine. Although the activity of the sparsiflorine does not get close to the antimicrobial drugs in clinical use, it still could be a lead compound for the development of new antibacterial substances.

RESUMO A atividade antibacteriana do extrato alcaloidal das folhas de Croton bonplandianum Baill., além dos principais compostos isolados, esparsiflorina e crotsparina, foi testada contra Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae e Pseudomonas aeruginosa. Foi utilizado o método de microdiluição em placa empregando resazurina como indicador da viabilidade celular. Os compostos isolados foram identificados por técnicas espectroscópicas, principalmente RMN 1D e 2D. O extrato alcaloidal foi ativo principalmente contra S. aureus e P. aeruginosa. Crotsparina mostrou-se inativa contra todos os micro-organismos testados, enquanto esparsiflorina apresentou atividade moderada, a qual foi similar à do extrato bruto. Pseudomonas aeruginosa foi a mais sensível das bactérias testadas, com CIM de 0,141 mg/mL. Os resultados sugerem que a atividade do extrato pode ser devida em grande medida pela presença de esparsiflorina. Apesar de a CIM da esparsiflorina não ter se aproximado daquela apresentada pelos agentes antimicrobianos em uso clínico, tal composto ainda pode compor um protótipo interessante para o desenvolvimento de novas substâncias antibacterianas.

Chemical Composition of the Leaf Essential Oils of Croton zambesicus Müll.-Arg. Grown in Lagos, South-West Nigeria.

The chemical composition of the leaf essential oil of Croton zambesicus Müll.-Arg., collected from Agbara-Lagos, Nigeria, was analysed by means of Gas chromatography flame ionization detector (GC-FID) and Gas chromatography coupled with Mass spectrometry (GC-MS). Sixty constituents accounting for 98.9% of the total oil contents were identified from the oil sample. The classes of compounds identified in the oil were monoterpene hydrocarbons (35.3%), oxygenated monoterpenes (22.9%), sesquiterpene hydrocarbons (32.4%) and oxygenated sesquiterpenes (5.6%). The oil was dominated by β-pinene (15.1%), β-caryophyllene (12.6%), germacrene D (10.9%), camphor (7.3%), linalool (7.0%), sabinene (6.4%) and α-pinene (5.2%). Aims: The aim of the research is to investigate the volatile constituents from C. zambesicus harvested in Lagos, Nigeria. Study Design: Extraction of essential oil from the air-dried leaf samples of C. zambesicus and investigation of its chemical constituents. Place and Duration of Study: Leaf samples of C. zambesicus were collected from Agbara, Lagos, on April 2011. Methodology: Air-dried and pulverized leaves were hydrodistilled in a Clevenger-type apparatus to obtained pale yellow volatile oil whose chemical constituents was analyzed by GC and GC/MS. Results: A total of sixty compounds were identified, amounting to 98.9%of the total oil contents. The major were compounds β-pinene (15.1%), β-caryophyllene (12.6%), germacrene D (10.9%) and camphor (7.3%). Variations in compositional pattern were observed between this result and the previous studies. Conclusion: The literature about the C. zambesicus indicates a high variability in the chemical composition of the essential oils.

As espécies de Croton L. sect. Cyclostigma Griseb. e Croton L. sect. Luntia (Raf.) G. L. Webster subsect. Matourenses G. L. Webster (Euphorbiaceae s.s.) ocorrentes na Amazônia brasileira / Species of Croton L. sect. Cyclostigma Griseb. and Croton L. sect. Luntia (Raf.) G. L. Webster subsect. Matourenses G. L. Webster (Euphorbiaceae s.s.) occuring within Brazilian Amazon

Como parte de uma revisão taxonômica das espécies de Croton L. na Amazônia brasileira, estudou-se as seguintes espécies de Croton sect. Cyclostigma Griseb. e Croton sect. Luntia (Raf.) G. L. Webster subsect. Matourenses G. L. Webster: Croton urucurana Baill., C. draconoides Müll. Arg., C. trombetensis R. Secco, P. E. Berry & N.A. Rosa, C. sampatik Müll. Arg., C. palanostigma Kl., C. pullei Lanj. e C. matourensis Aubl. O estudo foi baseado em trabalho de campo realizado nos Estados do Pará e Maranhão, e em material depositado nos herbários IAN, INPA, MG e RB, incluindo tipos. Algumas dessas espécies, como C. urucurana, C. draconoides, C. palanostigma e C. sampatik , são frequentemente encontradas nos herbários com identificações equivocadas. São discutidas a posição taxonômica das espécies nas seções e suas afinidades, e uma chave dicotômica e ilustrações foram elaboradas para um melhor entendimento dos táxons.

As part of a taxonomic revision of Brazilian Amazonia species of Croton L., the following species of Croton sect. Cyclostigma Griseb. and Croton sect. Luntia (Raf.) G. L. Webster subsect. Matourenses G. L. Webster were studied: Croton urucurana Baill., C. draconoides Müll. Arg., C. trombetensis R. Secco, P. E. Berry & N.A. Rosa, C. sampatik Müll. Arg., C. palanostigma Kl., C. pullei Lanj. and C. matourensis Aubl. This study was based on field work in the States of Pará and Maranhão, and material deposited in herbaria IAN, INPA, MG e RB, including the types. Some of the species, such as C. urucurana, C. draconoides, C. palanostigma, and C. sampatik , are frequently found with misidentification in herbaria. The taxonomic position of the species within sections and their affinities are discussed, and a dychotomic key and illustrations were elaborated for a better understanding of the taxa.

Revisão taxonômica de Croton sect. Lamprocroton (Müll. Arg.) Pax (Euphorbiaceae s.s.) / Taxonomic revision of Croton sect. Lamprocroton (Müll. Arg.) Pax (Euphorbiaceae s.s.)

Croton is the second bigger and more diverse genus in the family Euphorbiaceae, with about 1,200 species distributed in 40 sections, occurring in all tropical areas, most of them in Americas. In South America, Brazil is the country in which a larger number of taxa are found, ca. 356. According to recent classification, the genus belongs to the tribe Crotoneae, and despite the wide and morphological diversity, it would be a monophyletic taxon. However, a phylogenetic analysis using markers of ITS region from nuclear ribosomal DNA, and of trnL-F from plastidial DNA, showed that Croton, like traditionally circumscribed, is not a monophyletic taxon. A taxonomic revision of Croton section Lamprocroton (Müll. Arg.) Pax is presented here. It is a Neotropical group with most of its species occurring from Southeast and South Brazil to southern South America (Uruguay and Argentina). Morphologically, the members of Lamprocroton are characterized as monoecious or dioecious shrubs or subshrubs, with a lepidote indumentum at least in part of foliage, entire leaves with no glands. The staminate flowers have 9 to 16 stamens and the pistillate flowers may have equal or unequal sepals, reduced to absent petals, and styles once or twice bifid. Overall, are recognized 26 species in the group, three of them new to the science. Identification key, morphological descriptions, illustrations, phenological period, as well as data on geographic distribution and general comments of each species are presented. Four taxa were excluded from C. sect. Lamprocroton because they do not show the morphological features that are diagnostics of the section. Four species that are poorly known were not included in the taxonomic treatment.

O gênero Croton L. é o segundo maior e mais diverso da família Euphorbiaceae, possuindo cerca de 1.200 espécies, agrupadas em 40 seções, com distribuição pantropical, das quais a maioria ocorre nas Américas. Na América o Sul, o Brasil é o país que congrega o maior número de espécies, aproximadamente 356. De acordo com a mais recente classificação, o gênero pertence à tribo Crotoneae e, apesar do grande número de espécies e da grande diversidade morfológica, seria um táxon monofilético. Entretanto, uma análise filogenética recente, que utilizou dados moleculares das regiões ITS, do DNA nuclear ribossômico, e do fragmento trnL-F, do DNA plastidial, demonstrou que Croton, como tradicionalmente circunscrito, não é um táxon monofilético. Neste trabalho, é apresentada uma revisão taxonômica de Croton sect. Lamprocroton (Müll. Arg.) Pax. Trata-se de um grupo neotropical com a maioria das espécies ocorrendo nas regiões Sudeste e Sul do Brasil e sul da América do Sul. Seus representantes caracterizam-se por ser plantas arbustivas ou subarbustivas, monóicas ou dióicas, com indumento lepidoto presente em pelo menos parte da folhagem e folhas inteiras e sem glândulas. As flores estaminadas possuem androceu composto por 9 a 16 estames e as flores pistiladas apresentam sépalas iguais ou desiguais no tamanho, pétalas reduzidas ou ausentes e estiletes uma ou duas vezes bífidos. Neste trabalho são reconhecidas 26 espécies na seção sendo três novas para a ciência. Chave de identificação, descrições morfológicas, ilustrações, período fenológico, distribuição geográfica e comentários gerais de cada uma das espécies são apresentados. Quatro táxons foram excluídos de C. sect. Lamprocroton por não possuírem os caracteres morfológicos diagnósticos da seção. Quatro espécies não foram incluídas no tratamento taxonômico por falta de informação sobre as mesmas.