This study describes some characteristics of the Rubiaceae family pertaining to the occurrence and distribution of secondary metabolites in the main genera of this family. It reports the review of phytochemical studies addressing all species of Rubiaceae, published between 1990 and 2014. Iridoids, anthraquinones, triterpenes, indole alkaloids as well as other varying alkaloid subclasses, have shown to be the most common. These compounds have been mostly isolated from the genera Uncaria, Psychotria, Hedyotis, Ophiorrhiza and Morinda. The occurrence and distribution of iridoids, alkaloids and anthraquinones point out their chemotaxonomic correlation among tribes and subfamilies. From an evolutionary point of view, Rubioideae is the most ancient subfamily, followed by Ixoroideae and finally Cinchonoideae. The chemical biosynthetic pathway, which is not so specific in Rubioideae, can explain this and large amounts of both iridoids and indole alkaloids are produced. In Ixoroideae, the most active biosysthetic pathway is the one that produces iridoids; while in Cinchonoideae, it produces indole alkaloids together with other alkaloids. The chemical biosynthetic pathway now supports this botanical conclusion.

Brazil is blessed with a great biodiversity, which constitutes one of the most important sources of biologically active compounds, even if it has been largely underexplored. As is the case of the Amazon and Atlantic rainforests, the Brazilian marine fauna remains practically unexplored in the search for new biologically active natural products. Considering that marine organisms have been shown to be one of the most promising sources of new bioactive compounds for the treatment of different human diseases, the 8000 km of the Brazilian coastline represents a great potential for finding new pharmacologically active secondary metabolites. This review presents the status of marine natural products chemistry in Brazil, including results reported by different research groups with emphasis on the isolation, structure elucidation, and evaluation of biological activities of natural products isolated from sponges, ascidians, octocorals, and Opistobranch mollusks. A brief overview of the first Brazilian program on the isolation of marine bacteria and fungi, directed toward the production of biologically active compounds, is also discussed. The current multidisciplinary collaborative program under development at the Universidade de São Paulo proposes to establish a new paradigm toward the management of the Brazilian marine biodiversity, integrating research on the species diversity, ecology, taxonomy, and biogeography of marine invertebrates and microorganisms. This program also includes a broad screening program of Brazilian marine bioresources, to search for active compounds that may be of interest for the development of new drug leads.

Guarana (Paullinia cupana) is largely consumed in Brazil in high energy drinks and dietary supplements because of its stimulant activity on the central nervous system. Although previous studies have indicated that guarana has some protective effects in Parkinson's (PD), Alzheimer's (AD), and Huntington's (HD) disease models, the underlying mechanisms are unknown. Here, we investigated the protective effects of guarana hydroalcoholic extract (GHE) in Caenorhabditis elegans models of HD and AD. GHE reduced polyglutamine (polyQ) protein aggregation in the muscle and also reduced polyQ-mediated neuronal death in ASH sensory neurons and delayed β-amyloid-induced paralysis in a caffeine-independent manner. Moreover, GHE's protective effects were not mediated by caloric restriction, antimicrobial effects, or development and reproduction impairment. Inactivation of the transcription factors SKN-1 and DAF-16 by RNAi partially blocked the protective effects of GHE treatment in the AD model. We show that the protective effect of GHE is associated with antioxidant activity and modulation of proteostasis, since it increased the lifespan and proteasome activity, reduced intracellular ROS and the accumulation of autophagosomes, and increased the expression of SOD-3 and HSP-16.2. Our findings suggest that GHE has therapeutic potential in combating age-related diseases associated with protein misfolding and accumulation.

Duroia macrophylla popularly known as “cabeça-de-urubú,” “apuruí,” or “puruí-grande-da-mata” occurs in the Amazon Forest. Its leaves and branches were collected twice and extracted with dichloromethane and methanol. All extracts were subjected to phytochemical investigation and terpenes and flavonoids were found in all dichloromethane and methanol extracts, respectively. Methanol extracts from both branches (1st collection) and leaves (2nd collection) presented hydrolyzed tannins, yet alkaloids were only detected in the dichloromethane and methanol extracts from branches at the 2nd collection. Phenol compounds were found in both dichloromethane extracts' collections. The action of every extract was assayed against Mycobacterium tuberculosis (RMPr, H37Rv, and INHr strains), showing that the dichloromethane extract from leaves (1st collection) has the major biological activity, with a MIC of 6.25 μg/mL for the INHr strain, 25.0 μg/mL for the RMPr strain, and ≤6.25 μg/mL for the H37Rv strain. The chromatographic fractioning of the dichloromethane extract from leaves (1st collection) yielded the isolation of two triterpenes: oleanolic and ursolic acids, which were identified by NMR analysis and reported for the first time in the Duroia genus.

BackgroundThe Amazon is the largest rainforest in the world and is home to a rich biodiversity of medicinal plants. Several of these plants are used by the local population for the treatment of diseases, many of those with probable anti-inflammatory effect. The aim of the present investigation was to evaluate the in vitro antioxidant and anti-peroxidases potential of the ethanol extracts of five plants from the Brazilian Amazon (Byrsonima japurensis, Calycophyllum spruceanum, Maytenus guyanensis, Passiflora nitida and Ptychopetalum olacoides).MethodsDPPH, ABTS, superoxide anion radical, singlet oxygen and the β-carotene bleaching methods were employed for characterization of free radical scavenging activity. Also, total polyphenols were determined. Antioxidant activities were evaluated using murine fibroblast NIH3T3 cell. Inhibition of HRP and MPO were evaluated using amplex red® as susbtract.ResultsThe stem bark extracts of C. spruceanum and M. guyanensis provided the highest free radical scavenging activities. C. spruceanum exhibited IC50 = 7.5 ± 0.9, 5.0 ± 0.1, 18.2 ± 3.0 and 92.4 ± 24.8 μg/mL for DPPH•, ABTS+•, O2-• and 1O2 assays, respectively. P. olacoides and C. spruceanum extracts also inhibited free radicals formation in the cell-based assay. At a concentration of 100 μg/mL, the extracts of C. spruceanum, B. japurensis inhibited horseradish peroxidase by 62 and 50 %, respectively. C. spruceanum, M. guyanensis, B. japurensis also inhibited myeloperoxidase in 72, 67 and 56 %, respectively.ConclusionsThis work supports the folk use these species that inhibited peroxidases and exhibited significant free radical scavenging and antioxidant activities what can be related to treatment of inflammation.

Coffee corky-root disease, also called corchosis, was ®rst detected in 1974 in a small area of Costa Rica where the root-knot nematode Meloidogyne arabicida is the dominant species. An epidemiological study revealed a constant association between Meloidogyne spp. and Fusarium sp. in cases of corky root. No corky root appears to have been reported in association with Meloidogyne exigua, which is the prevalent root-knot nematode on coffee in Costa Rica. Fusarium spp. are often cited as components of disease complexes in association with nematodes. Combined inoculations using M. arabicida or M. exigua with Fusarium oxysporum under controlled conditions showed that only the combination with M. arabicida produced corky-root symptoms on Coffea arabica cvs Caturra or Catuai. Fusarium oxysporum alone was nonpathogenic. Meloidogyne exigua or M. arabicida alone caused galls and reduction in shoot height, but no corky-root symptoms. When cultivars susceptible and resistant to M. arabicida were studied under ®eld conditions for 5 years, all the susceptible cultivars exhibited corky-root symptoms on 40±80% of their root systems. Cultivars that were resistant to M. arabicida but not to M. exigua showed no corky root. These observations lead to the conclusion that corky-root disease has a complex etiology, and emphasize the dominant role of M. arabicida as a predisposing agent to subsequent invasion by F. oxysporum. Consequently, genetic resistance to M. arabicida appears to provide an effective strategy against the disease.

No abstract

Recebido em 31/10/97; aceito em 12/5/98 IDENTIFICATION OF COMPONENTS FROM VOLATILE OILS: SPECTROSCOPICAL ANALY-SIS OF SESQUITERPENES MIXTURES. This paper describes a chromatographic method to fractionate volatile oils and to identify their sesquiterpenic constituents. The fractionation process includes flash chromatography over silica gel and chromatography over silica gel/AgNO 3 , utilising pentane, CH 2 Cl 2 and/or acetone as eluents. GC chromatograms were obtained in order to get the relative percentage of each constituent in the volatile oils, to get the retention time value of them as well as to analyse and combine the fractions eluted from the columns. Such procedure afford mixtures of sesquiterpenes which are analysed by GC/MS, 13 C and 1 H NMR.Keywords: volatile oil; chromatographic methods; 13 C NMR of sesquiterpenes. ARTIGO INTRODUÇÃOA grande maioria dos trabalhos com óleos voláteis existentes na literatura descreve a identificação de seus constituintes através da técnica de cromatografia gasosa acoplada a espectrometria de massas e/ou associada ao cálculo do índice de Kovatz. O uso desta técnica requer bancos de dados que contenham os valores dos tempos de retenção e/ou os espectros de massas para serem confrontados com os dados experimentais obtidos. Tais dados nem sempre estão disponíveis e muitas vezes sequer existem. No caso de sesquiterpenos, as análises por CG/EM não têm se mostrado eficientes uma vez que tais substâncias rearranjam-se facilmente formando fragmentos com m/z iguais, o que origina espectros que diferem apenas quanto às intensidades relativas dos picos 1 . Além disso, existe muita variação entre espectros obtidos em instrumentos diferentes.A RMN de 13 C parece ser a técnica espectroscópica mais indicada para a identificação dessas substâncias, uma vez que os sesquiterpenos constituem uma classe de substâncias naturais com uma gama muito grande de possibilidades estruturais. Um fator limitante para o uso de tal técnica é a existência de poucos dados de RMN de 13 C disponíveis na literatura, os quais possam ser empregados como modelos, especialmente quando se tratam de sesquiterpenos sem oxigenação ou mono-oxigenados, ou seja, aqueles que comumente fazem parte dos óleos voláteis. Apesar desta dificuldade, a utilização da metodologia aqui descrita tem proporcionado a identificação de vários sesquiterpenos, inclusive alguns inéditos. METODOLOGIA Separação dos constituintesPrimeiramente deve-se analisar o cromatograma obtido por CG do óleo volátil bruto*. Os valores dos tempos de retenção, obtidos em condições cromatográficas preestabelecidas, indicarão se os constituintes são predominantemente hidrocarbonetos sesquiterpênicos, sesquiterpenos mono-oxigenados, di-oxigenados e eventualmente diterpenos 2,3 . O espectro de RMN de 1 H deverá confirmar a predominância da natureza terpênica do óleo já que aril-propanóides também são componentes frequentes de óleos voláteis.A seguir o óleo volátil deve ser submetido a uma cromatografia rápida em coluna de sílica gel, utilizando-se para tal um s...