Chemical constituents from red algae Bostrychia radicans (Rhodomelaceae): new amides and phenolic compounds

This study describes the isolation and structural determination of two amides, isolated for the first time: N,4-dihydroxy-N-(2'-hydroxyethyl)-benzamide (0.019%) and N,4-dihydroxy-N-(2'-hydroxyethyl)-benzeneacetamide (0.023%). These amides, produced by the red macroalgae Bostrychia radicans, had their structures assigned by NMR spectral data and MS analyses. In addition, this chemical study led to the isolation of cholesterol, heptadecane, squalene, trans-phytol, neophytadiene, tetradecanoic and hexadecanoic acids, methyl hexadecanoate and methyl 9-octadecenoate, 4-(methoxymethyl)-phenol, 4-hydroxybenzaldehyde, methyl 4-hydroxybenzeneacetate, methyl 2-hydroxy-3-(4-hydroxyphenyl)-propanoate, hydroquinone, methyl 4-hydroxymandelate, methyl 4-hydroxybenzoate, 4-hydroxybenzeneacetic acid and (4-hydroxyphenyl)-oxo-acetaldehyde. This is the first report concerning these compounds in B. radicans, contributing by illustrating the chemical diversity within the Rhodomelaceae family.

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.

Chemical constituents of methanolic extracts of Jatropha curcas L and effects on Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)

The biological activity of seven extracts from leaves of different Jatropha curcas L (Euphorbiaceae) accessions was evaluated on Spodoptera frugiperda. Methanol extracts were incorporated into an artificial diet and offered to the larval stage of S. frugiperda. The parameters evaluated were length of larval and pupal stages, mortality of larval and total cycle stage, and weight of pupae. The extracts of the EMB accessions showed the best result for larval mortality at 60.00 and 56.67%, compared with the control, respectively. Hexane partition of the methanol extract of the leaves of PM-14 accessions allowed the identification of phytosterols, phytol and n-alkanols.

Chemical profiling of six samples of Brazilian propolis

Six samples of Brazilian propolis from Minas Gerais and Paraná states were analyzed to identify the constituents (GC/MS and HPLC/MS) and to determine their contents (HPLC and external standardization). All samples contained characteristic constituents of green propolis, but the samples from Minas Gerais had higher contents of prenylated phenylpropanoids and caffeoylquinic acids. Kaempferide and two other flavonoids were among the major constituents of the samples from Minas Gerais. Luteolin 5-O-methyl ether was detected only in samples from Paraná. Baccharis dracunculifolia was a source of resins for all samples analyzed, but the samples from Paraná had more complex plant origin.

In vitro activity of essential oils of Lippia sidoides and Lippia gracilis and their major chemical components against Thielaviopsis paradoxa, causal agent of stem bleeding in coconut palms

Essential oils of Lippia sidoides, Lippia gracilis and their main chemical components were investigated for in vitro control of Thielaviopsis paradoxa. Mycelial growth and a number of pathogen conidia were inhibited by the essential oil of L. sidoides at all concentrations tested (0.2; 0.5; 1.0; 3.0 µL mL-1). L. sidoides oil contained 42.33% thymol and 4.56% carvacrol, while L. gracilis oil contained 10% thymol and 41.7% carvacrol. Mycelial growth and conidial production of T. paradoxa were completely inhibited by thymol at a 0.3 µL m-1 concentration. The results suggest that thymol could potentially be used for controlling coconut stem bleeding.

Chemical characterization by GC-MS and phytotoxic potential of non-polar and polar fractions of seeds of Dioteryx odorata (Aubl.) Willd. from Venezuelan regions

Dipteryx odorata (Aubl.) Willd. is a tall arboreal species native to Central and Northern South America. This paper describes the chemical characterization and phytotoxic potential of polar and non-polar extracts from D. odorata seeds. Structural determinations were accomplished by chemical derivatization and analyzed by GC/MS. The chemical composition of the non-polar fraction (hexane and dichloromethane) presented fatty acids as major constituent. Medium polar and polar fractions (ethyl acetate and ethanol: water) contained carboxylic acid and high 6,7-Dyhidroxycoumarin-β-D-glucopyranoside content, not previously reported for seeds of D. odorata. Extracts showed a significant level of phytotoxic activity, correlated to the content of coumarin derivatives, predominantly in the polar fraction.

Chemical composition of volatiles from male and female specimens of Baccharis trimera collected in two distant regions of southern brazil: a comparative study using chemometrics

GC/MS/FID analyses of volatile compounds from cladodes and inflorescences from male and female specimens of Baccharis trimera (Less.) DC. collected in the states of Paraná and Santa Catarina, Brazil, showed that carquejyl acetate was the primary volatile component (38% to 73%), while carquejol and ledol were identified in lower concentrations. Data were subjected to hierarchical cluster analysis and principal component analysis, which confirmed that the chemical compositions of all samples were similar. The results presented here highlight the occurrence of the same chemotype of B. trimera in three southern states of Brazil.

Oceanografia e Química: unindo conhecimentos em prol dos oceanos e da sociedade

The marine environment is certainly one of the most complex systems to study, not only because of the challenges posed by the nature of the waters, but especially due to the interactions of physical, chemical and biological processes that control the cycles of the elements. Together with analytical chemists, oceanographers have been making a great effort in the advancement of knowledge of the distribution patterns of trace elements and processes that determine their biogeochemical cycles and influences on the climate of the planet. The international academic community is now in prime position to perform the first study on a global scale for observation of trace elements and their isotopes in the marine environment (GEOTRACES) and to evaluate the effects of major global changes associated with the influences of megacities distributed around the globe. This action can only be performed due to the development of highly sensitive detection methods and the use of clean sampling and handling techniques, together with a joint international program working toward the clear objective of expanding the frontiers of the biogeochemistry of the oceans and related topics, including climate change issues and ocean acidification associated with alterations in the carbon cycle. It is expected that the oceanographic data produced this coming decade will allow a better understanding of biogeochemical cycles, and especially the assessment of changes in trace elements and contaminants in the oceans due to anthropogenic influences, as well as its effects on ecosystems and climate. Computational models are to be constructed to simulate the conditions and processes of the modern oceans and to allow predictions. The environmental changes arising from human activity since the 18th century (also called the Anthropocene) have made the Earth System even more complex. Anthropogenic activities have altered both terrestrial and marine ecosystems, and the legacy of these impacts in the oceans include: a) pollution of the marine environment by solid waste, including plastics; b) pollution by chemical and medical (including those for veterinary use) substances such as hormones, antibiotics, legal and illegal drugs, leading to possible endocrine disruption of marine organisms; and c) ocean acidification, the collateral effect of anthropogenic emissions of CO2 into the atmosphere, irreversible in the human life time scale. Unfortunately, the anthropogenic alteration of the hydrosphere due to inputs of plastics, metal, hydrocarbons, contaminants of emerging concern and even with formerly "exotic" trace elements, such us rare earth elements is likely to accelerate in the near future. These emerging contaminants would likely soon present difficulties for studies in pristine environments. All this knowledge brings with it a great responsibility: helping to envisage viable adaptation and mitigation solutions to the problems identified. The greatest challenge faced by Brazil is currently to create a framework project to develop education, science and technology applied to oceanography and related areas. This framework would strengthen the present working groups and enhance capacity building, allowing a broader Brazilian participation in joint international actions and scientific programs. Recently, the establishment of the National Institutes of Science and Technology (INCTs) for marine science, and the creation of the National Institute of Oceanographic and Hydrological Research represent an exemplary start. However, the participation of the Brazilian academic community in the latest assaults on the frontier of chemical oceanography is extremely limited, largely due to: i. absence of physical infrastructure for the preparation and processing of field samples at ultra-trace level; ii. limited access to oceanographic cruises, due to the small number of Brazilian vessels and/or absence of "clean" laboratories on board; iii. restricted international cooperation; iv. limited analytical capacity of Brazilian institutions for the analysis of trace elements in seawater; v. high cost of ultrapure reagents associated with processing a large number of samples, and vi. lack of qualified technical staff. Advances in knowledge, analytic capabilities and the increasing availability of analytical resources available today offer favorable conditions for chemical oceanography to grow. The Brazilian academic community is maturing and willing to play a role in strengthening the marine science research programs by connecting them with educational and technological initiatives in order to preserve the oceans and to promote the development of society.

Isolation and antitrichomonal activity of the chemical constituents of the leaves of Maytenus phyllanthoides Benth. (Celastraceae)

Cyclolignan (+)-lyoniresinol (1), veratric acid (2), vanillic acid (3), lupeol, oleanolic acid, 3β-hydroxy-urs-11-en-28,13β-lactone (4), the mixture of α- and β-amyrin, trans-polyisoprene, and β-sitosterol were isolated from the leaves of Maytenus phyllanthoides. The structures of the isolated compounds were established based on spectroscopic data, mainly ¹H and 13C nuclear magnetic resonance (NMR). Compound 1, its acetate analog 1a, and compounds 2, 3, and 4 were tested against Trichomonas vaginalis. (+)-Lyoniresinol showed activity corresponding to IC50 17.57 µM. This is the first report on the occurrence of 3β-hydroxy-urs-11-en-28,13β-lactone (4) in the Celastraceous family and lyoniresinol in the Maytenus genus, and on the antitrichomonal activity of lyoniresinol.

Chemical constituents isolated from turnera subulata Sm. and electrochemical characterization of phaeophytin b

Turnera subulata Sm., known as "Chanana" or "flor-do-Guarujá" in Brazilian folklore, is a plant species belonging to the subfamily Turneroideae of family Passifloraceae, which is used for various medicinal purposes in Brazil. The phytochemical study conducted here led to the isolation and identification of ten compounds present in T. subulata: two mixtures of steroids, sitosterol and stigmasterol (nonglycosylated and glycosylated); a mixture of flavonoids, 5,7,4′-trihidroxiflavona-8-C-α-glucopyranoside and 5,7,3′,4′-tetrahidroxiflavona-8-C-α-glucopyranosidel; and four phaeophytins, phaeophytin purpurin-18-phytyl ester, a rare natural product, phaeophytin a , 13²-hydroxy-(13²-S)-phaeophytin a , and phaeophytin b Phaeophytin b exhibited electrochemical activity similar to that of phthalocyanines.

Inertization of small-scale chemical wastes using iron phosphate glass

The viability of small-scale heavy-metal waste immobilization into iron phosphate glasses was investigated. Several waste forms containing different amounts of heavy-ion wastes were evaluated (5%, 10%, 15%, 20%, 26%, 33%, 40% and 50% by mass) and their X-ray diffraction patterns revealed that no crystallization occurred in glasses with waste concentrations up to 26%. The dissolution rates for all of the reported glass compositions (ca. 10-8 g cm-2 min-1) are similar to those reported for the materials most commonly used for waste vitrification. Iron phosphate glasses thus proved to be very useful for the immobilization of heavy-metal wastes, exhibiting good contention and chemical durability comparable to that of borosilicate glasses.

Application of fourier transform infrared spectroscopy, chemical and chemometrics analyses to the characterization of agro-industrial waste

Agroindustrial waste in general presents significant levels of nutrients and organic matter and has therefore been frequently put to agricultural use. In this context, the objective of this study was to determine the chemical composition, nitrogen, phosphorus, potassium, calcium, magnesium and carbon content, as well as the qualitative characteristics through Fourier transform infrared spectroscopy of four samples of poultry litter and one sample of cattle manure, from the southwestern region of Paraná, Brazil. Results revealed that, in general, the poultry litter presented higher amount of nutrients and carbon than the cattle manure. The infrared spectra allowed identification of the functional groups present and the differences in degree of sample humification. The statistical treatment confirmed the quantitative and qualitative differences revealed.

Physico-chemical properties of meso-tetrakis(p-methoxyphenyl)porphyrin (TMPP) incorporated into pluronicTM p-123 and f-127 polymeric micelles

The physicochemical properties (solubilization, structural organization and stability) of meso-tetrakis(p-methoxyphenyl)porphyrin (TMPP), a promising photosensitizer for photodynamic therapy, solubilized in polymeric micelles of tri-block copolymers PluronicTM P-123 and F-127, were studied. The formulations obtained by the solid dispersion method led to monomerization of TMPP in these copolymers. Solubility studies showed that P-123 solubilizes double the photosensitizer than F-127. The self-aggregation phenomenon was affected by the [TMPP]/[poloxamer] ratio and medium temperature. The decrease in the temperature of these systems promoted the formation of different kinds of TMPP aggregates intrinsically connected with the structural changes occurring in the micelles.

CHEMICAL STUDY OF Hortia superba (Rutaceae) AND INVESTIGATION OF THE ANTIMYCOBACTERIAL ACTIVITY OF CRUDE EXTRACTS AND CONSTITUENTS ISOLATED FROM Hortia SPECIES

In this paper, the chemical study of Hortia superba and antimycobacterial potential of Hortia species were investigated. Crude extracts and limonoids, alkaloids, dihydrocinnamic acid derivatives and coumarins isolated from Hortia superba, Hortia oreadica and Hortia brasiliana were evaluated against Mycobacterium tuberculosis H37Rv, Mycobacterium kansasii and Mycobacterium avium. The results obtained demonstrated an inhibitory effect of the dichloromethane extract of leaves of H. oreadica (MIC 31.25 µg mL-1), indolequinazoline (15.62 µg mL-1) and furoquinoline (31.25 µg mL-1) alkaloids, and dihydrocinnamic acid derivatives (62.50 µg mL-1), on the growth of M. tuberculosis. These results are promising in relation to the search for biologically active natural products and could be useful in the development of effective new drugs against mycobacteria.

Salacia crassifolia (Celastraceae): CHEMICAL CONSTITUENTS AND ANTIMICROBIAL ACTIVITY

The phytochemical study of hexane extract from leaves of Salacia crassifolia resulted in the isolation of 3β-palmitoxy-urs-12-ene, 3-oxofriedelane, 3β-hydroxyfriedelane, 3-oxo-28-hydroxyfriedelane, 3-oxo-29-hydroxyfriedelane, 28,29-dihydroxyfriedelan-3-one, 3,4-seco-friedelan-3-oic acid, 3β-hydroxy-olean-9(11):12-diene and the mixture of α-amirin and β-amirin. β-sitosterol, the polymer gutta-percha, squalene and eicosanoic acid were also isolated. The chemical structures of these constituents were established by IR, 1H and 13C NMR spectral data. Crude extracts and the triterpenes were tested against Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis and no activity was observed under the in vitro assay conditions. The hexane, chloroform, ethyl acetate and ethanol crude extracts, and the constituent 3,4-seco-friedelan-3-oic acid and 28,29-dihydroxyfriedelan-3-one showed in vitro antimicrobial activity against Salmonella typhimurium, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Streptococcus sanguinis and Candida albicans.