Biomimetic chemical reactions with natural products using metalloporphyrins and salen complexes as catalysts: a brief review.

The cytochrome P450 is a superfamily of hemoproteins mainly present in the liver and are versatile biocatalysts. They participate in the primary metabolism and biosynthesis of various secondary metabolites. Chemical catalysts are utilized to replicate the activities of enzymes. Metalloporphyrins and Salen complexes can contribute to the products' characterization and elucidate biotransformation processes, which are investigated during pre-clinical trials. These catalysts also help discover biologically active compounds and get better yields of products of industrial interest. This review aims to investigate which natural product classes are being investigated by biomimetic chemical models and the functionalities applied in the use of these catalysts. A limited number of studies were observed, with terpenes and alkaloids being the most investigated natural product classes. The research also revealed that Metalloporphyrins are still the most popular in the studies, and the identity and yield of the products obtained depend on the reaction system conditions.

Wastewater surveillance to assess cocaine and methylenedioxymethamphetamine use trends during a major music festival in Brazil.

Wastewater-based epidemiology was applied in northeastern Brazil during a dance festival, revealing that cocaine consumption doubled during the event days. The daily drug loads were 0.95 ± 0.03 to 11.4 ± 0.4 g/day for BE, 1.8 ± 0.4 to 7.6 ± 0.3 g/day for COC, 0.04 ± 0.02 to 0.19 ± 0.02 g/day for COE, and 0.08 ± 0.02 to 0.80 ± 0.02 g/day for MDMA.

This study employed the wastewater­based epidemiology (WBE) strategy to investigate cocaine (COC) and ecstasy (MDMA) usage during Carnatal festival in Rio Grande do Norte, Brazil. Wastewater samples were collected over the four festival days (December 12­15, 2019), as well as during corresponding days before and after the event. The samples underwent filtration, acidification, solid­phase extraction (SPE) for pre­concentration, and analysis using ultra­high­performance liquid chromatography­tandem mass spectrometry (UHPLC­MS/MS) with calibration using deuterated internal standards. The measured concentration ranges in the wastewater samples were as follows: benzoylecgonine (BE, a metabolite of COC use) ranged from 760 ± 30 to 8914 ± 252 ng/L, COC (non­metabolized or directly discharged) ranged from 1182 ± 25 to 6,760 ± 95 ng/L, cocaethylene (COE, a metabolite of alcohol­COC use) ranged from 21 ± 10 to 161 ± 10 ng/L, and MDMA (ecstasy) ranged from 18 ± 5 to 613 ± 15 ng/L. Daily wastewater loads were estimated as 0.81 ± 0.03 to 11.69 ± 0.33 g/day for BE, 1.42 ± 0.03 to 8.06 ± 0.11 g/day for COC, 0.02 ± 0.01 to 0.21 ± 0.01 g/day for COE, and 0.02 ± 0.01 to 0.80 ± 0.02 g/day for MDMA. Notably, COE and MDMA were only detected above the quantification limit during the festival days. The data enable estimating that COC consumption doubled during the event days. The COC/BE ratio indicated likely drug disposals on the event's last day and the subsequent week. The study's findings shed light on illicit substance consumption, assisting in public health programs and combating drug trafficking efforts.

Lacticaseibacillus casei decrease long-chain fatty acids and most substances in an experimental model of intestinal mucositis.

PURPOSE: To evaluate the long-chain fatty acid and major compounds levels in the feces after prophylactic oral use of Lacticaseibacillus casei in an experimental model of intestinal mucositis. METHODS: Fifteen Swiss mice were randomly divided into three groups (n=5/group): The negative or positive control groups (n = 5) received saline orally for 18 days and an the intraperitoneal (i.p.) of saline or 5 Fluorouracil (450 mg/kg) in 15th day, respectability. L. casei group received oral concentration of L. casei (1x109 CFU/mL) for 18 days, the i.p. injection of 5-fluorouracil (450 mg/kg) in 15th days. Tissue samples from colon and each small intestine segment were collected for histopathological analysis. Stool samples were collected. Fecal composition of long-chain fatty acids and sterols were analysed by gas chromatography-mass spectrometry on the 15th and the 18th day. RESULTS: The mucosa layer of all small intestine segments of animals from L. casei showed well preserved epithelium and glands, without necrosis signs, but Goblet cells number decreased. Several long-chain fatty acids and sterols have been identified before and after in the groups. L. casei administration after 5-FU treatment reduced concentrations of linoleic acid (18:2) (p < 0.001) and oleic acid (18:1) (p < 0.001) in feces. CONCLUSIONS: L. casei prevented the mucosal damage associated with 5-FU-induced intestinal mucositis reduced long-chain fatty acid levels in the feces.

Challenges encountered by natural repellents: Since obtaining until the final product.

Vector-borne diseases, particularly the arboviruses dengue, Zika, chikungunya, and yellow fever caused by the Aedes aegypti mosquito, have been driving the use of repellents worldwide. The most representative synthetic repellent, DEET stands out as the market's oldest and most efficient repellent. It is considered a reference standard but presents considerable toxicity, not recommended for children up to 6 months old and pregnant women. For this reason, alternatives have been sought, and natural repellents derived mainly from essential oils have been studied, highlighting the essential oils of lemon (Corymbia citriodora), citronella (Cympobogon sp.), Andiroba (Carapa guianensis). However, the development and commercialization of products containing natural repellents are significantly lower when compared to DEET and other synthetic repellents. In order to understand the reasons, aspects related to safety, mechanism of action, efficacy as well development and complexity of the products were evaluated. It is concluded that, as for safety, there is lacking information in the literature regarding the effects on non-target organisms and robust toxicity data. The mechanism of action is based on theories, with less information on the exact mode of action, molecular targets, and interaction with the olfactory and taste receptors of insects. Despite being a current trend to search for actives from natural sources highly present in essential oils, however they reduced action time because due to rapid evaporation after application to the skin, thus requiring repellent vehicles. The development and complexity related to these products bring challenging aspects, beginning on the plant cultivation and extraction processes to produce essential oils with a more homogeneous chemical composition towards the formulation stabilization processes due to fast evaporation and short action time, with the use of pharmaceutical technology such as encapsulation techniques.

Lacticaseibacillus casei decrease long-chain fatty acids and most substances in an experimental model of intestinal mucositis

Purpose: To evaluate the long-chain fatty acid and major compounds levels in the feces after prophylactic oral use of Lacticaseibacillus casei in an experimental model of intestinal mucositis. Methods: Fifteen Swiss mice were randomly divided into three groups (n=5/group): The negative or positive control groups (n = 5) received saline orally for 18 days and an the intraperitoneal (i.p.) of saline or 5 Fluorouracil (450 mg/kg) in 15th day, respectability. L. casei group received oral concentration of L. casei (1x109 CFU/mL) for 18 days, the i.p. injection of 5-fluorouracil (450 mg/kg) in 15th days. Tissue samples from colon and each small intestine segment were collected for histopathological analysis. Stool samples were collected. Fecal composition of long-chain fatty acids and sterols were analysed by gas chromatography-mass spectrometry on the 15th and the 18th day. Results: The mucosa layer of all small intestine segments of animals from L. casei showed well preserved epithelium and glands, without necrosis signs, but Goblet cells number decreased. Several long-chain fatty acids and sterols have been identified before and after in the groups. L. casei administration after 5-FU treatment reduced concentrations of linoleic acid (18:2) (p < 0.001) and oleic acid (18:1) (p < 0.001) in feces. Conclusions: L. casei prevented the mucosal damage associated with 5-FU-induced intestinal mucositis reduced long-chain fatty acid levels in the feces.

Non-target molecular network and putative genes of flavonoid biosynthesis in Erythrina velutina Willd., a Brazilian semiarid native woody plant.

Erythrina velutina is a Brazilian native tree of the Caatinga (a unique semiarid biome). It is widely used in traditional medicine showing anti-inflammatory and central nervous system modulating activities. The species is a rich source of specialized metabolites, mostly alkaloids and flavonoids. To date, genomic information, biosynthesis, and regulation of flavonoids remain unknown in this woody plant. As part of a larger ongoing research goal to better understand specialized metabolism in plants inhabiting the harsh conditions of the Caatinga, the present study focused on this important class of bioactive phenolics. Leaves and seeds of plants growing in their natural habitat had their metabolic and proteomic profiles analyzed and integrated with transcriptome data. As a result, 96 metabolites (including 43 flavonoids) were annotated. Transcripts of the flavonoid pathway totaled 27, of which EvCHI, EvCHR, EvCHS, EvCYP75A and EvCYP75B1 were identified as putative main targets for modulating the accumulation of these metabolites. The highest correspondence of mRNA vs. protein was observed in the differentially expressed transcripts. In addition, 394 candidate transcripts encoding for transcription factors distributed among the bHLH, ERF, and MYB families were annotated. Based on interaction network analyses, several putative genes of the flavonoid pathway and transcription factors were related, particularly TFs of the MYB family. Expression patterns of transcripts involved in flavonoid biosynthesis and those involved in responses to biotic and abiotic stresses were discussed in detail. Overall, these findings provide a base for the understanding of molecular and metabolic responses in this medicinally important species. Moreover, the identification of key regulatory targets for future studies aiming at bioactive metabolite production will be facilitated.

The First Optimization Process from Cultivation to Flavonoid-Rich Extract from Moringa oleifera Lam. Leaves in Brazil.

Flavonoids are significant antioxidant and anti-inflammatory agents and have multiple potential health applications. Moringa oleifera is globally recognized for its nutritional and pharmacological properties, correlated to the high flavonoid content in its leaves. However, the bioactive compounds found in plants may vary according to the cultivation, origin, season, and extraction process used, making it difficult to extract reliable raw material. Hence, this study aimed to standardize the best cultivation and harvest season in Brazil and the best extraction process conditions to obtain a flavonoid-rich extract from M. oleifera as a final product. Firstly, ultrasound-assisted extraction (UAE) was optimized to reach the highest flavonoid content by three-level factorial planning and response surface methodology (RSM). The optimal cultivation condition was mineral soil fertilizer in the drought season, and the optimized extraction was with 80% ethanol and 13.4 min of extraction time. The flavonoid-rich extract was safe and significantly decreased reactive oxygen species (ROS) and nitric oxide (NO) in LPS-treated RAW 264.7 cells. Lastly, the major flavonoids characterized by HPLC-ESI-QTRAP-MS/MS were compounds derived from apigenin, quercetin, and kaempferol glycosides. The results confirmed that it was possible to standardize the flavonoid-rich extract leading to a standardized and reliable raw material extracted from M. oleifera leaves.

Purification of chitosanases produced by Bacillus toyonensis CCT 7899 and functional oligosaccharides production.

Chitooligosaccharides (COS) have a great potential to be used by pharmaceutical industry due to their many biological activities. The use of enzymes to produce them is very advantageous, however it still faces many challenges, such as discovering new strains capable to produce enzymes that are able to generate bioactive oligosaccharides. In the present study a purification protein protocol was performed to purify chitosanases produced by Bacillus toyonensis CCT 7899 for further chitosan hydrolysis. The produced chitooligosaccharides were characterized by mass spectroscopy (MS) and their antiedematogenic effect was investigated through carrageenan-induced paw edema model. The animals were treated previously to inflammation by intragastric route with COS at 30, 300 and 600 mg/kg. The purification protocol showed a good performance for the chitosanases purification using 0.20 M NaCl solution to elute it, with a 9.54-fold purification factor. The treatment with COS promoted a decrease of paw edema at all evaluated times and the AUC0-4h, proving that COS produced showed activity in acute inflammation like commercial anti-inflammatory Dexamethasone (corticosteroid). Therefore, the strategy used to purification was successfully applied and it was possible to generate bioactive oligosaccharides with potential pharmacological use.

Antimicrobial Activity of Chitosan Oligosaccharides with Special Attention to Antiparasitic Potential.

The global rise of infectious disease outbreaks and the progression of microbial resistance reinforce the importance of researching new biomolecules. Obtained from the hydrolysis of chitosan, chitooligosaccharides (COSs) have demonstrated several biological properties, including antimicrobial, and greater advantage over chitosan due to their higher solubility and lower viscosity. Despite the evidence of the biotechnological potential of COSs, their effects on trypanosomatids are still scarce. The objectives of this study were the enzymatic production, characterization, and in vitro evaluation of the cytotoxic, antibacterial, antifungal, and antiparasitic effects of COSs. NMR and mass spectrometry analyses indicated the presence of a mixture with 81% deacetylated COS and acetylated hexamers. COSs demonstrated no evidence of cytotoxicity upon 2 mg/mL. In addition, COSs showed interesting activity against bacteria and yeasts and a time-dependent parasitic inhibition. Scanning electron microscopy images indicated a parasite aggregation ability of COSs. Thus, the broad biological effect of COSs makes them a promising molecule for the biomedical industry.

Erythrina velutina Willd. alkaloids: Piecing biosynthesis together from transcriptome analysis and metabolite profiling of seeds and leaves.

Introduction: Natural products of pharmaceutical interest often do not reach the drug market due to the associated low yields and difficult extraction. Knowledge of biosynthetic pathways is a key element in the development of biotechnological strategies for plant specialized metabolite production. Erythrina species are mainly used as central nervous system depressants in folk medicine and are important sources of bioactive tetracyclic benzylisoquinoline alkaloids (BIAs), which can act on several pathology-related biological targets. Objectives: In this sense, in an unprecedented approach used with a non-model Fabaceae species grown in its unique arid natural habitat, a combined transcriptome and metabolome analyses (seeds and leaves) is presented. Methods: The Next Generation Sequencing-based transcriptome (de novo RNA sequencing) was carried out in a NextSeq 500 platform. Regarding metabolite profiling, the High-resolution Liquid Chromatography was coupled to DAD and a micrOTOF-QII mass spectrometer by using electrospray ionization (ESI) and Time of Flight (TOF) analyzer. The tandem MS/MS data were processed and analyzed through Molecular Networking approach. Results: This detailed macro and micromolecular approach applied to seeds and leaves of E. velutina revealed 42 alkaloids, several of them unique. Based on the combined evidence, 24 gene candidates were put together in a putative pathway leading to the singular alkaloid diversity of this species. Conclusion: Overall, these results could contribute by indicating potential biotechnological targets for modulation of erythrina alkaloids biosynthesis as well as improve molecular databases with omic data from a non-model medicinal plant, and reveal an interesting chemical diversity of Erythrina BIA harvested in Caatinga.

Erythroxylum pungens Tropane Alkaloids: GC-MS Analysis and the Bioactive Potential of 3-(2-methylbutyryloxy)tropan-6,7-diol in Zebrafish (Danio rerio).

Tropane alkaloids are specialized plant metabolites mostly found in the Erythroxylaceae and Solanaceae families. Although tropane alkaloids have a high degree of structural similarity because of the tropane ring, their pharmacological actions are quite distinct. Brazil is one of the main hotspots of Erythroxylum spp. diversity with 123 species (almost 66% of the species catalogued in tropical America). Erythroxylum pungens occurs in the Caatinga, a promising biome that provides bioactive compounds, including tropane alkaloids. As part of our efforts to investigate this species, 15 alkaloids in specimens harvested under different environmental conditions are presented herein. The occurrence of 3-(2-methylbutyryloxy)tropan-6,7-diol in the stem bark of plants growing in their natural habitat, greenhouse controlled conditions, and after a period of water restriction, suggests that it is a potential chemical marker for the species. This alkaloid was evaluated for several parameters in zebrafish (Danio rerio) as a model organism. Regarding toxicity, teratogenic effects were observed at 19.5 µM and the lethal dose for embryos was 18.4 µM. No mortality was observed in adults, but a behavioral screen showed psychostimulatory action at 116.7 µM. Overall, the alkaloid was able to cause zebrafish behavioral changes, prompting further investigation of its potential as a new molecule in the treatment of depression-like symptoms. In silico, targets involved in antidepressant pathways were identified by docking.

In Vivo Antidepressant Effect of Passiflora edulis f. flavicarpa into Cationic Nanoparticles: Improving Bioactivity and Safety.

A variety of neuroactive flavonoids can be found in the species of the Passiflora genus; however, their difficulty in crossing the blood-brain barrier limits their in vivo neuropharmacological activity. In this study, cationic nanoparticles were developed as a novel nanocarrier for improving the antidepressant activity of Passiflora edulis f. flavicarpa leaf extract. Formulations obtained using Eudragit E PO polymethylmethacrylate copolymer, as polymeric matrix had their physicochemical properties investigated. The analytical content of the flavonoids vicenin-2, orientin, isoorientin, vitexin, and isovitexin was determined in the plant extract. Small-sized and spherical nanoparticles loaded with Passiflora edulis f. flavicarpa were obtained with positive zeta potential and high encapsulation efficiency. In addition, the nanosystems were shown to be stable for at least 6 months. The antidepressant activity of P. edulis extract (50 and 100 mg/kg) as well as the extract-loaded nanoparticles (5 mg/kg) were investigated in mice using the forced swimming test, where the latter increased the potency of the former by 10-fold. In addition, histopathological and biochemical analysis confirmed the biocompatibility of the extract-loaded nanoparticles. This study demonstrated that the Eudragit cationic nanoparticles were able to improve the antidepressant activity of P. edulis in the central nervous system of mice.

Isolation, spectral characterization, molecular docking, and cytotoxic activity of alkaloids from Erythroxylum pungens O. E. Shulz.

Stem bark, root bark, and leaf extracts of Erythroxylum pungens were subjected to phytochemical analysis. N,N-dimethyltryptamine (DMT) was isolated and characterized from E. pungens roots. This unprecedented result is remarkable since no indole alkaloid has been previously reported from Erythroxylaceae so far. Eleven known tropane alkaloids were identified by their mass spectra and 3-(2-methylbutyryloxy)tropan-6,7-diol as well as 3-(2-methylbutyryloxy)nortropan-6,7-diol were isolated and characterized based on mass spectrometry, 1H, 13C, COSY, and NOESY NMR analysis. The complete NMR data are reported for the first time. Inverse Structure-based and Ligand-Based virtual screening were carried out to identify possible targets for 3-(2-methylbutyryloxy)tropan-6,7-diol. The level of cytotoxicity of this tropane alkaloid aliphatic ester was discrete with potencies on the order of 0.3-1.0 mg/mL and better results against HeLa (50% cell viability reduction). Otherwise, atropine (0.3 mg/mL), a Solanaceae tropane alkaloid, and DMT (0.5 mg/mL) from E. pungens roots impaired at 50% the cell viability against HeLa, SiHa, PC3, and 786-0. This study stimulates scientific investigation of the impact of edaphoclimatic features in a semi-arid environment on tropane alkaloid biosynthesis.

Gastroprotective and Antioxidant Activity of Kalanchoe brasiliensis and Kalanchoe pinnata Leaf Juices against Indomethacin and Ethanol-Induced Gastric Lesions in Rats.

Kalanchoe brasiliensis and Kalanchoe pinnata are used interchangeably in traditional medicine for treating peptic ulcers and inflammatory problems. In this context, this study aims to characterize the chemical constituents and evaluate the gastroprotective activity of the leaf juices of the two species in acute gastric lesions models. Thin Layer Chromatography (TLC) and Ultra High Performance Liquid Chromatography coupled to Mass Spectrometer (UHPLC-MS) were performed for chemical characterization. Wistar rats were pre-treated orally with leaf juices (125, 250 and 500 mg/kg) or ranitidine (50 mg/kg). The peaks observed in the chromatogram of K. brasiliensis showed similar mass spectra to flavonoid glycosides derived from patuletin and eupafolin, while K. pinnata showed mass spectra similar to compounds derived from quercetin, patuletin, eupafolin and kaempferol. K. brasiliensis at all doses and K. pinnata at doses of 250 mg/kg and 500 mg/kg significantly reduced the lesions in the ethanol induction model. In the indomethacin induction model, both species showed significant results at doses of 250 and 500 mg/kg. Also, the pre-treatment with leaf juices increased the antioxidant defense system, glutathione (GSH), whereas malondialdehyde (MDA), myeloperoxidase (MPO), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) levels were significantly decreased. Treatment with leaf juices led to the upregulation of zone occludes-1 (ZO-1) and the downregulation of inducible nitric oxide synthase (iNOS) and factor nuclear-κβ transcription (NF-κB-p65), while also showing a cytoprotective effect and maintaining mucus production. These findings show that the leaf juices of the two species showed gastroprotective effects on ethanol and gastric indomethacin injury which were a consequence of gastric inflammation suppression, antioxidant activity and the maintenance of cytoprotective defenses and mucosal structure architecture.

Structure and in vitro activities of a Copper II-chelating anionic peptide from the venom of the scorpion Tityus stigmurus.

Anionic Peptides are molecules rich in aspartic acid (Asp) and/or glutamic acid (Glu) residues in the primary structure. This work presents, for the first time, structural characterization and biological activity assays of an anionic peptide from the venom of the scorpion Tityus stigmurus, named TanP. The three-dimensional structure of TanP was obtained by computational modeling and refined by molecular dynamic (MD) simulations. Furthermore, we have performed circular dichroism (CD) analysis to predict TanP secondary structure, and UV-vis spectroscopy to evaluate its chelating activity. CD indicated predominance of random coil conformation in aqueous medium, as well as changes in structure depending on pH and temperature. TanP has chelating activity on copper ions, which modified the peptide's secondary structure. These results were corroborated by MD data. The molar ratio of binding (TanP:copper) depends on the concentration of peptide: at lower TanP concentration, the molar ratio was 1:5 (TanP:Cu2+), whereas in concentrated TanP solution, the molar ratio was 1:3 (TanP:Cu2+). TanP was not cytotoxic to non-neoplastic or cancer cell lines, and showed an ability to inhibit the in vitro release of nitric oxide by LPS-stimulated macrophages. Altogether, the results suggest TanP is a promising peptide for therapeutic application as a chelating agent.

Structure and in vitro activities of a Copper II-chelating anionic peptide from the venom of the scorpion Tityus stigmurus

An ionic Peptides are molecules rich in aspartic acid (Asp) and/or glutamic acid (Glu) residues in the primary structure. This work presents, for the first time, structural characterization and biological activity assays of an anionic peptide from the venom of the scorpion Tityus stigmurus, named TanP. The three-dimensional structure of TanP was obtained by computational modeling and refined by molecular dynamic (MD) simulations. Furthermore, we have performed circular dichroism (CD) analysis to predict TanP secondary structure, and UV-vis spectroscopy to evaluate its chelating activity. CD indicated predominance of random coil conformation in aqueous medium, as well as changes in structure depending on pH and temperature. TanP has chelating activity on copper ions, which modified the peptide's secondary structure. These results were corroborated by MD data. The molar ratio of binding (TanP: copper) depends on the concentration of peptide: at lower TanP concentration, the molar ratio was 1:5 (TanP: Cu2+), whereas in concentrated TanP solution, the molar ratio was 1:3 (TanP: Cu2+). TanP was not cytotoxic to non-neoplastic or cancer cell lines, and showed an ability to inhibit the in vitro release of nitric oxide by LPS-stimulated macrophages. Altogether, the results suggest TanP is a promising peptide for therapeutic application as a chelating agent.

In vitro metabolism of the lignan (-)-grandisin, an anticancer drug candidate, by human liver microsomes.

(-)-grandisin is a tetrahydrofuran lignan that displays important biological properties, such as trypanocidal, anti-inflammatory, cytotoxic, and antitumor activities, suggesting its utility as a potential drug candidate. One important step in drug development is metabolic characterization and metabolite identification. To perform a biotransformation study of (-)-grandisin and to determine its kinetic properties in humans, a high performance liquid chromatography (HPLC) method was developed and validated. After HPLC method validation, the kinetic properties of (-)-grandisin were determined. (-)-grandisin metabolism obeyed Michaelis-Menten kinetics. The maximal reaction rate (Vmax ) was 3.96 ± 0.18 µmol/mg protein/h, and the Michaelis-Menten constant (Km ) was 8.23 ± 0.99 µM. In addition, the structures of the metabolites derived from (-)-grandisin were characterized via gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) analysis. Four metabolites, 4-O-demethylgrandisin, 3-O-demethylgrandisin, 4,4'-di-O-demethylgrandisin, and a metabolite that may correspond to either 3,4-di-O-demethylgrandisin or 3,5-di-O-demethylgrandisin, were detected. CYP2C9 isoform was the main responsible for the formation of the metabolites. These metabolites have not been previously described, demonstrating the necessity of assessing (-)-grandisin metabolism using human-derived materials.

In vitro metabolism study of the promising anticancer agent the lignan (-)-grandisin.

The lignan (-)-grandisin has shown important pharmacological activities, such as citotoxicity and antiangiogenic, antibacterial and trypanocidal activities. So, it has been considered as a potential drug candidate. In the early drug development process, drug metabolism is one of the main parameters that should be evaluated; therefore, the biotransformation of this lignan by rat liver microsomes was investigated for the first time. In order to perform the biotransformation study and to determine the kinetic parameters, a simple, sensitive and selective HPLC method was developed and fully validated. After method validation, the biotransformation study was accomplished and the kinetic parameters were determined. The biotransformation study obeyed the Michaelis-Menten kinetics. The V(max) and K(m) were 1.46 ± 0.034 µmol/mg protein/h and 8.99 ± 0.488 µM, respectively. In addition, the formation of dihydro-grandisin, characterized by GC-MS, by mammalian systems indicated the involvement of a CYP450 enzyme type.

Concentration of Inorganic Elements Content in Benthic Seaweeds of Fernando de Noronha Archipelago by Synchrotron Radiation Total Reflection X-Ray Fluorescence Analysis (SRTXRF).

SRTXRF WAS USED TO DETERMINE AS, BA, BR, CA, CO, CR, CS, CU, DY, FE, K, MN, MO, NI, PB, RB, SR, TI, V, AND ZN IN ELEVEN SEAWEED SPECIES COMMONLY FOUND IN FERNANDO DE NORONHA: Caulerpa verticillata (J. Agardh) (Chlorophyta), Asparagopsis taxiformis (Delile), Dictyurus occidentalis (J. Agardh), Galaxaura rugosa (J. Ellis & Solander) J. V. Lamouroux, G. obtusata (J. Ellis & Solander) J. V. Lamouroux, G. marginata (J. Ellis & Solander) J. V. Lamouroux (Rhodophyta), Dictyota cervicornis (Kützing), Dictyopteris justii (J. V. Lamouroux), Dictyopteris plagiogramma (Montagne) Vickers, Padina gymnospora (Kützing) Sonder, and a Sargassum sp. (Phaeophyta). Data obtained were compared to those from the analysis of other parts of the world seaweeds using different analytical techniques and were found to be in general agreement in terms of major and minor elemental components. Results provide baseline information about the absorption and accumulation of these elements by macroalgae in the area.

Apolar compounds in seaweeds from fernando de noronha archipelago (northeastern coast of Brazil).

Hyphenated techniques of gas chromatography coupled to mass spectrometer were used to determine fatty acids in eleven species of seaweeds from Fernando de Noronha archipelago. The main compounds detected in all studied species were the alcohol phytol and the fatty acids 14 : 0; 15 : 0; 16 : 0; 18 : 0; 18 : 1 n(9); 18 : 2 Δ(9,12); 20 : 4; 20 : 5. These fatty acids are commonly found in seaweeds present in warm regions. Thus, we found no specificity in the presence of a particular set of fatty acids and the studied species indicating that they are not useful as taxonomic indicators. However, they could be used in a comparative study with algae found in polluted area because many of the studied seaweeds are widespread and Fernando de Noronha has low human influence.