Candesartan exhibits low intrinsic permeation capacity and affects buccal tissue viability and integrity: An ex vivo study in porcine buccal mucosa.

Candesartan is a nonpeptide angiotensin II receptor blocker that selectively binds to angiotensin II receptor subtype 1. It is administered orally in its ester form (candesartan cilexetil). However, its poor aqueous solubility results in its low bioavailability; therefore, other routes of administration must be explored. The buccal mucosa has been extensively studied as an alternative route for drug delivery as it improves the bioavailability of drugs administered via the peroral route. Porcine buccal mucosa has been widely used as an ex vivo model to study the permeability of various diffusants; however, studies on candesartan are limited. This study aimed to evaluate the ex vivo permeation profile of candesartan and its effects on the viability and integrity of porcine buccal mucosa. Initially, we evaluated the viability, integrity, and barrier function of the buccal tissue before performing permeability tests using freshly excised tissues or tissues after 12 h of resection. Here, three indicators were used: caffeine, ß-estradiol, and FD-20 penetration; mucosal metabolic activity, as determined using MTT reduction assay; and haematoxylin and eosin staining. Our results indicated that the porcine buccal mucosa preserved its viability, integrity, and barrier function before the permeation assay, allowing the passage of molecules with a molecular mass of less than 20 kDa, such as caffeine, but not ß-estradiol and FD-20. Furthermore, we analyzed the intrinsic capacity of candesartan to diffuse through the fresh porcine buccal mucosa under two pH conditions. The concentration of candesartan in the receptor chamber of Franz diffusion cell was quantified using ultra-high liquid chromatography. In the permeation assay, candesartan exhibited a low intrinsic permeation capacity that impacted the buccal tissue viability and integrity, suggesting that using the buccal mucosa as an alternative route of administration requires developing a pharmaceutical formulation that reduces the adverse effects on mucosa and increasing the buccal permeability of candesartan.

Data Fusion-based Discovery (DAFdiscovery) pipeline to aid compound annotation and bioactive compound discovery across diverse spectral data.

INTRODUCTION: Data Fusion-based Discovery (DAFdiscovery) is a pipeline designed to help users combine mass spectrometry (MS), nuclear magnetic resonance (NMR), and bioactivity data in a notebook-based application to accelerate annotation and discovery of bioactive compounds. It applies Statistical Total Correlation Spectroscopy (STOCSY) and Statistical HeteroSpectroscopy (SHY) calculation in their data using an easy-to-follow Jupyter Notebook. METHOD: Different case studies are presented for benchmarking, and the resultant outputs are shown to aid natural products identification and discovery. The goal is to encourage users to acquire MS and NMR data from their samples (in replicated samples and fractions when available) and to explore their variance to highlight MS features, NMR peaks, and bioactivity that might be correlated to accelerated bioactive compound discovery or for annotation-identification studies. RESULTS: Different applications were demonstrated using data from different research groups, and it was shown that DAFdiscovery reproduced their findings using a more straightforward method. CONCLUSION: DAFdiscovery has proven to be a simple-to-use method for different situations where data from different sources are required to be analyzed together.

The state of the art of marine natural products in Colombia / El estado del arte de los productos naturales marinos en Colombia / O estado da arte dos produtos naturais marinhos na Colômbia

Abstract Marine Natural Products (MNPs) isolated from samples collected in Colombia have been an object of study since the early 1980's; however, this information is neither integrated nor compiled. This systematic review describes the articles published in scientific journals up to December 2019. 173 papers met the inclusion criteria of focusing on MNPs obtained from specimens collected from Colombian seas; all original papers written in English, Portuguese or Spanish. The selected papers were mostly authored by researchers from Colombian groups, with low interaction amongst themselves. 99.4% of the papers studied samples collected from the Caribbean Sea; 183 species were studied, mainly sponges and octocorals. In this study, 1,690 compounds (238 new ones) were reviewed, mainly diterpenes and sterol derivatives. Of the selected papers, 76.8% measured various biological activities, including antibiotic (34%) and anticancer (30%). These papers were published in 51 journals (74.6% were international). In conclusion, scientific work on natural marine products of Colombian origin has incremented over time. The most relevant opportunities to address and fill existing gaps comprise: exploring Pacific Ocean organisms and several of the misrepresented taxa; promoting strong interactions amongst the MNPs research groups, and accordingly with other areas of knowledge; and having the productive sector participate in MNPs research.

Resumen Los productos naturales marinos (PNM) aislados de muestras recolectadas en Colombia han sido estudiados desde principios de los años 1980, mas esta información no está integrada, ni recopilada. Esta revisión sistemática describe los artículos publicados hasta diciembre de 2019. 173 artículos cumplieron los criterios de inclusión de enfoque en PNM obtenidos de especímenes recolectados en mares colombianos; trabajos originales escritos en inglés, portugués o español. La mayoría de los artículos fueron escritos por investigadores de grupos colombianos, con poca interacción entre ellos. El 99,4% de los artículos estudiaban muestras recolectadas del mar Caribe. Se estudiaron 183 especies, especialmente esponjas y octocorales. Se identificaron 1690 compuestos (238 nuevos), principalmente diterpenos y derivados de esteroles. En el 76,8% de los artículos se midió alguna actividad biológica, principalmente antibiótica (34%) y anticancerígena (30%). Los artículos se publicaron en 51 revistas (74,6% internacionales). En conclusión, la investigación sobre los PNM de origen colombiano ha crecido con el tiempo. Algunas oportunidades para abordar las lagunas encontradas comprenden: explorar los organismos del océano Pacífico y los taxa poco estudiados; promover interacciones entre los grupos de investigación de los PNM y de otras áreas del conocimiento; e involucrar al sector productivo en la investigación de los PMN.

Resumo Os Produtos Naturais Marinhos (PNMs) isolados de amostras coletadas na Colômbia têm sido objeto de estudo desde a década de 1980; porém, esta informação não está integrada nem compilada. Esta revisão sistemática descreve os artigos publicados em revistas científicas até dezembro de 2019. 173 artigos atenderam aos critérios de inclusão de foco em PNMs obtidos de espécimes coletados em mares colombianos; artigos originais escritos em inglês, português ou espanhol. A maioria dos autores dos artigos eram pesquisadores de grupos colombianos, com baixa interação entre eles. 99,4% dos artigos estudavam amostras coletadas no Mar do Caribe. Foram estudadas 183 espécies, especialmente esponjas e octocorais. Nesta revisão, identificaram-se 1690 compostos (238 novos), principalmente diterpenos e derivados de esterol. 76,8% dos artigos mediram algumas atividades biológicas, incluindo antibiótica (34%) e anticancerígena (30%). Os artigos analisados foram publicados em 51 periódicos (74,6% internacionais). Em conclusão, o trabalho científico sobre PNM de origem colombiana cresceu ao longo do tempo. As oportunidades mais relevantes para preencher as lacunas existentes incluem: explorar organismos do Oceano Pacífico e os taxa pouco estudados; promover interação entre os grupos de pesquisa de PNMs e com grupos de outras áreas do conhecimento; e envolver o setor produtivo na pesquisa de PNMs.

Flavonoids and saponins from Passiflora edulis f. edulis leaves (purple passion fruit) and its potential anti-inflammatory activity.

OBJECTIVES: The objective of this work was to evaluate the anti-inflammatory activity of the aqueous extract, fractions and major compounds, which are isolated and identified from Passiflora edulis f. edulis (purple passion fruit) leaves extract. METHODS: For the isolation of the major compounds, reversed-phase chromatography and normal phase countercurrent chromatography were used. The separation was followed by thin layer chromatography and HPLC-DAD-ELSD. One-dimensional and two-dimensional NMR and ESI-TOF-MS/MS were used for structural elucidation. The anti-inflammatory activity was evaluated on a TPA multiple dose model of skin chronic inflammation in mice. Additionally, myeloperoxidase (MPO) and nitric oxide synthase (NOS) activity assays were performed as possible mechanisms of action studies. KEY FINDINGS AND CONCLUSIONS: The study of the butanolic fraction mainly showed the presence of saponins and flavonoids. Three minor flavonoids were detected; and three known saponins, cyclopassiflosides IX, XI and III were isolated and identified. This is the first unequivocal report of the presence of these compounds in P. edulis f. edulis leaves. The most favourable results of anti-inflammatory activity were obtained for the flavonoid-rich fraction. All the fractions and isolated compounds evaluated, presented high percentages of inhibition of nitric oxide synthase activity.

Integration of NMR studies, computational predictions, and in vitro assays in the search of marine diterpenes with antitumor activity.

Among the compounds of natural origin, diterpenes have proved useful as drugs for the treatment of cancer. Marine organisms, such as soft corals and algae, are a promising source of diterpenes, being a rich and unexplored source of cytotoxic agents. This study evaluated a library of 32 natural and semisynthetic marine diterpenes, including briarane, cembrane, and dolabellane nuclei, with the aim of determining their cytotoxicity against three human cancer cell lines (A549, MCF7, and PC3). The three most active compounds were submitted to a flow cytometry analysis in order to determine induction of apoptosis against the A549 cell line. An NMR analysis was conducted to determine and evaluate the interactions between active diterpenes and tubulin. These interactions were characterized by a computational study using molecular docking and MD simulations. With these results, two cembrane and one chlorinated briarane diterpenes were active against the three human cancer cell lines, induced apoptosis in the A549 cell line, and showed interactions with tubulin preferably at the taxane-binding site. This study is a starting point for the identification and optimization of the marine diterpenes selected for better antitumor activities. It also highlights the power of integrating NMR studies, computational predictions, and in vitro assays in the search for compounds with antitumor activity.

Semisynthesis of Dolabellane Diterpenes: Oxygenated Analogues with Increased Activity against Zika and Chikungunya Viruses.

Brown algae and soft corals represent the main marine sources of dolabellane diterpenes. The antiviral activity of dolabellanes has been studied for those isolated from algae, whereas dolabellanes isolated from soft corals have been barely studied. In this work, a collection of dolabellane diterpenes consisting of five natural and 21 semisynthetic derivatives was constructed, and their antiviral activities against Zika (ZIKV) and Chikungunya (CHIKV) viruses were tested. Dolabellatrienone (1) and (1R,7R,8R,11S)-7,8-epoxy-13-keto-dolabella-3,12(18)-diene (2), isolated from Eunicea genus soft corals, were employed to obtain 21 dolabellane and dolastane diterpenes by reactions such as allylic oxidations, reductions, acid-catalyzed epoxide ring opening, and acetylations. All of the compounds were identified by a combination of one- and two-dimensional NMR, mass spectrometry, and X-ray diffraction experiments. The cytotoxicites against Vero cells and the antiviral activities against ZIKV and CHIKV was tested to calculate the half-maximal effective concentration (EC50) and selectivity indexes (SIs). In general, the addition of oxygen-containing functional groups improved the bioactivity of dolabellane and dolastane diterpenes against ZIKV and CHIKV replication. Compound 9 showed an EC50 = 0.92 ± 0.08 µM and SI = 820 against ZIKV.

Identification of α-Amylase and α-Glucosidase Inhibitors and Ligularoside A, a New Triterpenoid Saponin from Passiflora ligularis Juss (Sweet Granadilla) Leaves, by a Nuclear Magnetic Resonance-Based Metabolomic Study.

The leaves of Passiflora ligularis Juss (known as sweet granadilla for its edible fruits) are a crop byproduct that is discarded. With the aim of contributing to give value-added products from these crop by-side products to farmers of Colombian Andes, we carried out a 1H-NMR-metabolomics analysis of polar extracts from leaves collected in three locations and stored in two conditions in order to identify glucosyl-hydrolase inhibitors. Variations in the metabolic profile and the bioactivity among samples were analyzed by orthogonal partial least square discriminant analysis. Thus, 1H-NMR signals related to polyphenolic compounds, saponins, and amino acids were correlated with higher inhibitory activities. Moreover, a targeted NMR and HPLC-MS/MS analysis allowed the identification of 14 polyphenolic compounds and the structural characterization of a new triterpenoid saponin, ligularoside A. The measurements of IC50 values for α-amylase and α-glycosidase inhibitors allowed the identification of quercetin-3-O-ß-glucoside, kaempferol-3-O-ß-glucoside, and ligularoside A as the most active compounds. These results suggest that P. ligularis leaves are a source of glucosyl-hydrolase inhibitors and lay the foundation for exploring additional applications.

NMR-based metabolic profiling to follow the production of anti-phytopathogenic compounds in the culture of the marine strain Streptomyces sp. PNM-9.

Actinobacteria are the major source of bioactive secondary metabolites and are featured in the search for antimicrobial compounds. We used nuclear magnetic resonance (RMN)-metabolic profiling and multivariate data analysis (MVDA) to correlate the metabolites' production of Streptomyces sp. PNM-9 from the algae Dictyota sp. and their biological activity against the rice phytopathogenic bacteria Burkholderia spp. The compounds 2-methyl-N-(2'-phenylethyl)-butanamide (1) and 3-methyl-N-(2'-phenylethyl)-butanamide (2) were identified through MVDA and 2D NMR experiments in the organic extract of a 15-days LB media culture of Streptomyces sp. PNM-9. Compounds 1 and 2 were isolated and their structures confirmed by one- and two-dimensional NMR and mass spectrometry (MS) data. Compounds 1 and 2 were active against the rice pathogenic bacteria Burkholderia glumae (ATCC 33,617) displaying minimal inhibitory concentration (MIC) values of 2.43 mM and 1.21 mM, respectively. The metabolomics-guided approach employing NMR-metabolic profiling was useful for marine microbial bioprospecting and suggested Streptomyces sp. PNM-9 strain and its compounds as a potential control against phytopathogenic bacteria.

Bioactive Potential of Extracts of Labrenzia aggregata Strain USBA 371, a Halophilic Bacterium Isolated from a Terrestrial Source.

Previous studies revealed the potential of Labrenzia aggregata USBA 371 to produce cytotoxic metabolites. This study explores its metabolic diversity and compounds involved in its cytotoxic activity. Extracts from the extracellular fraction of strain USBA 371 showed high levels of cytotoxic activity associated with the production of diketopiperazines (DKPs). We purified two compounds and a mixture of two other compounds from this fraction. Their structures were characterized by 1D and 2D nuclear magnetic resonance (NMR). The purified compounds were evaluated for additional cytotoxic activities. Compound 1 (cyclo (l-Pro-l-Tyr)) showed cytotoxicity to the following cancer cell lines: breast cancer 4T1 (IC50 57.09 ± 2.11 µM), 4T1H17 (IC50 40.38 ± 1.94), MCF-7 (IC50 87.74 ± 2.32 µM), murine melanoma B16 (IC50 80.87 ± 3.67), human uterus sarcoma MES-SA/Dx5 P-pg (-) (IC50 291.32 ± 5.64) and MES-SA/Dx5 P-pg (+) (IC50 225.28 ± 1.23), and murine colon MCA 38 (IC50 29.85 ± 1.55). In order to elucidate the biosynthetic route of the production of DKPs and other secondary metabolites, we sequenced the genome of L. aggregata USBA 371. We found no evidence for biosynthetic pathways associated with cyclodipeptide synthases (CDPSs) or non-ribosomal peptides (NRPS), but based on proteogenomic analysis we suggest that they are produced by proteolytic enzymes. This is the first report in which the cytotoxic effect of cyclo (l-Pro-l-Tyr) produced by an organism of the genus Labrenzia has been evaluated against several cancer cell lines.

Metabolic fingerprinting of banana passion fruits and its correlation with quorum quenching activity.

Banana passion fruit of the Passiflora genus, are commercially cultivated on a small to medium scale, mainly as edible fruits or as components of traditional herbal medicines. This subgenus comprises several species and hybrid specimens that grow readily in the wild. Due to their taxonomical complexity, many of these species have recently been reclassified (Ocampo Pérez and Coppens d'Eeckenbrugge, 2017), and their chemical profile has still to be determined. In this study, an 1H NMR-based platform was applied to the chemical profiling of seven wild species of the Passiflora subgenus, and UHPLC-DAD-MS was additionally used for the identification of phenolic compounds. A total of 59 compounds were detected including 26 O- and C-glycosidated flavonoids and polyphenols, nine organic acids, seven amino acids, GABA, sucrose, glucose, myo-inositol, and five other non-identified compounds. Two of the identified compounds are the previously undescribed C-glycosyl flavonoids, apigenin-4'-O-ß-glucopyranosyl, 8-C-ß-(6″acetyl)-glucopyranoside and apigenin-4-O-ß-glucopyranosyl-8-C-ß-neohesperidoside. These C-glycosyl flavonoids were isolated to confirm their proposed structures by NMR and LCMS analysis. The PCA score plots obtained from the 1H NMR data of the studied Passiflora samples showed P. cumbalensis and P. uribei as the species with the most distinguishable chemical profile. In addition, a correlation analysis using OPLS-DA was conducted between 1H-NMR data and the quorum quenching activity (QQ) of Chromobacterium violaceum ATCC 31532. This analysis revealed P. lehmannii, and P. uribei extracts to be the most active, and apigenin-4'-O-ß-glucopyranosyl, 8-C-ß-(6″acetyl)-glucopyranoside and apigenin-4-O-ß-glucopyranosyl-8-C-ß-neohesperidoside were identified as possibly responsible for the QQ activity. To confirm this, QQ activity of both compounds was tested against C. violaceum ATCC 3153. An inhibition of violacein production of 0.135 mM (100 µg/mL) and 0.472 mM (300 µg/mL) was observed for apigenin-4'-O-ß-glucopyranosyl,8-C-ß-(6″acetyl)-glucopyranoside and apigenin-4-O-ß-glucopyranosyl-8-C-ß-neohesperidoside respectively, while bacterial growth was unaffected in both cases. Furthermore, both compounds showed the ability to inhibit the production of the toxoflavin of the phytopathogen Burkholderia glumae ATCC 33617.

Metabolic Profiling of the Soft Coral Erythropodium caribaeorum (Alcyonacea: Anthothelidae) from the Colombian Caribbean Reveals Different Chemotypes.

The Caribbean soft coral Erythropodium caribaeorum is a rich source of erythrolides-chlorinated briarane diterpenoids. These compounds have an ecological role as feeding deterrents, with a wide variation in their composition depending on the location where the sample is collected. In Colombia, this soft coral can be found at different locations in the Caribbean Sea including Santa Marta, Islas del Rosario, and Providencia-three environmentally different coral reef areas in the south and southwest Caribbean Sea. In order to evaluate differences in erythrolide composition, the metabolic profiles of samples from each of these locations were analyzed by HPLC-MS. Principal component analysis showed changes in the diterpene composition according to the sample origin. Diterpenes from samples collected at each location were isolated to describe the three chemotypes. The chemotype from Santa Marta was highly diverse, with the new erythrolides W and X together with eight known erythrolides. The sample from Islas del Rosario showed a low diversity chemotype constituted by high amounts of erythrolide A and B. The chemotype from Providencia showed low chemical diversity with only two main compounds-erythrolide V and R. Evaluation of cytotoxic activity against the human cancer cell lines PC-3, MCF7, and A549 showed erythrolides A and B as the more active compounds with IC50 values in the range from 2.45 to 30 µM.

Production of Polyunsaturated Fatty Acids and Lipids from Autotrophic, Mixotrophic and Heterotrophic cultivation of Galdieria sp. strain USBA-GBX-832.

A search for extremophile organisms producing bioactive compounds led us to isolate a microalga identified as Galdieria sp. USBA-GBX-832 from acidic thermal springs. We have cultured Galdieria sp. USBA-GBX-832 under autotrophic, mixotrophic and heterotrophic conditions and determined variations of its production of biomass, lipids and PUFAs. Greatest biomass and PUFA production occurred under mixotrophic and heterotrophic conditions, but the highest concentration of lipids occurred under autotrophic conditions. Effects of variations of carbon sources and temperature on biomass and lipid production were evaluated and factorial experiments were used to analyze the effects of substrate concentration, temperature, pH, and organic and inorganic nitrogen on biomass production, lipids and PUFAs. Production of biomass and lipids was significantly dependent on temperature and substrate concentration. Greatest accumulation of PUFAs occurred at the lowest temperature tested. PUFA profiles showed trace concentrations of arachidonic acid (C20:4) and eicosapentaenoic acid (C20:5). This is the first time synthesis of these acids has been reported in Galdieria. These findings demonstrate that under heterotrophic conditions this microalga's lipid profile is significantly different from those observed in other species of this genus which indicates that the culture conditions evaluated are key determinants of these organisms' responses to stress conditions and accumulation of these metabolites.

Cyclic tetrapeptides from the marine strain Streptomyces sp. PNM-161a with activity against rice and yam phytopathogens.

Two cyclotetrapeptides, henceforth named Provipeptides A (1) and B (2), along with five known diketopiperazines (3-7) were isolated from the liquid culture of marine Streptomyces sp. 161a recovered from a sample of sea grass Bryopsis sp. The structures of cyclotetrapeptides and diketopiperazines (DKPs) were established by 1D and 2D NMR data, MS, and by comparison with literature data. The absolute stereochemistry of compounds cyclo-(L-Pro-L-Leu-D-Pro-L-Phe) 1 and cyclo-(-Pro-Ile-Pro-Phe) 2 was established by the Marfey's method. Compound 1 showed antibacterial activity against rice phytopathogenic strains Burkholderia glumae (MIC = 1.1 mM) and Burkholderia gladioli (MIC = 0.068 mM), compound 2 was active only against B. glumae (MIC = 1.1 mM), and DKP cyclo-[L-Pro-L-Leu] 5 showed to be active against B. gladioli (MIC = 0.3 mM) and B. glumae (MIC = 2.4 mM). Compounds 1 and 2 showed 65% and 50% inhibition of Colletotrichum gloeosporioides (yam pathogen) conidia germination, respectively at a concentration of 1.1 mM.

Plant-Growth Promotion and Biocontrol Properties of Three Streptomyces spp. Isolates to Control Bacterial Rice Pathogens.

Bacterial Panicle Blight caused by Burkholderia glumae is a major disease of rice, which has dramatically affected rice production around the world in the last years. In this study we describe the assessment of three Streptomyces isolates as biocontrol agents for B. glumae. Additionally, the presence of other plant-growth promoting abilities and their possible beneficial effects upon their inoculation on rice plants was evaluated as an ecological analysis for their future inoculation in rice crops. Two isolates (A20 and 5.1) inhibited growth of virulent B. glumae strains, as well as a wide range of bacterial and fungal species, while a third strain (7.1) showed only antifungal activity. In vitro tests demonstrated the ability of these strains to produce siderophores, Indoleacetic acid (IAA), extracellular enzymes and solubilizing phosphate. Greenhouse experiments with two rice cultivars indicated that Streptomyces A20 is able to colonize rice plants and promote plant growth in both cultivars. Furthermore, an egfp tagged mutant was generated and colonization experiments were performed, indicating that Streptomyces A20 -GFP was strongly associated with root hairs, which may be related to the plant growth promotion observed in the gnotobiotic experiments. In order to characterize the antimicrobial compounds produced by strain A20 bacteria, mass spectrometry analyses were performed. This technique indicated that A20 produced several antimicrobial compounds with sizes below 3 kDa and three of these molecules were identified as Streptotricins D, E and F. These findings indicate the potential of Streptomyces A20 as a biocontrol inoculant to protect rice plants against bacterial diseases.

Peruvioses A to F, sucrose esters from the exudate of Physalis peruviana fruit as α-amylase inhibitors.

The fruit of Physalis peruviana is widely used in traditional Colombian medicine as an antidiabetic treatment. The aim of the study reported here was to identify the compounds responsible for the hypoglycemic activity using the α-amylase inhibition test. Bioguided fractionation of a dichloromethane extract of the sticky exudate that covers the fruit allowed the isolation and identification of three new sucrose esters, named as peruvioses C-E (1-3), along with the known peruvioses A (6), B (5) and F (4), the structures of which were elucidated by extensive NMR and MS experiments. These compounds proved to be responsible for the hypoglycemic activity observed in the extract. Peruviose D (2) showed the highest activity, with an inhibitory activity value of 84.8%. This is the first study to establish the potential of sucrose esters as α-amylase inhibitors and to explain the hypoglycemic effect that has traditionally been attributed to gooseberry fruit.

Correction to: Microbial diversity of saline environments: searching for cytotoxic activities.

The original version of this article (Diaz-Cardenas et al. 2017) unfortunately contained a mistake in Fig. 1. The pie chart of Fig. 1 should explain the distribution of the relative abundance of the Bacteria and Archaea strains isolated at Zipaquirá salt mine: Proteobacteria 39%; Actinobacteria 9%, Bacteroidetes 1%, Archaea 3% and Firmicutes 48% instead of NOMBRE DE CATEGORIA [PORCENTAJE]. The corrected Fig. 1 and caption are given below.

Microbial diversity of saline environments: searching for cytotoxic activities.

In order to select halophilic microorganisms as a source of compounds with cytotoxic activities, a total of 135 bacterial strains were isolated from water and sediment samples collected from the Zipaquirá salt mine in the Colombian Andes. We determined the cytotoxic effects of 100 crude extracts from 54 selected organisms on the adherent murine mammary cell carcinoma 4T1 and human mammary adenocarcinoma MCF-7 cell lines. These extracts were obtained from strains of Isoptericola, Ornithinimicrobium, Janibacter, Nesterenkonia, Alkalibacterium, Bacillus, Halomonas, Chromohalobacter, Shewanella, Salipiger, Martellela, Oceanibaculum, Caenispirillum and Labrenzia. The extracts of 23 strains showed an IC50 of less than 100 µg mL-1. They were subsequently analyzed by LC/MS allowing dereplication of 20 compounds. The cytotoxic effect was related to a complex mixture of diketopiperazines present in many of the extracts analyzed. The greatest cytotoxic activity against both of the evaluated cell lines was obtained from the chloroform extract of Labrenzia aggregata USBA 371 which had an IC50 < 6 µg mL-1. Other extracts with high levels of cytotoxic activity were obtained from Bacillus sp. (IC50 < 50 µg mL-1) which contained several compounds such as macrolactin L and A, 7-O-succinoylmacrolactin F and iturin. Shewanella chilikensis USBA 344 also showed high levels of cytotoxic activity against both cell lines in the crude extract: an IC50 < 15 µg mL-1 against the 4T1 cell line and an IC50 < 68 µg mL-1 against the MCF-7 cell line. Nesterenkonia sandarakina CG 35, which has an IC50 of 118 µg mL-1 against 4T1, is a producer of diketopiperazines and 1-acetyl-ß-carboline. Also, Ornithinimicrobium kibberense CG 24, which has IC50 < 50 µg mL-1, was a producer of diketopiperazines and lagunamycin. Our study demonstrates that these saline environments are habitats of halophilic and halotolerant bacteria that have previously unreported cytotoxic activity.

Monoaminergic neurotransmission is mediating the antidepressant-like effects of Passiflora edulis Sims fo. edulis.

The genus Passiflora is popularly used to treat anxiety. Recent studies showed antidepressant-like effects of two varieties of P. edulis (edulis and flavicarpa) in mice. However, the mechanisms of antidepressant actions are still unknown. Here, the effects of P. edulis fo. edulis aqueous extract (AE, 100-300mg/kg, po), and ethyl acetate (AcOEt, 25-50mg/kg, po), butanol (BuOH, 25-50mg/kg, po) and residual aqueous (25-100mg/kg, po) fractions were investigated in the mouse forced swimming test. In addition, the involvement of monoamines in the P. edulis fractions-induced antidepressant actions was approached. HPLC analyses showed that AcOEt and BuOH, but not residual, fractions shared with AE the main peaks between 25 and 70min (UV 340nm), which are suggestive of flavonoids. Nortriptyline and fluoxetine reduced the immobility time and similar results were observed for AE, AcOEt and BuOH but not residual fractions. PCPA (inhibitor of 5-HT synthesis), AMPT (inhibitor of catecholamine synthesis) and sulpiride (selective D2 receptor antagonist), but not DSP-4 (noradrenergic neurotoxin), blocked the antidepressant actions of AcOEt and BuOH. In conclusion, AcOEt and BuOH fractions shared with AE similar phytochemical composition and antidepressant actions. Preserved 5-HT and dopamine transmissions were required for the antidepressant effects of P. edulis fractions.

Dolabellane diterpenes from the Caribbean soft corals Eunicea laciniata and Eunicea asperula and determination of their anti HSV-1 activity / Dolabellanos de los octocorales caribenos Eunicea laciniata y Eunicea asperula y determinación de su actividad anti VHS-1 / Dolabellanos dos octocorais caribenhos Eunicea laciniata e Eunicea asperula e determinação de sua atividade anti HSV-1

Abstract Dolabellane diterpenes have considerable antiviral activity, but most studies have been focused towards compounds isolated from Dictyota brown algae. Although soft corals are also a significant source of these diterpenes, their antiviral potential has not been studied in detail. With the aim of assessing the biological activity of marine sources, we evaluated the dolabellane content in the soft corals Eunicea laciniata and E. asperula collected in Santa Marta, Colombian Caribbean. Dolabellanes 1-6 were isolated from E. laciniata while compounds 2, 4 and 5 were isolated from E. asperula. All compounds were identified by NMR, GC-EIMS, optical rotation and comparison with previously reported dolabellanes. GC-EIMS analyses showed that dolabellatrienone (2) transforms into compounds 4 and 5 as oxidation products upon prolonged storage; however, those compounds were also naturally present in the extract of the studied organisms. Pure dolabellanes were tested in vitro in antiviral assays against HSV-1. Compound 6 inhibited virus replication in infected cells (73.7% of inhibition at 50 µM) without cytotoxic effect (CC50 = 95 9), showing similar activity to the positive control Acyclovir®. Thus, compound 6 is an interesting candidate for further studies of dolabellanes as antivirals.

Resumen Los dolabellanos son diterpenos con actividad antiviral, la mayor parte de los estudios se han realizado con compuestos aislados de algas pardas del genero Dictyota. Los corales blandos son también una importante fuente de dolabellanos, pero el potencial antiviral de estos ha sido muy poco estudiado. Se llevó a cabo el estudio químico de los dolabellanos presentes en los octocorales Eunicea laciniata y Eunicea asperula, recolectados en Santa Marta, Caribe colombiano. Los dolabellanos 1-6 fueron aislados del octocoral E. laciniata mientras que en E. asperula se encontraron los compuestos 2, 4 y 5. La elucidaci6n estructural se llev6 a cabo mediante RMN, espectrometría de masas, rotaci6n 6ptica y comparaci6n con reportes previos. El análisis por CG-EM evidenci6 que la dolabellatrienona (2) se puede transformar en los compuestos 4 y 5 como producto del almacenamiento prolongado, no obstante, tales compuestos también estuvieron presentes en los extractos de los organismos estudiados. El compuesto 6 inhibi6 la replicaci6n del VHS-1 (73,7% de inhibición en células infectadas a una concentraci6n de 50 µM) sin efecto citot6xico (CC50 = 959), mostrando una citotoxicidad similar al Aciclovir®, un control positivo, por lo cual es un candidato para la realizaci6n de estudios adicionales sobre el potencial antiviral de los dolabellanos.

Resumo Os dolabellanos são diterpenos que têm mostrado atividade antiviral, os estudos neste campo estão centrados nos compostos isolados de algas do gênero Dictyota. Os octocorais também são uma fonte importante de dolabellanos, mas não tem sido estudados. Foirealizado o estudo químico dos octocorais Eunicea laciniata e Eunicea asperula, coletados em Santa Marta, Caribe Colombiano. O estudo químico dos dois organismos permitiu o isolamento dos dolabellanos 1-6 de E. laciniata, enquanto que para E. aspérula foram identificados os compostos 2, 4 e 5. A elucidação estrutural foi realizada mediante RMN, espectrometria de massas, rotação óptica e comparação com os dados da literatura. A análise por GC-MS evidenciou que a dolabelatrienona (2) pode gerar os compostos 4 e 5 como produto de degradação, a partir de um armazenamento prolongado. No entanto, os compostos também estavam presentes nos extratos dos organismos estudados. O composto 6 mostrou uma citotoxicidade similar ao Aciclovir®, um controle positivo, numa porcentagem de inibição da replicação do HVS-1 (73,7% de inibição em células infectadas na concentração de 50 µM) sem efeito citotóxico (CC50 = 959), o quetorna esse composto um candidato para o desenvolvimento de antivirais.

Marine Actinobacteria as a source of compounds for phytopathogen control: An integrative metabolic-profiling / bioactivity and taxonomical approach.

Marine bacteria are considered as promising sources for the discovery of novel biologically active compounds. In this study, samples of sediment, invertebrate and algae were collected from the Providencia and Santa Catalina coral reef (Colombian Caribbean Sea) with the aim of isolating Actinobateria-like strain able to produce antimicrobial and quorum quenching compounds against pathogens. Several approaches were used to select actinobacterial isolates, obtaining 203 strains from all samples. According to their 16S rRNA gene sequencing, a total of 24 strains was classified within Actinobacteria represented by three genera: Streptomyces, Micromonospora, and Gordonia. In order to assess their metabolic profiles, the actinobacterial strains were grown in liquid cultures, and LC-MS-based analyses from ethyl acetate fractions were performed. Based on taxonomical classification, screening information of activity against phytopathogenic strains and quorum quenching activity, as well as metabolic profiling, six out of the 24 isolates were selected for follow-up with chemical isolation and structure identification analyses of putative metabolites involved in antimicrobial activities.