Lentinoids A-D, New Natural Products Isolated from Lentinus strigellus.

Four novel lentinoids (1-4), along with the known compounds striguellone A (5), isopanepoxydone (6) and panepoxydone (7), were isolated as part of our studies on Lentinus strigellus. The structures of 1-4 have been established by 1D- and 2D-NMR and MS analysis. Compounds (1-3) and (5-7) were tested against Listeria monocytogenes, Enterococcus faecalis, Pseudomonas aeruginosa and Klebsiella pneumoniae. These compounds showed inhibition diameters ranging from 7.5-9.5 mm, however, when the minimum inhibitory concentration (MIC) was determined, only compound 1 showed a significant activity of 200 µg/mL. Intermediates for the biosynthesis of the oxygenated cyclohexenyl derivatives isolated from lentinoid fungi (genera Lentinus and Panus) are proposed.

Mycoleptodiscins A and B, cytotoxic alkaloids from the endophytic fungus Mycoleptodiscus sp. F0194.

Two novel reddish-orange alkaloids, mycoleptodiscin A (1) and mycoleptodiscin B (2), were isolated from liquid cultures of the endophytic fungus Mycoleptodiscus sp. that had been isolated from Desmotes incomparabilis in Panama. Elucidation of their structures was accomplished using 1D and 2D NMR spectroscopy in combination with IR spectroscopic and MS data. These compounds are indole-terpenes with a new skeleton uncommon in nature. Mycoleptodiscin B (2) was active in inhibiting the growth of cancer cell lines with IC50 values in the range 0.60-0.78 µM.

Coibanoles, a new class of meroterpenoids produced by Pycnoporus sanguineus.

Three new terpenoids of mixed biosynthetic origin were isolated from the culture filtrate of the endophytic fungus Pycnoporus sanguineus. Their structures were determined by extensive spectroscopic analyses. We have named these tricyclic and tetracyclic metabolites 'coibanoles A-C' in reference to Coiba Island and Coiba National Park, Panamá, from which the plant and endophyte were collected. The extract was inactive to the human parasites Trypanosoma cruzi, Leishmania donovani, and Plasmodium falciparum at a test concentration of 10 µg/mL.

Antagonistic effects of native strains of the soil fungus Paecilomyces against gastrointestinal nematode and protozoan parasites of pigs in Panama.

A variety of gastrointestinal parasites naturally infect domestic pigs in Panama which may also occur as zoonotic infections in humans. Anthelmintic drug treatment, including mass drug administration, can lead to drug resistance, reflecting a need for alternatives. The objectives of this exploratory and observational study were: (1) to isolate and cultivate natives species of Paecilomyces from natural soils in Panama, and (2) to evaluate isolated strains for their capacity to parasitize endemic gastrointestinal nematode and protozoan parasites recovered from naturally infected domestic pigs by observing cultures for spore adhesion and hyphae penetration phases. Using microcultivation and inoculation techniques, four strains of Paecilomyces were isolated from three locations in Panama, out of which three successfully adhered to and penetrated free-living stages (eggs, cysts and oocysts) of Balantidium suis, coccidia, Trichuris suis and hookworm. To our knowledge, this is the first published report of a nematophagous fungus such as Paecilomyces successfully infecting this range of gastrointestinal parasites, particularly protozoan parasites.

Exploring the Antibacterial Activity of Pestalotiopsis spp. under Different Culture Conditions and Their Chemical Diversity Using LC-ESI-Q-TOF-MS.

As a result of the capability of fungi to respond to culture conditions, we aimed to explore and compare the antibacterial activity and chemical diversity of two endophytic fungi isolated from Hyptis dilatata and cultured under different conditions by the addition of chemical elicitors, changes in the pH, and different incubation temperatures. Seventeen extracts were obtained from both Pestalotiopsis mangiferae (man-1 to man-17) and Pestalotiopsis microspora (mic-1 to mic-17) and were tested against a panel of pathogenic bacteria. Seven extracts from P. mangiferae and four extracts from P. microspora showed antibacterial activity; while some of these extracts displayed a high-level of selectivity and a broad-spectrum of activity, Pseudomonas aeruginosa was the most inhibited microorganism and was selected to determine the minimal inhibitory concentration (MIC). The MIC was determined for extracts man-6 (0.11 µg/mL) and mic-9 (0.56 µg/mL). Three active extracts obtained from P. mangiferae were analyzed by Liquid Chromatography-Electrospray Ionization-Quadrupole-Time of Flight-Mass Spectrometry (LC-ESI-Q-TOF-MS) to explore the chemical diversity and the variations in the composition. This allows us to propose structures for some of the determined molecular formulas, including the previously reported mangiferaelactone (1), an antibacterial compound.

A survey of intestinal parasites including associated risk factors in humans in Panama.

BACKGROUND: Intestinal parasitic infections are among the most common infections worldwide, leading to illness with serious and long lasting implications in children and immunocompromised people. Transmission of intestinal parasites is more frequent in tropical and sub-tropical areas where sanitation is poor and socioeconomic conditions are deficient. Panama is a country where climate and social conditions could be reflected in a high number of people infected with intestinal parasites. The presence, prevalence, and distribution of intestinal parasites in this country have been approached to date only in very restricted areas and population groups, but the impact of intestinal parasite infections at the national level is unknown. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a cross-sectional survey between 2008 and 2010 to determine the prevalence of intestinal parasites across Panama. Overall, 14 municipalities in seven provinces of Panama were surveyed. The presence of eggs, cysts, and larvae was assessed by microscopy in 1123 human fecal samples using a concentration technique. A questionnaire to identify risk factors associated with the frequency of intestinal parasites in the study population was also prepared and performed. Overall, 47.4% of human samples presented parasites. Variables including community type, age group, occupation, co-presence of commensals and socioeconomic factors (use of shoes and type of sanitation) were significantly associated with intestinal parasites (p<0.05). CONCLUSIONS/SIGNIFICANCE: The preliminary data obtained in the current study, showing a high prevalence of fecal-oral transmitted parasites in Panama, place intestinal parasitism as a major health problem in this country. Specific interventions should be planned for the indigenous population, the group most afflicted by intestinal parasites.