Polyphenols with Anti-Inflammatory Properties: Synthesis and Biological Activity of Novel Curcumin Derivatives.

Herein, we describe the synthesis and evaluation of anti-inflammatory activities of new curcumin derivatives. The thirteen curcumin derivatives were synthesized by Steglich esterification on one or both of the phenolic rings of curcumin with the aim of providing improved anti-inflammatory activity. Monofunctionalized compounds showed better bioactivity than the difunctionalized derivatives in terms of inhibiting IL-6 production, and known compound 2 presented the highest activity. Additionally, this compound showed strong activity against PGE2. Structure-activity relationship studies were carried out for both IL-6 and PGE2, and it was found that the activity of this series of compounds increases when a free hydroxyl group or aromatic ligands are present on the curcumin ring and a linker moiety is absent. Compound 2 remained the highest activity in modulating IL-6 production and showed strong activity against PGE2 synthesis.

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.

Identification of Secondary Metabolites from the Mangrove-Endophyte Lasiodiplodia iranensis F0619 by UPLC-ESI-MS/MS.

Lasiodiplodia is a widely distributed fungal genus, frequently found in tropical and subtropical regions where it can cause disease in important crops. It represents a promising source of active secondary metabolites with uses in chemical, pharmaceutical, and agrochemical processes. In this study, the strain Lasiodiplodia iranensis F0619 was isolated from the mangrove Avicennia ger-minans, collected from Sarigua National Park in the Republic of Panama. Fractions of crude extract were analyzed by UPLC-ESI-MS/MS, and five compounds, previously reported from Lasiodiplodia genus were identified, including 11,12-didehydro-7-iso-jasmonic acid (1), 4,5-didehydro-7-iso-jasmonic acid (2), cyclo-(L-Leu-L-Pro) (3), jasmonate-threonine (4), and abscisic acid (5). We describe and analyze their MS/MS fragmentation patterns to confirm the compounds 'chemical structures.

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.

Screening and evaluation of antiparasitic and in vitro anticancer activities of Panamanian endophytic fungi.

Many compounds produced by fungi have relevant pharmaceutical applications. The purpose of this study was to collect and isolate endophytic fungi from different regions of Panama and then to test their potential therapeutic activities against Leishmania donovani, Plasmodium falciparum, and Trypanosoma cruzi as well as their anticancer activities in MCF-7 cells. Of the 25 fungal isolates obtained, ten of them had good anti-parasitic potential, showing selective activity against L. donovani; four had significant anti-malarial activity; and three inhibited the growth of T. cruzi. Anticancer activity was demonstrated in four isolates. Of the active isolates, Edenia sp. strain F0755, Xylaria sp. strain F1220, Aspergillus sp. strain F1544, Mycoleptodiscus sp. strain F0194, Phomopsis sp. strain F1566, Pycnoporus sp. strain F0305, and Diaporthe sp. strain F1647 showed the most promise based on their selective bioactivity and lack of toxicity in the assays.

Two genera of Aulacoscelinae beetles reflexively bleed azoxyglycosides found in their host cycads.

Aulacoscelinae beetles have an ancient relationship with cycads (Cycadophyta: Zamiaceae), which contain highly toxic azoxyglycoside (AZG) compounds. How these "primitive" leaf beetles deal with such host-derived compounds remains largely unknown. Collections were made of adult Aulacoscelis appendiculata from Zamia cf. elegantissima in Panama, A. vogti from Dioon edule in Mexico, and Janbechynea paradoxa from Zamia boliviana in Bolivia. Total AZG levels were quantified in both cycad leaves and adult beetles by high performance liquid chromatography (HPLC). On average, cycad leaves contained between 0.5-0.8% AZG (frozen weight, FW), while adult beetles feeding on the same leaves contained even higher levels of the compounds (average 0.9-1.5% FW). High AZG levels were isolated from reflex bleeding secreted at the leg joints when beetles were disturbed. Nuclear magnetic resonance and mass spectroscopy identified two AZGs, cycasin and macrozamin, in the reflex bleeding; this is the first account of potentially plant-derived compounds in secretions of the Aulacoscelinae. These data as well as the basal phylogenetic position of the Aulacoscelinae suggest that sequestration of plant secondary metabolites appeared early in leaf beetle evolution.

Structurally Uncommon Secondary Metabolites Derived from Endophytic Fungi.

Among microorganisms, endophytic fungi are the least studied, but they have attracted attention due to their high biological diversity and ability to produce novel and bioactive secondary metabolites to protect their host plant against biotic and abiotic stress. These compounds belong to different structural classes, such as alkaloids, peptides, terpenoids, polyketides, and steroids, which could present significant biological activities that are useful for pharmacological or medical applications. Recent reviews on endophytic fungi have mainly focused on the production of novel bioactive compounds. Here, we focus on compounds produced by endophytic fungi, reported with uncommon bioactive structures, establishing the neighbor net and diversity of endophytic fungi. The review includes compounds published from January 2015 to December 2020 that were catalogued as unprecedented, rare, uncommon, or possessing novel structural skeletons from more than 39 different genera, with Aspergillus and Penicillium being the most mentioned. They were reported as displaying cytotoxic, antitumor, antimicrobial, antiviral, or anti-inflammatory activity. The solid culture, using rice as a carbon source, was the most common medium utilized in the fermentation process when this type of compound was isolated.

Domestication Syndrome in Caimito (Chrysophyllum cainito L.): Fruit and Seed Characteristics.

Domestication Syndrome in Caimito (Chrysophyllum cainitoL.): Fruit and Seed Characteristics: The process of domestication is understudied and poorly known for many tropical fruit tree crops. The star apple or caimito tree (Chrysophyllum cainito L., Sapotaceae) is cultivated throughout the New World tropics for its edible fruits. We studied this species in central Panama, where it grows wild in tropical moist forests and is also commonly cultivated in backyard gardens. Using fruits collected over two harvest seasons, we tested the hypothesis that cultivated individuals of C. cainito show distinctive fruit and seed characteristics associated with domestication relative to wild types. We found that cultivated fruits were significantly and substantially larger and allocated more to pulp and less to exocarp than wild fruits. The pulp of cultivated fruits was less acidic; also, the pulp had lower concentrations of phenolics and higher concentrations of sugar. The seeds were larger and more numerous and were less defended with phenolics in cultivated than in wild fruits. Discriminant Analysis showed that, among the many significant differences, fruit size and sugar concentration drove the great majority of the variance distinguishing wild from cultivated classes. Variance of pulp phenolics among individuals was significantly higher among wild trees than among cultivated trees, while variance of fruit mass and seed number was significantly higher among cultivated trees. Most traits showed strong correlations between years. Overall, we found a clear signature of a domestication syndrome in the fruits of cultivated caimito in Panama.

Patents on Endophytic Fungi for Agriculture and Bio- and Phytoremediation Applications.

Plant endophytic fungi spend all or part of their lives inside host tissues without causing disease symptoms. They can colonize the plant to protect against predators, pathogens and abiotic stresses generated by drought, salinity, high concentrations of heavy metals, UV radiation and temperature fluctuations. They can also promote plant growth through the biosynthesis of phytohormones and nutrient acquisition. In recent years, the study of endophytic fungi for biological control of plant diseases and pests has been intensified to try to reduce the ecological and public health impacts due the use of chemicals and the emergence of fungicide resistance. In this review, we examine 185 patents related to endophytic fungi (from January 1988 to December 2019) and discuss their applicability for abiotic stress tolerance and growth promotion of plants, as agents for biocontrol of herbivores and plant pathogens and bio- and phytoremediation applications.

Patents on Endophytic Fungi Related to Secondary Metabolites and Biotransformation Applications.

Endophytic fungi are an important group of microorganisms and one of the least studied. They enhance their host's resistance against abiotic stress, disease, insects, pathogens and mammalian herbivores by producing secondary metabolites with a wide spectrum of biological activity. Therefore, they could be an alternative source of secondary metabolites for applications in medicine, pharmacy and agriculture. In this review, we analyzed patents related to the production of secondary metabolites and biotransformation processes through endophytic fungi and their fields of application. We examined 245 patents (224 related to secondary metabolite production and 21 for biotransformation). The most patented fungi in the development of these applications belong to the Aspergillus, Fusarium, Trichoderma, Penicillium, and Phomopsis genera and cover uses in the biomedicine, agriculture, food, and biotechnology industries.

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.

Antileishmanial constituents of the Panamanian endophytic fungus Edenia sp.

Bioassay-directed fractionation of extracts from the fermentation broth and mycelium of the fungus Edenia sp. led tothe isolation of five antileishmanial compounds, preussomerin EG1 (1), palmarumycin CP2 (2), palmarumycin CP17 (3), palmarumycin CP18 (4), and CJ-12,371 (5). Compounds 3 and 4 are new natural products, and this is only the second report of compound 1. The structures of compounds 1-5 were established by spectroscopic analyses (HRMS and NMR). All metabolites caused significant inhibition of the growth of Leishmania donoVani in the amastigote form, with IC50 values of 0.12, 3.93, 1.34, 0.62, and 8.40 microM, respectively. Compounds 1-5 were inactive when tested against Plasmodium falciparum or Trypanasoma cruzi at a concentration of 10 microg/mL, indicating that they have selective activity against Leishmania parasites. Compounds 1-5 showed weak cytotoxicity to Vero cells (IC50 of 9, 162, 174, 152, and 150 microM, respectively); however, the therapeutic window of these compounds is quite significant with 75, 41, 130, 245, and 18 times (respectively) more antileishmanial activity than cytotoxicity.

Anti-L. donovani activity in macrophage/amastigote model of palmarumycin CP18 and its large scale production.

Palmarumycin CP18, isolated from an extract of the fermentation broth and mycelium of the Panamanian endophytic fungus Edenia sp., was previously reported with strong and specific activity against Leishmania donovani. Here we report that when the same strain was cultured on different solid media--Harrold Agar, Leonian Agar, Potato dextrose Agar (PDA), Corn Meal Agar, Honey Peptone Agar, and eight vegetables (V8) Agar--in order to determine the optimal conditions for isolation of palmarumycin CP18, no signal for this compound was observed in any of the 1H NMR spectra of fractions obtained from these extracts. However, one extract, prepared from the fungal culture in PDA contained significant amounts of CJ-12,372, a possible biosynthetic precursor of palmarumycin CP18. Edenia sp. was cultivated on a large scale on PDA and CJ-12,372 was converted to palmarumycin CP18 by oxidation of its p-hydroquinone moiety with DDQ in dioxane. Palmarumycin CP18 showed anti-leishmanial activity against L. donovani in a macrophage/amastigote model, with IC50 values of 23.5 microM.

Ecology- and bioassay-guided drug discovery for treatments of tropical parasitic disease: 5alpha,8alpha-epidioxycholest-6-en-3beta-ol isolated from the mollusk Dolabrifera dolabrifera shows significant activity against Leishmania donovani.

An ecology- and bioassay-guided search employed to discover compounds with activity against tropical parasitic diseases and cancer from the opisthobranch mollusk, Dolabrifera dolabrifera, led to the discovery of antileishmanial properties in the known compound, 5alpha,8alpha-epidioxycholest-6-en-3beta-ol (1). Compound 1 was identified through nuclear magnetic resonance spectroscopy (1H, 13C) and mass spectrometry. The compound was concentrated in the digestive gland of D. dolabrifera, but was not detected in other body parts, fecal matter or mucus. Compound 1 showed an IC50 of 4.9 microM towards the amastigote form of Leishmania donovani compared with an IC50 of 281 microM towards the control Vero cell line, a 57.3-fold difference, and demonstrated no measurable activity against Plasmodium falciparum, Trypanosoma cruzi, and the breast cancer cell line, MCF-7.

Antiparasitic and anticancer constituents of the endophytic fungus Aspergillus sp. strain F1544.

With the combined goal of finding the best anti-parasitic and anti-cancer activities as well as isolating the bioactive agents and studying their structures and biological properties, we proceeded to perform a small-scale cultivation of Aspergillus sp. strain F1544 using Potato Dextrose, Malt Extract, Czapek Dox and Eight Vegetables media. From the more promising extracts (obtaining using potato dextrose and czapek dox media in large scale) of this fungus, we isolated the five compounds: pseurotin A (1), 14-norpseurotin A (2), FD-838 (3), and pseurotin D (4), and fumoquinone B (5). All compounds showed good antileishmanial and moderate anticancer activities.

Chemical constituents of the new endophytic fungus Mycosphaerella sp. nov. and their anti-parasitic activity.

Chemical investigation of a new endophytic fungus, Mycosphaerella sp. nov. strain F2140, associated with the foliage of the plant Psychotria horizontalis (Rubiaceae) in Panama, resulted in the isolation of cercosporin (1) and a new cercosporin analog (3) as the major components. The structures of minor compounds in the extract were elucidated by detailed spectroscopic analysis as 2-(2-butyl)-6-ethyl-3-hydroxy-6-methylcyclohex-2-ene-1,5-dione (4), 3-(2-butyl)-6-ethyl-5-hydroxy-2-methoxy-6-methyl-cyclohex-2-enone (5), and an isomer of 5 (6). To study the influence of the hydroxy groups on the anti-parasitic activity of cercosporin, compound 1 was acetylated to obtain derivative 2. The isolated compounds 1- 6 were tested in vitro to determine their anti-parasitic activity against the causal agents of malaria (Plasmodium falciparum), leishmaniasis (Leishmania donovani), and Chagas disease (Trypanosoma cruzi). Cytotoxicity and potential anticancer activity of these compounds were evaluated using mammalian Vero cells and MCF7 cancer cell lines, respectively. Compounds 1 and 2 displayed high potency against L. donovani (IC50 0.46 and 0.64 microM), T. cruzi (IC50 1.08 and 0.78 microM), P. falciparum (IC50 1.03 and 2.99 microM), and MCF7 cancer cell lines (IC50 4.68 and 3.56 microM). Compounds 3-6 were not active in these assays at a concentration of 10 microg/mL.

Hydroxyalkenylresorcinols from Stylogyne turbacensis.

Two new compounds, 5-(11'(S)-hydroxy-8'-heptadecenyl)resorcinol (3) and 5-(12'(S)-hydroxy-8',14'-heptadecadienyl)resorcinol (4), were isolated from the leaves of Stylogyne turbacensis together with the known analogue metabolites 1 and 2. Compounds 3 and 4 showed the strongest activity in the leishmania assay, 7 and 3 microM, respectively, while compounds 1, 2, and 4 showed moderate activity against a drug-resistant strain of Trypanosoma cruzi with IC(50) values of 30, 25, and 22 microM, respectively. Additional testing in MCF-7 and NCI-H460 was performed for compounds 3 and 4. The structures of compounds 1-4 were elucidated using NMR, MS, and other spectroscopic data. The absolute stereochemistry of compounds 3 and 4 was also investigated using the Mosher ester approach. Peracetylated derivatives of these four metabolites were produced and their activities determined in the Trypanosoma cruzi assay.

Weakly antimalarial flavonol arabinofuranosides from Calycolpus warszewiczianus.

Three new flavonol arabinosides (2-4) were isolated from the young leaves of Calycolpus warszewiczianus. The structures were determined as myricetin-3-O-alpha-L-3' '-acetylarabinofuranoside (2), myricetin-3-O-alpha-L-3' ',5' '-diacetylarabinofuranoside (3), and 5-galloylquercetin-3-O-alpha-L-arabinofuranoside (4). Molecular structures were elucidated using NMR spectroscopy in combination with IR and MS data. Two known compounds, myricetin-3-O-alpha-L-arabinofuranoside (1) and (-)-epi-catechin (5), were also isolated. The compounds were tested in vitro against a chloroquine-resistant strain of Plasmodium falciparum, Leishmania mexicana, and Trypanosoma cruzi parasites. Compound 4 demonstrated weak activity against a chloroquine-resistant strain of P. falciparum (14.5 microM), whereas none of the compounds demonstrated activity against L. mexicana and T. cruzi at the concentrations of 40 and 50 microg/mL, respectively, and no cytotoxicity was detected against mammalian cells below 100 microg/mL.

Novel cassane and cleistanthane diterpenes from Myrospermum frutescens: absolute stereochemistry of the cassane diterpene series.

Four new diterpenes (1-4) were isolated from the leaves of Myrospermum frutescens as minor constituents. Chagresnol (1), 6beta,18-diacetoxycassan-13,15-diene (2), and chagreslactone (3) possess cassane skeletons, while chagresnone (4) exhibits a cleistanthane skeleton. Molecular structures and their relative stereochemistries were elucidated using NMR spectroscopy in combination with UV, IR, and MS spectral data. Although compound 2 was previously reported as a synthetic product, we report its first isolation as a natural product. Derivative products (10-13) were obtained to test their activities against Chagas's disease. In addition, the absolute stereochemistry of the previously isolated cassane diterpene 5 from M. frutescens is presented.