Evaluation of antiparasitic,anticancer,antimicrobial and hypoglycemic properties of organic extracts from Panamanian mangrove plants

Objective: To investigate 33 organic extracts of mangrove plants for: antiparasitic, anticancer, and antibacterial activities, as well as their ability to inhibit the activity of the α-glucosidase enzyme. Methods: Leaves from all different plant mangrove species located in five mangrove zones of the Pacific coast of Panama were collected according to standard procedures. Qualitative phytochemical analysis of the organic extracts was performed by thin layer chromatography. The antiparasitic activity against Plasmodium falciparum, Trypanosoma cruzi and Leishmania donovani, toxicity against Artemia salina, anticancer activity in MCF-7 cell line, and antibacterial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa of all organic extract were investigated according protocols stablished in our institution. Finally, the ability to inhibit the enzymatic activity of α-glucosidase was evaluated by monitoring the hydrolysis of p-nitrophenyl α-Dglucopyranoside. Results: Thirty-three different samples belonging to nine different species of vascular plants with seeds of true mangroves were collected. Triterpenoids, phenolics, and tannins were the main groups of compounds found in the sampled mangroves. Saponins, quinones, and coumarins were found in less than 50%of the samples. Laguncularia racemosa showed moderate activity against Plasmodium falciparum. None of the extracts presented anticancer activity. Rhizophora mangle exhibited potent activity against Staphylococcus aureus and Bacillus subtilis [(90.41 ±7.33)% and(96.02±6.14)% of inhibition]; Avicennia germinans and Conocarpus erectus had activity against Escherichia coli[(71.17±6.15)% and(60.60±5. 13)% of inhibition,respectively]. About 60% of the mangroves showed α-glucosidase inhibitory activity. In particular, extracts from Laguncularia racemosa, Pelliciera rhizophorae, Conocarpus erectus, Mora oleifera, and Tabebuia palustris species showed α-glucosidase inhibitory potential, with IC_(50) values of(29.45±0.29),(20.60±0.70),(730.06±3.74),(25.59±0.37), and(853.39±5.30) μg/mL, respectively. Conclusions: Panamanian mangroves are mainly a promising potential source of hypoglycemic compounds, specifically α-glucosidase inhibitors.These results highlight the therapeutic virtues of extracts from American mangrove plants.

Structure modification,antialgal,antiplasmodial,and toxic evaluations of a series of new marine-derived 14-membered resorcylic acid lactone derivatives

Marine natural products play critical roles in the chemical defense of many marine organisms and are essential,reputable sources of successful drug leads.Sixty-seven 14-membered resorcylic acid lactone derivatives 3–27 and 30–71 of the natural product zeaenol(1)isolated from the marine-derived fungus Cochliobolus lunatus were semisynthesized by chlorination,acylation,esterification,and acetalization in one to three steps.The structures of these new derivatives were established by HRESIMS and NMR techniques.All the compounds(1–71)were evaluated for their antialgal and antiplasmodial activities.Among them,14 compounds displayed antifouling activities against adhesion of the fouling diatoms.In particular,9 and 34 exhibited strong and selective inhibitory effects against the diatoms Navicula laevissima and Navicula exigua(EC50=6.67 and 8.55μmol/L),respectively,which were similar in efficacy to those of the positive control SeaNine 211(EC50=2.90 and 9.74μmol/L).More importantly,38,39,and 69–71 showed potent antiplasmodial activities against Plasmodium falciparum with IC50 values ranging from 3.54 to 9.72μmol/L.Very interestingly,the five antiplasmodial derivatives displayed non-toxicity in the cytotoxicity assays and the zebrafish embryos model,thus,representing potential promising antiplasmodial drug agents.The preliminary structure–activity relationships indicated that biphenyl substituent at C-2,acetonide at positions C-5′and C-6′,and tri-or tetra-substituted of acyl groups increased the antiplasmodial activity.Therefore,combining evaluation of chemical ecology with pharmacological models will be implemented as a systematic strategy,not only for environmentally friendly antifoulants but also for structurally novel drugs.