As part of a continuing program to identify novel treatments for neglected parasitic diseases the Panama International Cooperative Biodiversity Group (ICBG) program has been investigating the antimalarial potential of secondary metabolites from Panamanian marine cyanobacteria. From over 60 strains of cyanobacteria evaluated in our biological screens, the organic extract of a Schizothrix species from a tropical reef near Piedras Gallinas (Caribbean coast of Panama) showed potent initial antimalarial activity against the W2 chloroquine resistant strain of Plasmodium falciparum. Bioassay guided fractionation followed by 2D NMR analysis afforded the planar structure of a new and highly functionalized linear peptide, gallinamide A. Subsequent degradation and derivatization methods were used to determine the absolute configuration at most chiral centers in this unusual new metabolite.

Background The long-distance dispersal of the invasive disease vectors Aedes aegypti and Aedes albopictus has introduced arthropod-borne viruses into new geographical regions, causing a significant medical and economic burden. The used-tire industry is an effective means of Aedes dispersal, yet studies to determine Aedes occurrence and the factors influencing their distribution along local transport networks are lacking. To assess infestation along the primary transport network of Panama we documented all existing garages that trade used tires on the highway and surveyed a subset for Ae. aegypti and Ae. albopictus . We also assess the ability of a mass spectrometry approach to classify mosquito eggs by comparing our findings to those based on traditional larval surveillance. Results Both Aedes species had a high infestation rate in garages trading used tires along the highways, providing a conduit for rapid dispersal across Panama. However, generalized linear models revealed that the presence of Ae. aegypti is associated with an increase in road density by a log-odds of 0.44 (0.73 ± 0.16; P = 0.002), while the presence of Ae. albopictus is associated with a decrease in road density by a log-odds of 0.36 (0.09 ± 0.63; P = 0.008). Identification of mosquito eggs by mass spectrometry depicted similar occurrence patterns for both Aedes species as that obtained with traditional rearing methods. Conclusions Garages trading used tires along highways should be targeted for the surveillance and control of Aedes -mosquitoes and the diseases they transmit. The identification of mosquito eggs using mass spectrometry allows for the rapid evaluation of Aedes presence, affording time and cost advantages over traditional vector surveillance; this is of importance for disease risk assessment. Electronic supplementary material The online version of this article (10.1186/s13071-019-3522-8) contains supplementary material, which is available to authorized users.

Fractionation of the crude extract of the marine cyanobacterium Lyngbya majuscule collected from Panama led to the isolation of malyngolide dimer (1). The planar structure of 1 was determined using 1D and 2D NMR spectroscopy, and HRESI-TOF MS. The absolute configuration was established by chemical degradation followed by chiral GC-MS analyses and comparisons with an authentic sample of malyngolide seco acid (4). Compound 1 showed moderate in vitro antimalarial activity against chloroquine resistant Plasmodium falciparum (W2) (IC 50 = 19 µM) but roughly equivalent toxicity against H-460 human lung cell lines. Furthermore, because the closely related cyanobacterial natural product 'tanikolide dimer' was a potent SIRT2 inhibitor, compound 1 was evaluated in this assay, but found to be essentially inactive.Malyngolide (2) and tanikolide (3) are natural δ-lactones obtained from different strains of the marine cyanobacterium Lyngbya and characterized by a hydroxymethyl group and a long aliphatic chain attached to the δ-position of a six-membered lactone ring. The main differences between compounds 2 and 3 are the presence of a secondary methyl group at C-2 of malyngolide, the number of carbons in the aliphatic chain, and perhaps most interestingly, the absolute configuration of the δ-carbon (2 = 5S; 3 = 5R). Compounds 2 and 3 were isolated from L. majuscula collected in Hawaii and Madagascar, respectively. 1,2 Malyngolide (2) displayed antibacterial activity against Mycobacterium smegmatis and Streptococcus pyogenes, while tanikolide (3) showed cytotoxicity against brine shrimp as well as antifungal and molluscicidal activity. Since malyngolide (2) was synthesized for the first time in 1980, 3 more than 66 synthetic studies have been published for this compound, and 23 for the more recently isolated tanikolide (3), providing evidence of the remarkable interest by the synthetic community in these compounds. 4 Here we report the isolation, structural determination and bioactivity of malyngolide dimer (1) from L. majuscula