Supplementary Materialsmarinedrugs-17-00111-s001

Supplementary Materialsmarinedrugs-17-00111-s001. ingredient in antifouling coatings. sp. LEGE 05292 through the Blue Biotechnology and Ecotoxicology Culture Collection (LEGE CC, http://www.ciimar.up.pt/legecc/), based on their allelopathic effect on the Sevelamer hydrochloride microalga [25]. Portoamides A and B in natural mixtures also showed synergistic allelophatic activity towards other co-occuring microalgae (and larvae, and their potential marine ecotoxicity was also evaluated. In this study, this multi-bioassay approach will allow for determination of whether portoamides Sevelamer hydrochloride are effective as broad-spectrum and eco-friendly AF compounds and if they follow the new guidelines for the discovery of clean natural AF agents. 2. Results and Discussion 2.1. Mytilus galloprovincialis Larvae Antisettlement Activity and Recovery Portoamides demonstrated a highly significant activity towards the settlement of the mussel plantigrades larvae for all the concentrations tested ( 0.01) when compared to the negative control, resulting in a complete inhibition of the larval settlement at a concentration of 32 M, and an 50% response concentration (EC50) value of 3.16 M/4.86 gmL?1 (Figure 1). Open in a separate window Figure 1 DoseCresponse antisettlement activity of portoamides towards plantigrade larvae of the mussel B: DMSO control (0.01%); C: 5 M CuSO4 as the positive control. This antisettlement bioactivity is highly relevant as it is well below the reference value for EC50 ( 25 gmL?1) established by the U.S. Navy program for suitable AF compounds. Sevelamer hydrochloride This EC50 value is lower than that of some previous AF compounds isolated from marine organisms [27,28,29], and their effectiveness is within the concentration range of synthetic nature inspired AF compounds tested in the same experimental conditions using plantigrades antisettlement responses [30,31]. Considering pure compounds isolated from cyanobacterial strains and tested for antisettlement activity, portoamides are more effective than hantupeptin C (EC50 = 10.6 gmL?1), but less potent than isomalyngamide A (EC50 = 2.6 gmL?1), majusculamide A (EC50 = 0.54 gmL?1), and dolastatin 16 (EC50 = 0.003 gmL?1), all isolated from the cyanobacterium [32]. However, these compounds were only tested against cyprids and larval sensitivity among invertebrate species could be specific. Additionally, dolastatin 16 is quite powerful against COL12A1 cyprids arrangement, but poisonous at low concentrations (LC50 = 20 gmL also?1). The same was discovered for the substance Maculalactone A isolated through the cyanobacterium larvae [33]. The portoamides degree of effectiveness towards larvae is greater than that of the commercial agent ECONEA also?, that includes a reported EC50 worth of 4.01 M [30]. Regardless of the high performance in avoiding plantigrades arrangement, portoamides triggered no mortality to the prospective species at the concentrations examined, as the industrial AF agent ECONEA? was found out to exert some toxicity (LC50 = 107.89 MmL?1) [31]. Having less toxicity of portoamides towards mussel larvae in the examined concentrations shows that portoamides have a deterring effect rather than a toxic mechanism towards the mussel larvae. In addition, the settlement recovery bioassay pointed out that after a recovery period of 15 h in fresh seawater, larval settlement responses increased by 35% and 45%, when compared to the responses immediately after portoamides exposure (3 M and 16 M, respectively), being also not significantly different from the negative control (Figure 2). This might indicate that the mechanisms involved in larval antisettlement are reversible at least after acute exposure to portoamides. Open in a separate window Figure 2 Settlement response of plantigrade larvae of the mussel after 15 h of exposure to portoamides followed by 15 h of recovery in filtered seawater. B: DMSO control (0.01%); C: 5 M Sevelamer hydrochloride CuSO4 as the positive control. This implies that portoamides have a potential to be employed as environmentally friendly AF agents against mussel attachment prevention, which is environmentally relevant, as sp. are one of most prevalent macrofouling organisms worldwide, representing a significant part of the biofouling biomass [34,35]. 2.2. Antibacterial and Antimicroalgal Activities The capacity of portoamides to interfere with microfouling growth was assessed by screening portoamides against a panel of marine bacteria and microalgae species involved in marine biofilm formation. In total, portoamide bioactivity was tested against five marine bacteria and four microalgae strains. The results showed significant activity of portoamides against three of the tested marine bacteria, (inhibition of 23.3%), (inhibition of 21.0%) and (inhibition of 21.5%) at a concentration of 6.5 M, but no significant inhibitory activity against or was detected. In the doseCresponse.