Background: the emergence of bacterial resistance has led to a search for new natural products as alternatives starting points to prevent and control diseases caused by microorganisms. Among the potential candidates were bioactive compounds from octocorals of the genus Eunicea due to their chemical structures and their wide range of biological activities. Objective: the purpose of this study was to evaluate the quorum sensing inhibition (QSI) and antibacterial activity of compounds previously isolated from two Eunicea species and synthesized alkylglycerols (AKG). Methods: the QSI of three nonpolar compounds and a mixture of AKGs from Eunicea were evaluated by a microtiter plate assay using Chromobacterium violaceum (ATCC 31532). Four naturally occurring, saturated, and enantiomerically pure AKGs, all of which were derived from the chiral precursor (R)-solketal, were synthesized from alkyl chains of 12, 14, 16 and 18 carbons, and their structures were spectroscopically verified by NMR, ESI-MS and optical rotation data. Their QSI by the disc diffusion assay and minimum inhibitory concentrations (MIC) against 14 clinical bacterial isolates in microtiter plates were determined. Results: cembradiene 1, the AKG mixture and AKG (2S)-3-O-dodecyl-1,2-propanediol 4 inhibit QS at the same concentration as kojic acid (10 µg/well or 20 µg/disc, respectively). In this study, the bioactive compounds 1, stearyl oleate 2, acylglycerol 3 and AKGs 4 and (2S)-3-O-tetradecyl-1,2-propanediol 5 showed in vitro IQS activity for the first time. Additionally, 4 and 5 displayed in vitro antibacterial activity against Listeria innocua and Staphylococcus aureus (MIC = 32 µg/mL for both 4 and 5), Enterococcus faecalis (128 µg/mL and 64 µg/mL respectively), Micrococcus luteus (128 µg/mL for both) and Brevibacillus brevis (Bacillus brevis) (512 µg/mL and 64 µg/mL respectively). Conclusion: results suggest that natural compounds 1, 2, 3, 4 and 5 showed QSI, also 4 and 5 have antibacterial activity and they are an interesting alternative to continue researching their effect against pathogenic microorganisms.
Remote sensors permit forecasting the nutrient status and yields in crops of economic importance in Colombia. The objective of this study was to determine the relationships between normalized difference vegetation index (NDVI) and yield as well as concentrations of ${\rm {N - NO}}_3^ - $ and K+ in stem sap of potato cultivars Diacol Capiro and Pastusa Suprema (Solanum tuberosum L., Group Andigenum) in relation to different fertilizer rates. Increasing doses (0, 1450, 1900 and 2375 kg ha–1) of macro- and micronutrient fertilizers were applied to determine NDVI behavior at 55, 75, 100, 125 and 150 days after planting. For Capiro, significant differences in NDVI readings (0.84–0.88) were found between phenological stages. In both cultivars, NDVI correlated positively with yield and K+ concentrations in stem sap during tuber filling and maturation, while in Capiro no correlation was established between NDVI values and ${\rm {N - NO}}_3^ - $ concentrations in stem sap. The NDVI readings could be used to forecast productivity and K status in potato Group Andigenum.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.