Cembranoid diterpenes from the Caribbean sea whip Eunicea knighti.
Three new cembranoid diterpenes, knightol (1), knightol acetate (2), and knightal (3), along with the known asperdiol (4) and asperdiol acetate (5), were isolated as major compounds from the sea whip Eunicea knighti collected from the Colombian Caribbean. The structures and absolute configurations of 1-5 were determined on the basis of spectroscopic analyses and by a combination of chemical and NMR methods, multiple correlations observed in a ROESY experiment, and using the modified Mosher method. Additionally, five semisynthetic compounds, 6-10, obtained during the chemical transformations of the natural compounds are here reported for the first time. All compounds were tested for antimicrobial activity against marine bacteria associated with heavily fouled surfaces and were also screened for antiquorum sensing (QS) activity. Compounds 1, 3, and 8 showed significant antimicrobial activity against bacterial isolates, and 1, 3, 7, and 8 showed excellent anti-QS inhibition activity measured by means of bioluminescence inhibition with biosensor model systems.
Tello
Edisson
E
Departamento de Quimica, Universidad Nacional de Colombia, Bogota, Colombia.
Castellanos
Leonardo
L
Arevalo-Ferro
Catalina
C
Duque
Carmenza
C
D000818:Animals; D037421:Anthozoa / Q000737:chemistry*; D017691:Caribbean Region; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D013237:Stereoisomerism
D004224:Diterpenes; C544279:knightal; C544278:knightol; C544280:knightol acetate