title: Calyculaglycosides D and E, novel cembrane glycosides from the Caribbean gorgonian octocoral Eunicea species and structural revision of the aglycon of calyculaglycosides A-C.
abstract: A recent investigation of the constituents of Eunicea sp. from Colombia and Puerto Rico has provided two novel cembrane glycosides, calyculaglycosides D (6) and E (7), and a new cembranoid diterpene in free form, (+)-nephthenol (4). Metabolites 6 and 7 possess a glycosyl-fused cembrane skeleton with a 1S configuration. Biogenetic considerations have led to a revision of the previously assigned dilophol skeleton of calyculaglycosides A-C, which was confirmed by extensive 2D NMR investigation and a chemical degradation study. Consequently, the true structures for calyculaglycosides A-C are 8-10, respectively, not 1-3. This is the first report of the occurrence of marine diterpene glycosides having a cembrane aglycon.
authors.affiliation: Department of Chemistry, University of Puerto Rico, P.O. Box 23346, San Juan, Puerto Rico 00931-3346, USA.
authors.forename: Y P
authors.initials: YP
authors.lastname: Shi
authors.forename: A D
authors.initials: AD
authors.lastname: Rodríguez
authors.forename: O L
authors.initials: OL
authors.lastname: Padilla
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D003063:Cnidaria / Q000737:chemistry*; D003105:Colombia; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D008401:Gas Chromatography-Mass Spectrometry; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D011647:Puerto Rico; D013055:Spectrophotometry, Infrared; D013237:Stereoisomerism
chemical_list: D004224:Diterpenes; D006027:Glycosides; C442769:calyculaglycoside D; C442770:calyculaglycoside E; C037071:cembrane