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We present the determination of the conformational properties ofaeroplysinin-1 in aqueous solution by means of a combined experimentaland theoretical Raman optical activity (ROA) and vibrational circulardichroism (VCD) study. Aeroplysinin-1 is an antiangiogenic drug extractedfrom the sponge Aplysina cavernicolawhich has beenproved to be a valuable candidate for the treatment of cancer andother antiangiogenic diseases. Our study shows that this moleculepossesses the 1S,6Rabsolute configurationin aqueous solution, where only two conformers are present to a significantlevel. We discuss in detail the relationships between the chiro-opticalROA and VCD features, and the structural properties of various energyaccessible conformers are described. The present work is one of thefirst studies in which both ROA and VCD have been used as complementarytools for the determination of absolute configuration and dominantsolution-state conformations of an unknown therapeutically significantmolecule. [ABSTRACT FROM AUTHOR]

An analysis is performed on the molecular and electronic features in a series of trigonal molecules constituted by a central truxene core which is ramified with three oligofluorene moieties of different lengths. Arms and core are studied independently and upon threefold unification. Special emphasis is paid to the modulation of the conjugational properties in relation to substitution, molecular dimension, ring aromaticity, intermolecular forces, oxidation state, etc. Raman and optical absorption/emission spectroscopies in conjunction with computational theoretical results are combined for this purpose. The evolution of some key intensity ratios in the Raman spectra (i.e., I1300/I1235) is followed as an indication of electronic interaction between the core and the branches. The changes of the electronic delocalization upon solvation, with varying temperature in the solid state, with the nature of the aromatic unit (bithiophene/fluorene) or after electrochemical oxidation are interpreted. The modulation of the optical properties on the basis of the structure and energetics of the orbital around the gap is also addressed. Density functional theory was used to assign the vibrational and electronic spectra. [ABSTRACT FROM AUTHOR]