Complete assignment of the 1H and 13C NMR spectra of garciniaphenone and keto-enol equilibrium statements for prenylated benzophenones.
This article reports the structural elucidation by IR, UV and MS spectroscopic data along with 1H and 13C NMR chemical shift assignments of two benzophenones isolated from the fruit pericarp of Garcinia brasiliensis Mart. (Clusiaceae): garciniaphenone, (1R,5S,7S)-3-benzoyl-4-hydroxy-6,6-dimethyl-5,7-di(3-methyl-2-butenyl)bicyclo[3.3.1]non-3-ene-2,9-dione, a novel triprenylated benzophenone; and 7-epi-clusianone, a tetraprenylated benzophenone that has already been extracted from another species of the same family. Furthermore, the keto-enol tautomeric equilibrium at solution-state was described for these compounds by 1D and 2D NMR spectral methods and one attempt to rationalize the different ratios between the noted tautomers was based on stereochemical features.
Derogis
Priscilla B M C
PB
Departamento de Farmácia, Universidade Federal de Alfenas-UNIFAL-MG, Rua Gabriel Monteiro da Silva 714, CEP 37130-000, Alfenas, MG, Brazil.
Martins
Felipe T
FT
de Souza
Thiago C
TC
de C Moreira
Maria E
ME
Souza Filho
José D
JD
Doriguetto
Antonio C
AC
de Souza
Kamila R D
KR
Veloso
Marcia P
MP
Dos Santos
Marcelo H
MH
D001577:Benzophenones / Q000737:chemistry* / Q000302:isolation & purification; D016227:Benzoquinones; D001643:Bridged Bicyclo Compounds / Q000737:chemistry* / Q000302:isolation & purification; D002247:Carbon Isotopes; D005638:Fruit / Q000737:chemistry; D029760:Garcinia / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods / Q000592:standards*; D008968:Molecular Conformation; D054876:Prenylation; D011522:Protons; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism
C118110:7-epiclusianone; D001577:Benzophenones; D016227:Benzoquinones; D001643:Bridged Bicyclo Compounds; D002247:Carbon Isotopes; D011522:Protons; C528023:garciniaphenone