Resolution and absolute configuration assignment of a natural racemic chromane from Peperomia obtusifolia (Piperaceae).
The resolution of the natural racemic chromane 3,4-dihydro-5-hydroxy-2,7-dimethyl-8-(3''-methyl-2''-butenyl)-2-(4'-methyl-1',3'-pentadienyl)-2H-1-benzopyran-6-carboxylic acid (1) isolated from the leaves of Peperomia obtusifolia has been accomplished using stereoselective HPLC. The absolute configuration of the resolved enantiomers was determined by the analysis of optical rotations and CD spectra. The finding of a racemic mixture instead of an enantiomerically pure metabolite raises questions about the final steps in the biosynthesis of this class of natural products, suggesting that the intramolecular chromane ring formation step may not be enzymatically controlled at all in P. obtusifolia.
Batista
João Marcos
JM
Nucleus for Bioassays, Biosynthesis and Ecophysiology of Natural Products, Organic Chemistry Department, Institute of Chemistry, São Paulo State University, Araraquara, SP, Brazil.
López
Silvia Noelí
SN
Mota
Jonas da Silva
Jda S
Vanzolini
Kenia Lourenço
KL
Cass
Quezia Bezerra
QB
Rinaldo
Daniel
D
Vilegas
Wagner
W
Bolzani
Vanderlan da Silva
Vda S
Kato
Massuo Jorge
MJ
Furlan
Maysa
M
D001578:Benzopyrans / Q000737:chemistry* / Q000302:isolation & purification; D001688:Biological Products / Q000737:chemistry* / Q000302:isolation & purification; D002839:Chromans / Q000737:chemistry* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D009904:Optical Rotation; D036941:Peperomia / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry; D013237:Stereoisomerism
C545838:3,4-dihydro-5-hydroxy-2,7-dimethyl-8-(3''-methyl-2''-butenyl)-2-(4'-methyl-1',3'-pentadienyl)-2H-1-benzopyran-6-carboxylic acid; D001578:Benzopyrans; D001688:Biological Products; D002839:Chromans