Chiroptical studies on brevianamide B: vibrational and electronic circular dichroism confronted.
Chiroptical spectroscopies, such as electronic circular dichroism (ECD) and vibrational circular dichroism (VCD), are highly sensitive techniques to probe molecular conformation, configuration, solvation, and aggregation. Here we report the application of these techniques to study the fungal metabolite brevianamide B. Comparison of the experimental ECD and VCD spectra with the density functional theory simulated counterparts establishes that VCD is the more reliable technique to assign absolute configuration due to the larger functional and dispersion dependence of computed ECD spectra. Despite a low amount of available material and a relatively unusual example of using VCD carbonyl multiplets, the absolute configuration could be reliably predicted, strengthening the case for application of VCD in the study of complex natural products. Spectral and crystallographic evidence for or against the formation of a dimeric aggregate is discussed; in solution, the VCD spectra strongly suggest only monomeric species are present.
†Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281 S3, B9000 Ghent, Belgium.|‡European Centre for Chirality, Krijgslaan 281 S3, B9000 Ghent, Belgium.
Patrick
P
Bultinck
§Department of Chemistry, Imperial College London South Kensington Campus, London SW7 2AZ, United Kingdom.
Fanny L
FL
Cherblanc
§Department of Chemistry, Imperial College London South Kensington Campus, London SW7 2AZ, United Kingdom.
Matthew J
MJ
Fuchter
‡European Centre for Chirality, Krijgslaan 281 S3, B9000 Ghent, Belgium.|∥Department of Chemistry, University of Antwerp Groenenborgerlaan 171, 2020 Antwerp, Belgium.
Wouter A
WA
Herrebout
§Department of Chemistry, Imperial College London South Kensington Campus, London SW7 2AZ, United Kingdom.
Ya-Pei
YP
Lo
§Department of Chemistry, Imperial College London South Kensington Campus, London SW7 2AZ, United Kingdom.
Henry S
HS
Rzepa
⊥Diamond Light Source, Chilton, Oxon OX11 0QX, United Kingdom.
Giuliano
G
Siligardi
§Department of Chemistry, Imperial College London South Kensington Campus, London SW7 2AZ, United Kingdom.
Marko
M
Weimar
D000470:Alkaloids / Q000737:chemistry*; D002942:Circular Dichroism; D008968:Molecular Conformation; D015394:Molecular Structure; D010879:Piperazines / Q000737:chemistry*; D013141:Spiro Compounds / Q000737:chemistry*; D013237:Stereoisomerism; D014732:Vibration
D000470:Alkaloids; D010879:Piperazines; D013141:Spiro Compounds; C116214:brevianamide B