Planta Med 2015; 81 - PW_151
DOI: 10.1055/s-0035-1565775

Stereochemical study of natural products by electronic circular dichroism

A Mándi 1, S Antus 1, P Proksch 2, BG Wang 3, T Kurtán 1
  • 1Department of Organic Chemistry University of Debrecen, P.O. Box 20, 4010-Debrecen, Debrecen, Hungary
  • 2Institut für Pharmazeutische Biologie und Biotechnologie, Heinrich-Heine-Universität, Universitätsstrasse 1, D-40225 Düsseldorf, Germany
  • 3Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Nanhai Road 7, Qingdao 266071, China

The axial chirality of biaryl natural products with restricted rotation along the biaryl axis or the preferred helicity of biaryls with low rotational energy barrier is a stereochemical feature, which can affect the bioactivity of xanthone biaryl natural products profoundly. The applicability of electronic circular dichroism (ECD) method supported with TDDFT-ECD calculation was demonstrated on the stereochemical study of biaryl xanthone natural products such as the axially chiral neosartorin (1) [1] and dicerandrol B (2) [2] having free rotation along the biaryl axis.

The absolute configuration of the chirality centers and preferred solution conformations were determined by TDDFT-ECD calculations for conformationally flexible natural products such as 13-hydroxy-dihydroresorcylide (3) [3] and brocaeloid A (4) [4], and for the bridged O,N-heterocycle varioxepine A (5) [5].

References:

[1] Ola ARB, Debbab A, Aly AH, Mándi A, Zerfass I, Hamacher A, Kassack MU, Brötz-Oesterhelt H, Kurtán T, Proksch P. Tetrahedron Lett 2014; 55: 1020 – 1023

[2] Rönsberg D, Debbab A, Mándi A, Vasylyeva V, Böhler P, Stork B, Engelke L, Hamacher A, Sawadogo R, Diederich M, Wray V, Lin W-H, Kassack MU, Janiak C, Scheu S, Wesselborg S, Kurtán T, Aly AH, Proksch P. J Org Chem. 2013; 78: 12409 – 12425

[3] Zhang P, Meng L-H, Mándi A, Kurtán T, Li X-M, Li C-S, Liu Y, Li X, Wang B-G. RSC Advances. 2015; 5: 39870 – 39877

[4] Zhang P, Meng L-H, Mándi A, Kurtán T, Li X-M, Liu Y, Li X, Li C-S, Wang B-G. Eur J Org Chem. 2014; 4029 – 4036

[5] Zhang P, Mándi A, Li X-M, Du F-Y, Wang J-N, Li X, Kurtán T, Wang B-G. Org Lett 2014; 16: 4834 – 4837