The PBE0/pcSseg-2//pcseg-2 calculations of 1H and 13C NMR chemical shifts were performed for a classical series of 12 Strychnos alkaloids (except for the earlier studied parent strychnine), namely akuammicine, isostrychnine, rosibiline, tsilanine, spermostrychnine, diaboline, cyclostrychnine, henningsamide, strychnosilidine, strychnobrasiline, holstiine, and icajine. It was found that calculated 1H and 13C NMR chemical shifts demonstrated markedly good correlations with available experimental data characterized by a mean absolute error of 0.22 ppm for the range of 8 ppm for protons and 1.97 ppm for the range of 180 ppm for carbons. Complimentary, present results provide essential NMR update and fill a gap in the NMR data of this distinguished group of the vitally important natural products.
1H and 13C NMR, DFT, strychnos alkaloids.
1. S. P. A. Sauer, Molecular Electromagnetism. A Computational Chemistry Approach, University Press,
2. T. Helgaker, M. Jaszuński, K. Ruud, Chem. Rev. 1999, 99, 293-352.
3. T. Helgaker, M. Jaszuński, M. Pecul, Prog. NMR Spectrosc. 2008, 53, 249-268.
4. T. Helgaker, S. Coriani, P. Jørgensen, K. Kristensen, J. Olsen, K. Ruud, Chem. Rev. 2012, 112, 543
5. R. H. Contreras, M. B. Ferraro, M. C. Ruiz de Azúa, G. A. Aucar, in High Resolution
6. Y. Y. Rusakov, L. B. Krivdin, Russ. Chem. Rev. 2013, 82, 99-130.
7. I. L. Rusakova, Y. Y. Rusakov, L. B. Krivdin, Russ. Chem. Rev. 2016, 85, 356-426.
8. F. A. A. Mulder, M. Filatov, Chem. Soc. Rev. 2010, 39, 578-590.
9. L. B. Krivdin, Prog. NMR Spectrosc. 2017, 102-103, 98-119.
10. L. B. Krivdin, Prog. NMR Spectrosc. 2018, 105, 54-99.
11. L. B. Krivdin, Prog. NMR Spectrosc. 2018, 108, 17-73.
12. L. B. Krivdin, Prog. NMR Spectrosc. 2019, 112-113, 103-156.
13. V. A. Semenov, L. B. Krivdin, Magn. Reson. Chem. 2020, 58, 56-64.
14. W. He, P. Wang, J. Chen, W. Xie, Org. Biomol. Chem. 2020, 18, 1046-1056.
15. A. Cherif, G. E. Martin, L. R. Soltero, G. Massio, J. Nat. Prod. 1990, 53, 793- 802.
