TY  - JOUR
AU  - Milosavljević, Slobodan
AU  - Juranić, Ivan
AU  - Bulatovic, V
AU  - Macura, Slobodan
AU  - Juranić, Nenad
AU  - Limbach, HH
AU  - Weisz, K
AU  - Vajs, Vlatka
AU  - Todorović, Nina
PY  - 2004
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2731
AB  - Conformational analysis of 9alpha-acetoxycumambrine A 1 and 8-O-isobutiryl-9alpha-acetoxycumambrine B 2 was carried out by low-temperature NMR studies. Results suggested that lactones 1 and 2 are mixtures of two distinctive conformers, I and II. Based on low-temperature H-1 NMR spectra, in four solvents, the thermodynamic parameters of I reversible arrow II exchange process were assessed. Energy of activation of I -- gt  II reaction was obtained by dynamic NMR simulations for both compounds. Results revealed that conformational exchange of lactones 1 and 2 occurs due to "chair reversible arrow twisted chair" interconversion of a heptane ring. The same PM3 semiempirical method was applied for geometry optimization of lactones 1 and 2, as well as of 9alpha-hydroxycumambrine A 3, 9alpha-acetoxycumambrine B 4, and cumambrine B 5.
PB  - Kluwer Academic/Plenum Publ, New York
T2  - Structural Chemistry
T1  - Conformational analysis of guaianolide-type sesquiterpene lactones by low-temperature NMR spectroscopy and semiempirical calculations
VL  - 15
IS  - 3
SP  - 237
EP  - 245
DO  - 10.1023/B:STUC.0000021533.65546.57
ER  - 

@article{
author = "Milosavljević, Slobodan and Juranić, Ivan and Bulatovic, V and Macura, Slobodan and Juranić, Nenad and Limbach, HH and Weisz, K and Vajs, Vlatka and Todorović, Nina",
year = "2004",
abstract = "Conformational analysis of 9alpha-acetoxycumambrine A 1 and 8-O-isobutiryl-9alpha-acetoxycumambrine B 2 was carried out by low-temperature NMR studies. Results suggested that lactones 1 and 2 are mixtures of two distinctive conformers, I and II. Based on low-temperature H-1 NMR spectra, in four solvents, the thermodynamic parameters of I reversible arrow II exchange process were assessed. Energy of activation of I -- gt  II reaction was obtained by dynamic NMR simulations for both compounds. Results revealed that conformational exchange of lactones 1 and 2 occurs due to "chair reversible arrow twisted chair" interconversion of a heptane ring. The same PM3 semiempirical method was applied for geometry optimization of lactones 1 and 2, as well as of 9alpha-hydroxycumambrine A 3, 9alpha-acetoxycumambrine B 4, and cumambrine B 5.",
publisher = "Kluwer Academic/Plenum Publ, New York",
journal = "Structural Chemistry",
title = "Conformational analysis of guaianolide-type sesquiterpene lactones by low-temperature NMR spectroscopy and semiempirical calculations",
volume = "15",
number = "3",
pages = "237-245",
doi = "10.1023/B:STUC.0000021533.65546.57"
}

Milosavljević, S., Juranić, I., Bulatovic, V., Macura, S., Juranić, N., Limbach, H., Weisz, K., Vajs, V.,& Todorović, N.. (2004). Conformational analysis of guaianolide-type sesquiterpene lactones by low-temperature NMR spectroscopy and semiempirical calculations. in Structural Chemistry
Kluwer Academic/Plenum Publ, New York., 15(3), 237-245.
https://doi.org/10.1023/B:STUC.0000021533.65546.57

Milosavljević S, Juranić I, Bulatovic V, Macura S, Juranić N, Limbach H, Weisz K, Vajs V, Todorović N. Conformational analysis of guaianolide-type sesquiterpene lactones by low-temperature NMR spectroscopy and semiempirical calculations. in Structural Chemistry. 2004;15(3):237-245.
doi:10.1023/B:STUC.0000021533.65546.57 .

Milosavljević, Slobodan, Juranić, Ivan, Bulatovic, V, Macura, Slobodan, Juranić, Nenad, Limbach, HH, Weisz, K, Vajs, Vlatka, Todorović, Nina, "Conformational analysis of guaianolide-type sesquiterpene lactones by low-temperature NMR spectroscopy and semiempirical calculations" in Structural Chemistry, 15, no. 3 (2004):237-245,
https://doi.org/10.1023/B:STUC.0000021533.65546.57 . .