Conformational analysis of guaianolide-type sesquiterpene lactones by low-temperature NMR spectroscopy and semiempirical calculations
Само за регистроване кориснике
2004
Аутори
Milosavljević, SlobodanJuranić, Ivan
Bulatovic, V
Macura, Slobodan
Juranić, Nenad
Limbach, HH
Weisz, K
Vajs, Vlatka
Todorović, Nina
Чланак у часопису (Објављена верзија)
Метаподаци
Приказ свих података о документуАпстракт
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.
Кључне речи:
guaianolides / cumambrine / conformations / low-temperature NMR / dynamic NMR / PM3 semiempirical calculationsИзвор:
Structural Chemistry, 2004, 15, 3, 237-245Издавач:
- Kluwer Academic/Plenum Publ, New York
DOI: 10.1023/B:STUC.0000021533.65546.57
ISSN: 1040-0400
WoS: 000220454200009
Scopus: 2-s2.0-3543112180
Институција/група
IHTMTY - 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 . .