1.Sedative effect of monoterpene alcohols in mice: a preliminary screening.
de Sousa DP1, Raphael E, Brocksom U, Brocksom TJ. Z Naturforsch C. 2007 Jul-Aug;62(7-8):563-6.
Many essential oils and monoterpenes are used therapeutically as relaxing drugs and tranquilizers. In this study, ten structurally related monoterpene alcohols, present in many essential oils, were evaluated in mice to investigate their pharmacological potential in the central nervous system. Isopulegol (1), neoisopulegol (2), (+/-)-isopinocampheol (3), (-)-myrtenol (4), (-)-cis-myrtanol (5), (+)-p-menth-1-en-9-ol (6) and (+/-)-neomenthol (8) exhibited a depressant effect in the pentobarbital-induced sleep test, indicating a sedative property. (-)-Menthol (7), (+)-dihydrocarveol (9), and (+/-)-isoborneol (10) were ineffective in this test. The results show that these psychoactive monoterpenes have the profile of sedative drugs, and this pharmacological effect is influenced by the structural characteristics of the molecules.
2.Fast access to residual dipolar couplings by single-scan 2D NMR in oriented media.
Giraudeau P1, Montag T, Charrier B, Thiele CM. Magn Reson Chem. 2012 Dec;50 Suppl 1:S53-7. doi: 10.1002/mrc.3856. Epub 2012 Aug 5.
Residual dipolar couplings (RDCs) have revolutionized the structure determination of biomolecular and organic compounds. So far, their measurement has been rather time-consuming, but one might imagine that RDCs can one day also be useful in the investigation of compounds with limited stability or short lifetimes. For such applications, it is indispensable to shorten the experiment time. In this communication, we show the first measurement of RDCs from single-scan two-dimensional NMR. An ultrafast HSQC NMR pulse sequence is presented, which includes several of the recent improvements brought to ultrafast NMR in terms of sensitivity, resolution, and spectral width. Ultrafast spectra are obtained in as little time as 60 s on an organic compound at natural abundance, namely (+)-isopinocampheol. When extracting the RDCs from these ultrafast data, a good agreement with those extracted from conventional spectra (obtained in a much longer time) is observed.
3.How different are diastereomorphous orientations of enantiomers in the liquid crystalline phases of PBLG and PBDG: a case study.
Marx A1, Schmidts V, Thiele CM. Magn Reson Chem. 2009 Sep;47(9):734-40. doi: 10.1002/mrc.2454.
The orientational properties of the two enantiomers of an example compound, namely isopinocampheol [(+)- and (-)-IPC] in the two enantiomers of a liquid crystalline phase, namely Poly-gamma-benzyl-L/D-glutamate (PBLG/PBDG) with the organic cosolvent CDCl(3), were investigated. The interactions can be either enantiomorphous, leading to equal orientations and residual dipolar couplings (RDCs), or diastereomorphous, leading to different orientations and RDCs. The difference between the two diastereomorphous orientations was determined to be rather small (5 degrees in the Euler angle beta). Furthermore, we investigated whether one of the two diastereomorphous interactions is favored.