Conformational Mobility Study in Mono Quinone Derivative of Calix[4]arene by Low Temperature NMR Spectroscopy

: Calix[4]monoquinone (3) has been synthesized by oxidation of rigid cone conformation of tripropoxy calix[4]arene (2), and conformational characteristics of this molecule have been studied by means of dynamic nuclear magnetic resonance (DNMR) and HH- correlated nuclear magnetic resonance spectroscopy (HH-COSY NMR). On the basis of the data that have been obtained, free Gibbs energy of activation (ΔG#) for quinone ring interconversion process of 3 was determined 12.3±0.05 Kcal/mol by coalescence approximation method.

Host–guest complexation of ionic liquid with α- and β-cyclodextrins: a comparative study by 1H-NMR, 13C-NMR and COSY

The inclusion complexation of 1-butyl-3-methylimidazolium octylsulphate [Bmim][OS] with host α- and β-cyclodextrins (CDs) has been explored by 1H NMR, 13C NMR and COSY methods. The insertion of a guest molecule into the cavity of CD is clearly reflected by changes in 1H-NMR and 13C-NMR chemical shift values and COSY NMR suggest that both H-bonding and electrostatic interactions involved to the complexation.

Бүтэн навчит хонлэн (lagotis integrifolia schischk)- гоос ялгасан диосметиний бүтцийн судалгаа

Lagotis integrifolia (Willd.) Schischk is an ingredient of the many traditional prescriptions andused for the treatment of fever, blood disorder, vitals disorder, diphtheria, anthrax, and pneumonia in Mongolian traditional medicine. A compound was isolated by column chromatography and HPLC methods. Molecular structures of them were elucidated by MS, 1H, 13С, HSQC, HMBC and 1Н-1Н COSY NMR method. We purified and identified as 7-dihydroxy-2-(3-hydroxy-4-methoxyphenyl) chromen-4-one (diosmetin) from the aerial parts of Lagotis integrifolia (Willd.)Schischk. Diosmetin has been obtained from this species for the first time