Three undescribed coumarin derivatives, pituranthosin A–C (1-3), along with nineteen known compounds were isolated and identified from the chloroform ethyl acetate fractions of hydroalcoholic extract Deverra battandieri (Apiaceae). The structures established by interpretation their spectral data using 1D-NMR (1H, 13C, DEPT experiments), 2D-NMR (COSY, NOESY, HSQC HMBC), HRESIMS, comparison liter...

Small molecules are central to biology, mediating critical phenomena such as metabolism, signal transduction, mating attraction, and chemical defense. The traditional categories that define small molecules, such as metabolite, secondary metabolite, pheromone, hormone, and so forth, often overlap, and a single compound can appear under more than one functional heading. Therefore, we favor a unif...

The rate of hydrogen bond formation at individual amino acid residues in ribonuclease T1 (RNase T1) has been investigated by the hydrogen-deuterium exchange-2D NMR (HDEx-2D NMR) technique (Udgaonkar & Baldwin, 1988; Rder et al., 1988) to gain insight into the mechanism and pathways of protein folding. The HDEx-2D NMR technique combines rapid mixing and 2D NMR methods to follow the protection of...

Solution NMR spectroscopy represents a powerful tool for examining the structure and function of biological macromolecules. The advent of multidimensional (2D-4D) NMR, together with the widespread use of uniform isotopic labeling of proteins and RNA with the NMR-active isotopes, 15N and 13C, opened the door to detailed analyses of macromolecular structure, dynamics, and interactions of smaller ...

Indirect detection of 13C and 15N nuclear magnetic resonance (NMR) spectra through 1H NMR signals offers large sensitivity advantages in studies of organic and biological molecules in solution and is almost universally employed.1-3 Although sensitivity enhancement by indirect detection was first demonstrated in NMR4-6 and nuclear quadrupole resonance7,8 of solids, direct detection has generally...

Tanaproget is a first-in-class nonsteroidal progesterone receptor agonist that is being investigated for use in contraception. A major in vitro and in vivo metabolite of tanaproget formed in humans was initially characterized as a glucuronide of tanaproget. However, whether the glucuronide was linked to the nitrogen or sulfur of the benzoxazine-2-thione group in tanaproget could not be determin...

We have recently demonstrated that the spatial encoding of internal nuclear magnetic resonance (NMR) spin interactions can be exploited to collect multidimensional NMR spectra within a single scan. Such experiments rely on an inhomogeneous spatial excitation of the spins throughout the sample, and lead to indirect-domain peaks via a constructive interference among the spatially resolved spin-pa...

Spectral reconstruction from multi-component spectroscopic data is the frequent primary goal in chemical system identification and exploratory chemometric studies. Various methods and techniques have been reported in the literature. However, few algorithms/methods have been devised for spectroscopy recovery without the use of any a priori information. In the present studies, a higher dimensiona...

Surfactant protein B (SP-B) is a 79-residue essential component of lung surfactant, the film of lipid and protein lining the alveoli, and is the subject of great interest for its role in lung surfactant replacement therapies. Here we report circular dichroism results and the solution NMR structure of SP-B(11-25) (CRALIKRIQAMIPKG) dissolved in CD(3)OH at 5 degrees C. This is the first report of ...