Reinvestigation of the proton resonance spectrum of vindolinine at 300 MHz.
نویسندگان
چکیده
A reinvestigation of the proton resonance spectrum of vindolinine based on new data at 300 MHz is now completely consistent with the recently modified structure. These data are presented as an example of possible pitfalls in the interpretation of complex spectral data for structural analysis. Spectra and assignments are included.
منابع مشابه
Investigation of the H Spin-Lattice Relaxation in Polycrystalline NH4Re04 Induced by Mechanical Sample Rotation
Measurements of the proton spin-lattice relaxation time, Tx , in polycrystalline NH4Re04 have shown that mechanical sample rotation in the static magnetic field reduces 2\ for proton magnetic resonance frequencies within the range 30 — 42 MHz. The rotation induced proton spin-lattice relaxation times, ?Y, were measured at different Larmor frequencies, sample rotation frequencies, and temperatur...
متن کاملDesigning and Fabrication of a New Radiofrequency Planar microcoil for mini-Nuclear Magnetic Resonance
Introduction Radiofrequency planar microcoils are used to increase the resolution of magnetic resonance images of small samples. In this study, we aimed to design and fabricate a spiral planar microcoil constructed on a double-sided printed circuit board (PCB). It has four rings with an internal diameter of 241 microns tuned and matched at 63.8 MHz. Materials and Methods To achieve the maximum ...
متن کاملHigh-resolution proton nuclear magnetic resonance studies of human gastrin.
High-resolution 1H nuclear magnetic resonance (NMR) spectroscopy at 300 MHz has been used to study the behavior of human gastrin in aqueous solution. A large number of resonances have been assigned by analysis of one- and two-dimensional NMR spectra and the effects of pH and by comparison with the spectrum of des-less than Glu1-gastrin. In gastrin, the ratio of cis to trans conformations around...
متن کاملMRS Shimming: An Important Point Which Should not be Ignored
Introduction: Proton magnetic resonance spectroscopy (MRS) is a well-known device for analyzing the biological fluids metabolically. Obtaining accurate and reliable information via MRS needs a homogeneous magnetic field in order to provide well-defined peaks and uniform water suppression. There are lots of reasons which can disturb the magnetic field homogeneity which can be corrected by a proc...
متن کاملAPPLICATION OF ULTRASONIC RESONANCE TECHNIQUE AT 300 MHz TO THE DETECTION OF DISBONDS IN
This paper describes the results of work on the feasibility of using high frequency ultrasound to determine .the degree of bondedness of multilayer structures. A sandwich structure of two identical metal sheets of thickness on the order of 25 ~m, bonded together by a dissimilar third layer of thickness 10 ~m was examined. The primary disbond was expected to be in the region of the interface bet...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 71 10 شماره
صفحات -
تاریخ انتشار 1974