Potential applications of 2D relaxation spectrum NMR and MRI to characterize complex water dynamics (e.g., compartmental exchange) in biology and other disciplines have increased in recent years. However, the large amount of data and long MR acquisition times required for conventional 2D MR relaxometry limits its applicability for in vivo preclinical and clinical MRI. We present a new MR pipeli...

We report herein a feasible study concerning syntheses and structure of some diazolium salts with dihydroxyacetophenone skeleton of anticipated anticancer activity. A fast, general and facile method for preparation of 1,3-diazol salts via N-alkylation reactions under conventional heating and microwave irradiation is presented. The microwaves remarkably accelerated these N-alkylations, the react...

A new scheme for the excitation of spins according to the joint values of their heteronuclear or homonuclear J couplings and of their chemical shifts, is proposed and demonstrated. The principles of the new pulses involved derive from those employed in NMR imaging for exciting arbitrary 2D spatial shapes, using so-called "multidimensional" RF pulses. It is shown that if recast in a suitable spe...

A baseline correction routine that eliminates dispersive tails extending from the water tr noise band in 2D NMR spectra has been developed. Streaks along the w2 axis (Fig. la) spreading from the w2 position of the water resonance are among the most perturbing artifacts in 2D NMR spectra where the water signal is reduced by presaturation. In our experience, these streaks have dispersive lineshap...

Among the methods proposed in recent years toward the acceleration of multidimensional NMR acquisitions is an "ultrafast" approach, capable of delivering arbitrary 2D correlations within a single scan. This scheme operates by parallelizing the indirect-domain temporal incrementation involved in 2D acquisitions, using as aid an ancillary inhomogeneous frequency broadening acting in combination w...

Achillea tenuifolia Lam (Asteraceae) afforded a methanolic extract from which after fractionation in solvents with different polarities two known flavones 3’, 5- dihydroxy- 4’, 6, 7- trimethoxy flavone (eupatorine, compound 3), 5- hydroxy- 3’, 4’, 6, 7- tetramethoxyflavone (compound 4), besides stearic acid (compound 1 ), lupeol (compound 2), daucosterol (β- sitosterol 3-O- β- D- glucopyranosid...

Achillea tenuifolia Lam (Asteraceae) afforded a methanolic extract from which after fractionation in solvents with different polarities two known flavones 3’, 5- dihydroxy- 4’, 6, 7- trimethoxy flavone (eupatorine, compound 3), 5- hydroxy- 3’, 4’, 6, 7- tetramethoxyflavone (compound 4), besides stearic acid (compound 1 ), lupeol (compound 2), daucosterol (β- sitosterol 3-O- β- D- glucopyranosid...

In the last five decades study on plant secondary metabolites have been increasing. Higher plants with a wide range of secondary metabolites have been very important in the search of new therapeutic agents. Flavonoids are most widely distributed secondary natural metabolites that found in plants which occuring in free forms or as glycosides with polyphenolic structure. In this study secondary m...

We describe several homo- and heteronuclear 2D NMR strategies dedicated to the analysis of anisotropic (2)H spectra of a mixture of dideuterated unlike/like stereoisomers with two remote stereogenic centers, using weakly orienting chiral liquid crystals. To this end, we propose various 2D correlation experiments, denoted "D(H)(n)D" or "D(H)(n)C" (with n=1, 2), that involve two heteronuclear pol...