GIAO DFT 13C/15N chemical shifts in regioisomeric structure determination of fused pyrazoles.

The combined use of two-dimensional NMR correlation experiments and gauge including atomic orbital density functional theory in (13)C NMR chemical shift (CS) calculations allowed reliable and simple structural determination of regioisomeric heterocyclic systems that originate from the reactions of acylquinolinones with substituted hydrazines. Moreover, the results of differential analysis between the calculated (15)N NMR CSs for hypothetical structures and the experimental data of the title azaheterocyclic systems were even more advantageous with respect to (13)C because there was no need for correlational analysis: structures of the regioisomeric compounds could be determined just by direct comparison.

Microwave-assisted reaction of glycosylamine with aspartic acid.

The synthesis of N-protected glycosyl amino acids from amines has been investigated and it was found that, under microwave conditions, glycosylamines could be hydrolyzed leading to new products containing a glycosyl ester linkage. The efficiency of the microwave-induced glycosylation of aspartic acid was studied comparing the microwave activity between amide and ester bond formation. Different sugar moieties have been employed to demonstrate the simple and reproducible coupling methodology.

Synthesis and biological evaluation of new geiparvarin derivatives.

New geiparvarin derivatives modified at the unsaturated alkenyloxy bridge, where a hydrogen atom replaces the 3'-methyl group, were synthesized and evaluated against a panel of human tumor cell lines in vitro. These compounds demonstrated an increase in growth inhibitory activity relative to the parent compound, geiparvarin. The activity increased even further in the series of demethylated compounds, with the introduction of a methyl group at the 1'-position of the alkenyloxy chain.

On the reactivity of 6-acetyl-7-(2-dimethylaminovinyl)pyrazolo[1,5-a]pyrimidines with 1,3- and 1,4-bisnucleophiles.

Reaction of 6-acetyl-7-(2-dimethylaminovinyl)pyrazolo[1,5-a]pyrimidine 1 with 1,3- and 1,4-bisnucleophiles has been investigated; obtainment of new polycyclic heterocyclic derivatives is reported. A convenient procedure leading to new pyrazolo[1,5-a]quinazolines is described; a modest bioactivity of these compounds against two human tumor cell lines was also ascertained.

Synthesis, cytotoxicity, and apoptosis induction in human tumor cells by geiparvarin analogues.

A series of geiparvarin analogues modified on the unsaturated alkenyloxy bridge, where a H-atom replaced the 3'-Me group, were synthesized and evaluated against a panel of human tumor cell lines in vitro. These compounds demonstrated a stronger increase in growth inhibitory activity when compared to the parent compound geiparvarin (8). In particular, the activity increased even further in the series of demethylated compounds when a Me substituent in the coumarin moiety is introduced.