An insight on the alkaloid content of Capparis spinosa L. root by HPLC-DAD-MS, MS/MS and (1)H qNMR.

The Capparis spinosa L. has a wide distribution in the Old World from South Europe, North and East Africa, Madagascar, Southwest and Central Asia to Australia and Oceania. The consolidated traditional use of C. spinosa root as remedy against different pains in human is well known since the antiquity. Various secondary metabolites have been found in caper plant, nevertheless, few studies have been focused to the analysis of root constituents. To date, several free and glycosilated spermidine alkaloids and a more polar alkaloid, the stachydrine, have been isolated from the root of C. spinosa. Aim of this work was to improve the knowledge on the alkaloid content of the root of a Syrian sample of C. spinosa by HPLC-DAD-MS(n) and to propose methods to quantify these molecules in different raw extracts. A decoction, an hydroalcoholic extraction and a fractionation process to selectively recover the spermidine alkaloids were applied. To our knowledge, this is the first HPLC-DAD-MS(n) profile that pointed out the co-presence of stachydrine, several isobaric forms of capparispine and/or capparisine in free and glycosylated forms and some isobars of isocodonocarpine or codonocarpine as monoglycosides in extracts of C. spinosa root. The determination by HPLC/DAD for the spermidine alkaloids expressed as p-OH-coumaric acid gave values up to 3.5mg/g dried root and the stachydrine evaluated by (1)H NMR was close to 12.5mg/g dried root. Overall, the total alkaloids were almost doubled in hydroalcoholic extract with respect to the decoction, and the stachydrine in the cortex was almost double than in the whole root.

Pyrazolo[1,5-a]quinazoline scaffold as 5-deaza analogue of pyrazolo[5,1-c][1,2,4]benzotriazine system: synthesis of new derivatives, biological activity on GABAA receptor subtype and molecular dynamic study.

To investigate the binding affinity of GABAA receptor subtype, new pyrazolo [1,5-a]quinazolines were designed, synthesized, and in vitro evaluated. These compounds, 5-deaza analogues of pyrazolo[5,1-c][1,2,4]benzotriazine derivatives which were already studied in our research group, permit us to evaluate the relevance of the nitrogen or the oxygen atom at 5-position of the tricyclic scaffold. Molecular dynamic study was done on a set of the new and known ligands to rationalize and to explain the lack of affinity on the 4- or 5-substituted new derivative. In fact, from biological results, it can be found that the only 5-unsubstituted new derivative, compound 15, has receptor recognition (Ki = 834.7 nM).