The title compound C13H12N4OS (I) is synthetized from isonicotinic hydrazide and isothiocynate. Compounds C13H11N4OCl (II) and C13H10N4S (III) where obtained upon reaction of (I) with Fe(II) or Mn(II) salts. Compound (II) is heterocyclic 1,3,4-oxadiazole while compound (III) is heterocyclic 1,2,4-triazole. The 1,3,4-oxadiazol derivative is almost planar with dihedral angle of 2.66 (8) and 5.14 (8)° between 1,3,4-oxadiazole ring and phenyl and pyridinium rings respectively; the dihedral angle between the phenyl and pyridinium rings is 3.92 (8)°. The 1,2,4-triazole derivative is non-planar. The phenyl and pyridyl rings form dihedral angles of 58.35 (5) and 58.33 (5)°, respectively, with the 1,2,4-triazole ring; the dihedral angle between the phenyl and pyridyl rings is 36.85 (4)°. In the compound (II) intramolecular hydrogen bonds of type N—H···Cl, C—H···N and C—H···Cl resulting in S(6) ring stabilize the structure. Intermolecular hydrogen bonds of type N—H···N, C—H···N, C—4···Cl link the molecule thus forming a three-dimensional network. In the structure of compound (III), intermolecular hydrogen bonds of type N—H···N, C—H···N, C—H···S1,link the monomer in a three-dimensional network.

Mots clés : Naphtopyranone, Guiera senegalensis, analyse par fluorescence, lumière UV. Study of the Fluorescent properties of a naphtopyranone isolated fromGuiera senegalensis ABSTRACT Guiera senegalensis is a plant used in therapeutic in Senegal and in several countries of West Africa. This justifies the development of photochemical methods of analysis of the isolated fluorescent naphtopyranone of this plant. Thus, these types of compounds could be analyzed from biological fluids and facilitate the pharmacological study. The influence of pH and several solvents of different polarity on the fluorescence intensity, the excitation and emission of naphtopyranone spectra were studied. This study allowed to draw calibration lines of the naphthopyranone, which leads to a calibration line strongly correlated. All analytical parameters that result were calculated. The results of irradiation were used to determine rate constant (k = 4,85.10 -2 min -1 ), half-life (t 1/2 =14,3 min), and order 1 of the kinetic of photodegradation. The low values of the limit of detection (LOD = 27 μg/mL) and quantification (LOQ = 250 μg/mL) shows a good sensitivity of this method of analysis and its possible application as a technique for qualitative and quantitative detection of these types of compounds in urine or blood.

Reputed to be a plant rich in antioxidants, Abelmoschus esculentus or okra is a very effective vegetable against diabetes. In this work, we made a qualitative study of the bioactive compounds contained in the leaves and seeds of okra, through a phytochemical screening. Subsequently, the antioxidant and antimicrobial activities of these extracts were studied. The Folin-Ciocalteu reagent was used to evaluate the content of the phenolic compound. The DPPH● radical made it possible to measure the antioxidant power of the extracts. The phytochemical analysis made it possible to high the presence of substances with great therapeutic values ​​(polyphenols, flavonoids, tannins, alkaloids, etc.). The antibacterial activity was measured on bacterial strains. The antioxidant capacities reveal that the extracts of the leaves and seeds of okra possess an interesting anti-free radical activity with IC50 values ​​of 06 ± 0.21 mg / mL and 8.85 ± 0.28 mg / mL respectively for the leaves and the seeds. . Biological analysis shows that the E. faecalis strain is resistant to different extracts. E. coli, S. aureus, and P. aeruginosa strains show some sensitivity to ethanolic extracts. However, E. colis and S. aureus strains show the best antimicrobial activities with a MIC of 3.75 mg/mL for crude ethanol extract and ethanol fraction of leaves and seeds.

Gardenia ternifolia is a medicinal plant used in Senegal and in several African countries for the treatment of many pathologies. According to the results of the bibliography, the four parts of the plant, mainly used for medicinal purposes, are recommended. Therefore, the chemical studies made on the extracts of the leaves, roots, seeds and fruits show that they are rich sources of secondary metabolites. The phytochemical study carried out on the hexane, ethyl acetate, methanolic and aqueous extracts of the leaves and stem bark of the Gardenia ternifolia plant reveals the presence of polyphenols, flavonoids, alkaloids, gallic and catechin tannins, sterols, polyterpenes, coumarins, mucilages, catechols and Leucoanthocyanins in the two different organs of this plant. The successive extracts obtained with hexane, ethyl acetate, methanol and water gave yields varying respectively from 0.14 to 3.94% for the four leaves extracts and 0.08 to 1.62% for the four stem bark extracts. The determination of the total polyphenols of the methanolic extracts respectively gave variable contents between 1.57 ± 0.05 and 7.00 ± 0.044 μg EAG/mg for the leaves and the bark of the stems. Compared to flavonoids, the levels vary respectively between 1.57 ± 0.05 and 15.45 ± 0.066 μg EQ/mg for stem bark and leaves. In general, the methanolic extract and the aqueous extract are the richest in secondary metabolites, polyphenols and flavonoids. This suggests that these families of compounds are responsible for the biological activity of the plant in the treatment of certain types of diseases. However, in-depth tests on the antioxidant, antidiabetic and antimicrobial activities are necessary in order to identify the full therapeutic potential of this plant.

One new γ-hydroxybutenolide (1) together with the known compounds (2-7) were isolated from the Senegalese marine sponge Luffariella geometrica. Their chemical structures were established on the basis of spectroscopic methods 1D and 2D NMR, in addition to mass spectrometry and comparison with literature data.