In the title compound, C16H9ClO4, the dihedral angle between the coumarin ring system [maximum deviation = 0.023 (1) Å] and the benzene ring is 73.95 (8)°.

In the title compound, C16H9FO4, the dihedral angle between the planar coumarin ring system [maximum deviation = 0.027 (1) Å] and the benzene ring is 70.18 (6)°. In the crystal, π–π interactions [shortest centroid–centroid separation = 3.5338 (8) Å] link the molecules into a three-dimensional framework.

In the title coumarin derivative, C20H18O4, the benzene ring of the benzoate group is oriented at a dihedral angle of 57.55 (9)° with respect to the planar chromene ring system [maximum deviation from plane is 0.027 (2) Å]. In the crystal, inversion-related molecules are linked into dimers via C—H...O hydrogen bonds, generating R 2 2(12) loops. The dimers are linked by further C—H...O hydrogen bonds forming layers, parallel to the bc plane, which are linked via C—H...π interactions, forming a three-dimensional framework

In the title compound, C 16 H 10 O 4 , the dihedral angle between the coumarin ring system (r.m.s. deviation = 0.015 Å ) and the benzoate group is 83.58 (9) , which compares to a value of 81.8 obtained from a DFT calculation at the B3LYP/6-311 G(d,p) level. In the crystal, C-OÁ Á Á and C-HÁ Á Á interactions and aromatic -[CgÁ Á ÁCg = 3.7214 (14) and 3.7059 (14) Å ] stacking generate a three-dimensional network. Structure descriptionCoumarin-based ion receptors, fluorescent probes, and biological stains have extensive applications in monitoring enzyme activity as well as accurate pharmacological and pharmacokinetic properties in living cells (Chen et al., 2013;Guha et al., 2012). As part of our ongoing studies in this area, we now present herein the synthesis and structure of the title compound (Fig. 1).As expected, the coumarin ring system is almost planar, the maximum deviation from the plane of 0.022 (2) Å is for atom C9. The torsion angles C10-C8-O4-C7 [107.8 (2) ], C8-O4-C7-C6 [À170.95 (15) ] and O4-C7-C6-C1 [176.48 (15) ] are typical of the torsional freedom permitted by the rotation of the benzoate group at position 3. The greatest conformational freedom of the molecule resides, therefore, in the benzoate bridge of compound, composed by C8-O4-C7-C6.In the crystal, there are C-HÁ Á Á and C-OÁ Á Á contacts present (Table 1 and Fig. 2) and also --stacking interactions. The HÁ Á Á and OÁ Á Á separations are comparable with those cited by Imai et al. (2008) from a database analysis, which concluded that such interactions were attractive, with interaction energies of ca 2 kcal mol À1 , comparable to those typical of weak hydrogen bonds. These interactions result in the formation of zigzag

Mental disorders or illnesses are common and affect all countries. According to official estimates, in most countries at least one person in three is affected. Several researches have shown the benefits of plants in the management of these pathologies. This study focuses on five medicinal plants useful in the management of mental disorders, including Cymbopogon citratus, Lippia chevalieri, Combretum micratum, Chrysantellum americanum and Tetrapleura tetraptera. These plants are used in Burkina Faso in the form of herbal teas. The objective of this study is to enhance the value of these plants and improve their use by some physico-chemical analyses, a phytochemical study and the determination of antioxidant activity. Among the parameters that will be precisely investigated there are organoleptic analysis, moisture content, extraction yields, thin layer chromatographic fingerprinting, phytochemical screening and the determination of total phenol, total flavonoids. The DPPH method was used to evaluate the antioxidant power of the various aqueous extracts. The physico-chemical analysis gave satisfactory results on the main indices. The phytochemical study allowed to establish the chromatographic fingerprints of the aqueous extracts, to identify the main bioactive secondary metabolites and to determine the content of total phenols and total flavonoids in the extracts of the five plants. Interesting results are obtained, which confirms the use of these plants. Among the samples submitted to the different analyses, the extract of Combretum micratum presented high levels of total phenolics (395,38 ± 7,05 mg GAE/g extract) and total flavonoids (105,87 ± 0,05 mg Ru E/g extract). This extract also exhibited the highest antiradical activity.