Boesenbergia rotunda (L.) cyclohexenyl chalcone derivatives, 4-hydroxypanduratin A and panduratin A, showed good competitive inhibitory activities towards dengue 2 virus NS3 protease with the Ki values of 21 and 25 microM, respectively, whilst those of pinostrobin and cardamonin were observed to be non-competitive. NMR and GCMS spectroscopic data formed the basis of assignment of structures of ...

The mol-ecule of the title heteroaryl chalcone derivative, C13H11NOS, exists in a trans-configuaration and is almost planar with a dihedral angle of 3.73 (8)° between the phenyl and thio-phene rings. An intra-molecular N-H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, two adjacent mol-ecules are linked into a dimer in an anti-parallel face-to-face manner by a pair of C-H⋯O inter...

Chalcone/flavanone interconversion occurs facilely under aqueous alkaline conditions making it a promising scaffold for the development of a covalent molecular switch. In this study, a single methoxy substituent is shown to have a significant impact on the equilibrium dynamics of this reaction; this impact is dependent on the site of substitution.

In the title chalcone derivative, C(15)H(9)Cl(3)O, the dihedral angle between the 2-chloro-phenyl and 2,4-dichloro-phenyl rings is 41.79 (14)°. Weak C-H⋯O and C-H⋯Cl intra-molecular inter-actions involving the enone unit generate S(5) ring motifs. In the crystal structure, the mol-ecules are arranged in a head-to-tail manner along the a axis. These chains are stacked along the b axis.

The effect of aryl substitution on various aspects of the interconversion of ortho-hydroxychalcones and flavanones has been studied using multiple spectroscopic techniques. Derivatization of the core scaffold predictably alters the midpoint pH of this equilibration process suggesting its viability for application as a functional colorimetric molecular switch.

Two new flavanones and one chalcone were isolated from the peel of Citrus kinokuni Hort. ex Tanaka and identified as (2S)-5,6,7,8,4'-pentamethoxyflavanone (1), (2S)-5,6,7,3',4'-pentamethoxyflavanone (2) and 2'-hydroxy-3,4,3',4',6'-pentamethoxychalcone (3). The structures of new compounds were elucidated by spectroscopic analysis.

Highly enantioselective aziridination of chalcones catalyzed by a novel backbone 1,8-bisoxazolidinylanthracene (AnBOX) and CuOTf with up to >99% ee and the opposite enantioselectivity compared with the ligands of Evans are described.

In the chalcone title compound, C(18)H(17)BrO(4), the dihedral angle between the mean planes of the 2-bromo- and 3,4,5-trimethoxy-substituted benzene rings is 89.3 (1)°. The angles between the mean plane of the prop-2-en-1-one group and the 2-bromo-phenyl and 3,4,5-trimeth-oxy-phenyl ring planes are 59.7 (1) and 40.5 (8)°, respectively. While no classical hydrogen bonds are present, three weak ...

In the title chalcone derivative, C(20)H(22)O(6), the dihedral angle between the mean planes of the benzene rings is 15.77 (6)°. The H atoms of the central C=C double bond are in a trans configuration. There are a number of C-H⋯O interactions and a C-H⋯π interaction present in the crystal structure.

The asymmetric unit of the title chalcone derivative, C(19)H(20)ClNO, contains two independent mol-ecules, which differ in the conformations of the ethyl groups in the diethyl-amino substituents. In the crystal, weak inter-molecular C-H⋯O hydrogen bonds link mol-ecules into ribbons propogating in [010]. The crystal packing also exhibits weak C-H⋯π inter-actions.