Five Salts of Berberine

A new pseudopolymorph of berberine chloride: crystal structure and Hirshfeld surface analysis

The crystal structure of methanol solvate of berberine chloride, 9,10-dimeth­oxy-5,6-di­hydro-2H-7λ⁵-[1,3]dioxolo[4,5-g]iso­quinolino­[3,2-a]isoquinolin-7-ylium chloride methanol monosolvate, was determined and its Hirshfeld surface analysis was performed.

A new pseudopolymorph of berberine, 9,10-dimeth­oxy-5,6-di­hydro-2H-7λ⁵-[1,3]dioxolo[4,5-g]iso­quinolino­[3,2-a]isoquinolin-7-ylium chloride methanol monosolvate, C₂₀H₁₈NO₄⁺·Cl⁻·CH₃OH, was obtained during co-crystallization of berberine chloride with malonic acid from methanol. The berberine cations form dimers, which are further packed in stacks. The title structure was compared with other reported solvates of berberine chloride: its dihydrate, tetra­hydrate, and ethanol solvate hemihydrate. Hirshfeld analysis was performed to show the inter­molecular inter­actions in the crystal structure of the title compound, and its fingerprint plots were compared with those of the already studied solvates.

Supramolecular organisation of sulphate salt hydrates exemplified with brucine sulphate

The frequency of hydrate formation among organic sulphate salts is unravelled. Interconversion of the hydrates of brucine sulphate occurs with small changes in the relative humidity.

Five solvates of a multicomponent pharmaceutical salt formed by berberine and diclofenac

A multicomponent pharmaceutical salt formed by the isoquinoline alkaloid berberine (5,6-dihydro-9,10-dimethoxybenzo[g]-1,3-benzodioxolo[5,6-a]quinolizinium, BBR) and the nonsteroidal anti-inflammatory drug diclofenac {2-[2-(2,6-dichloroanilino)phenyl]acetic acid, DIC} was discovered. Five solvates of the pharmaceutical salt form were obtained by solid-form screening. These five multicomponent solvates are the dihydrate (BBR-DIC·2H₂O or C₂₀H₁₈NO₄⁺·C₁₄H₁₀Cl₂NO₂^-·2H₂O), the dichloromethane hemisolvate dihydrate (BBR-DIC·0.5CH₂Cl₂·2H₂O or C₂₀H₁₈NO₄⁺·C₁₄H₁₀Cl₂NO₂^-·0.5CH₂Cl₂·2H₂O), the ethanol monosolvate (BBR-DIC·C₂H₅OH or C₂₀H₁₈NO₄⁺·C₁₄H₁₀Cl₂NO₂^-·C₂H₅OH), the methanol monosolvate (BBR-DIC·CH₃OH or C₂₀H₁₈NO₄⁺·C₁₄H₁₀Cl₂NO₂^-·CH₃OH) and the methanol disolvate (BBR-DIC·2CH₃OH or C₂₀H₁₈NO₄⁺·C₁₄H₁₀Cl₂NO₂^-·2CH₃OH), and their crystal structures were determined. All five solvates of BBR-DIC (1:1 molar ratio) were crystallized from different organic solvents. Solvent molecules in a pharmaceutical salt are essential components for the formation of crystalline structures and stabilization of the crystal lattices. These solvates have strong intermolecular O...H hydrogen bonds between the DIC anions and solvent molecules. The intermolecular hydrogen-bond interactions were visualized by two-dimensional fingerprint plots. All the multicomponent solvates contained intramolecular N-H...O hydrogen bonds. Various π-π interactions dominate the packing structures of the solvates.

Crystal structure of 9,10-dimethoxy-5,6-dihydro-[1,3]dioxolo[4,5-g]isoquinolino[3,2-a]isoquinolin-7-ium chloride — 4-hydroxy-3-methoxybenzoic acid — water (2/1/5), C48H54N2Cl2O17

C48H54N2Cl2O17, orthorhombic, Pnma (no. 62), a = 28.3651(8) Å, b = 22.8464(6) Å, c = 7.1341(2) Å, V = 4623.2(2) Å3, Z = 4, Rgt(F) = 0.0437, wRref(F2) = 0.1225, T = 100(2) K.

Observation of bending, cracking and jumping phenomena on cooling and heating of tetrahydrate berberine chloride crystals

Tetrahydrate berberine chloride crystals undergo cracking, bending and jumping on cooling as well as on heating at room temperature with a rapid conversion to a dihydrate phase.

Weak C-H···X (X = O, N) hydrogen bonds in the crystal structure of dihydroberberine

Dihydroberberine (systematic name: 9,10-dimethoxy-6,8-dihydro-5H-1,3-dioxolo[4,5-g]isoquinolino[3,2-a]isoquinoline), C20H19NO4, a reduced form of pharmacologically important berberine, crystallizes from ethanol without interstitial solvent. The molecule shows a dihedral angle of 27.94 (5)° between the two arene rings at the ends of the molecule, owing to the partial saturation of the inner quinolizine ring system. Although lacking classical O-H or N-H donors, the packing in the crystalline state is clearly governed by C-H···N and C-H···O hydrogen bonds involving the two acetal-type C-H bonds of the 1,3-dioxole ring. Each dihydroberberine molecule is engaged in four hydrogen bonds with neighbouring molecules, twice as donor and twice as acceptor, thus forming a two-dimensional sheet network that lies parallel to the (100) plane.

Covalent bonding of azoles to quaternary protoberberine alkaloids

Adducts of the quaternary protoberberine alkaloids (QPA) berberine, palmatine, and coptisine were prepared with nucleophiles derived from pyrrole, pyrazole, imidazole, and 1,2,4-triazole. The products, 8-substituted 7,8-dihydroprotoberberines, were identified by mass spectrometry and 1D and 2D NMR spectroscopy, including (1)H--(15)N shift correlations at natural abundance. In addition, two adducts of QPA with chloroform and methanethiolate were characterized by using NMR data. Single-crystal X-ray structures of 8-pyrrolyl-7,8-dihydroberberine, 8-pyrazolyl-7,8-dihydroberberine, and 8-imidazolyl-7,8-dihydroberberine are also presented.

Quaternary protoberberine alkaloids

This contribution reviews some general aspects of the quaternary iminium protoberberine alkaloids. The alkaloids represent a very extensive group of secondary metabolites with diverse structures, distribution in nature, and biological effects. The quaternary protoberberine alkaloids (QPA), derived from the 5,6-dihydrodibenzo[a,g]quinolizinium system, belong to a large class of isoquinoline alkaloids. Following a general introduction, the plant sources of QPA, their biosynthesis, and procedures for their isolation are discussed. Analytical methods and spectral data are summarized with emphasis on NMR spectroscopy. The reactivity of QPA is characterized by the sensitivity of the iminium bond CN(+) to nucleophilic attack. The addition of various nucleophiles to the protoberberine skeleton is discussed. An extended discussion of the principal chemical reactivity is included since this governs interactions with biological targets. Quaternary protoberberine alkaloids and some related compounds exhibit considerable biological activities. Recently reported structural studies indicate that the QPA interact with nucleic acids predominantly as intercalators or minor groove binders. Currently, investigations in many laboratories worldwide are focused on the antibacterial and antimalarial activity, cytotoxicity, and potential genotoxicity of QPA.