4',5-Dihy-droxy-7-meth-oxy-flavanone dihydrate

Area of Science:

• Natural Products Chemistry
• Crystallography
• Phytochemistry

Background:

• Heliotropium taltalense, a native Chilean plant, produces natural phytoalexins.
• Flavonoids, like the title compound, are a significant class of plant secondary metabolites.
• Understanding the solid-state structure of natural compounds is crucial for their characterization.

Purpose of the Study:

• To elucidate the crystal structure of 5-hydroxy-2-(4-hydroxyphenyl)-7-methoxy-chroman-4-one dihydrate.
• To analyze the intermolecular interactions and conformation of the hydrated flavone.
• To compare the molecular geometry with its previously reported anhydrous form.

Main Methods:

• Single-crystal X-ray diffraction was used to determine the crystal structure.
• Analysis of hydrogen bonding networks (intra- and intermolecular).
• Conformational analysis of the chromanone and phenyl rings.

Main Results:

• The asymmetric unit contains one molecule of 5-hydroxy-2-(4-hydroxyphenyl)-7-methoxy-chroman-4-one and two water molecules.
• A strong intramolecular hydrogen bond exists between the 5-hydroxy group and the carbonyl group.
• A three-dimensional network is formed through O-H⋯O hydrogen bonds in the crystal lattice.
• The pyrone ring exhibits a slightly distorted sofa conformation.

Conclusions:

• The crystal structure of the hydrated flavone was successfully determined.
• The compound forms an extensive hydrogen-bonded network in the solid state.
• The hydrated form shows minimal geometric differences compared to the anhydrous structure.