Crystal structure, Hirshfeld surface analysis and electrostatic potential study of naturally occurring cassane-type diterpenoid Pulcherrimin C monohydrate at 100 K

The title cassane-type diterpenoid known as pulcherrimin C, C34H36O8 center dot H2O, systematic name 5,6-bis(benzoyloxy)-4a-hydroxy-4,7,11b-trimethy-11,2,3,4,4a,5,6,6a,7,11,11a,11b-dodecahydrophenanthro[3,2-b]furan-4-carboxylic acid monohydrate, was isolated as a monohydrate from the medicinally important plant Caesalpinia pulcherrima, found in the tropical regions of south and south-east Asia. The molecule is composed of three trans-fused six-membered rings having chair, chair and half-chair conformations, and a five-membered planar furan ring. In the crystal, O-H center dot center dot center dot O hydrogen bonds link molecules into chains parallel to the b axis. Weak C-H center dot center dot center dot pi interactions are also observed. Hirshfeld surface analysis indicates that the contribution of O center dot center dot center dot H interactions towards the total generated Hirshfeld surface is 21.5%.