title: A new norkaurane-gamma-lactone from Parinari sprucei.
abstract: The title tetracyclic diterpenoid, 10,13,16,17-tetrahydroxy-9-methyl-15-oxo-20-norkaurane-18,10-carbolactone hemihydrate, C(20)H(28)O(6).0.5H(2)O, is a plant metabolite from Parinari sprucei, part of the Venezuelan Amazon flora. The asymmetric unit consists of two nearly identical molecules of the diterpenoid and one molecule of water. Some of the geometric parameters reflect steric strain in the molecule. The extended structure is characterized by hydrogen bonds and weaker hydrogen-mediated interactions, which involve all of the hydroxy groups and propagate in sheets that coincide with the (002) family of planes. The water molecule acts as a double hydrogen-bond donor and single acceptor and thus plays a critical role in the pattern of intermolecular interactions.
authors: Dipartimento di Scienze Farmaceutiche, Università di Salerno, Via Ponte Don Melillo, I-84084 Fisciano, Salerno, Italy. mattia@unisa.it
authors: Carlo Andrea
authors: CA
authors: Mattia
authors: Alessandra
authors: A
authors: Braca
authors: Nunziatina
authors: N
authors: De Tommasi
authors: Raffaella
authors: R
authors: Puliti
mesh_terms: D018360:Crystallography, X-Ray; D004224:Diterpenes / Q000737:chemistry*; D045786:Diterpenes, Kaurane; D006860:Hydrogen Bonding; D007783:Lactones / Q000737:chemistry*; D019684:Magnoliopsida / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure
chemical_list: C495463:10,13,16,17-tetrahydroxy-9-methyl-15-oxo-20-norkaurane-18,10-carbolactone; D004224:Diterpenes; D045786:Diterpenes, Kaurane; D007783:Lactones