title: Bis-spirolabdane diterpenoids from Leonotis nepetaefolia.
abstract: Ten new bis-spirolabdane diterpenoids, leonepetaefolins A-E (1, 3, 5, 7, 9) and 15-epi-leonepetaefolins A-E (2, 4, 6, 8, 10), together with eight known labdane diterpenoids (11-18) as well as two known flavonoids, apigenin and cirsiliol, were isolated from the leaves of Leonotis nepetaefolia. The structures of the new compounds were determined on the basis of 1D- and 2D-NMR experiments including (1)H, (13)C, DEPT, (1)H-(1)H COSY, HSQC, HMBC, and NOESY. The absolute configuration of an epimeric mixture of 1 and 2 was determined by X-ray crystallographic analysis. The compounds isolated were evaluated for their binding propensity in several CNS G-protein-coupled receptor assays in vitro.
authors.affiliation: Department of Pharmacognosy, School of Pharmacy, University of Mississippi, University, Mississippi 38677-1848, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Frank R
authors.initials: FR
authors.lastname: Fronczek
authors.forename: Daneel
authors.initials: D
authors.lastname: Ferreira
authors.forename: Charles L
authors.initials: CL
authors.lastname: Burandt
authors.forename: Vincent
authors.initials: V
authors.lastname: Setola
authors.forename: Bryan L
authors.initials: BL
authors.lastname: Roth
authors.forename: Jordan K
authors.initials: JK
authors.lastname: Zjawiony
mesh_terms: D018360:Crystallography, X-Ray; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D019686:Lamiaceae / Q000737:chemistry*; D008968:Molecular Conformation; D015394:Molecular Structure; D009419:Nerve Tissue Proteins / Q000187:drug effects*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010568:Peru; D018515:Plant Leaves / Q000737:chemistry; D043562:Receptors, G-Protein-Coupled / Q000187:drug effects*
chemical_list: D004224:Diterpenes; D009419:Nerve Tissue Proteins; D043562:Receptors, G-Protein-Coupled; C433017:labdane