title: Epimeric Excolides from the Stems of Excoecaria agallocha and Structural Revision of Rhizophorin A.
abstract: Excolides A-B (1-4) represent the first examples of a new class of secolabdanoids with an unprecedented framework, which were isolated from the stems of Excoecaria agallocha. Their structures were determined by spectroscopic analysis, chemical modifications, CD, and single-crystal X-ray analysis (1 and 4) as excolide A (1), 11-epi-excolide A (2), 11,13-di-epi-excolide A (3), and excolide B (4). In addition, the structure of rhizophorin A (7), a novel bicyclic secolabdanoid, was revised as excolide A (1).
authors.affiliation: †Natural Products Chemistry Division, Indian Institute of Chemical Technology, Hyderabad, India.
authors.forename: S Ch V Appa Rao
authors.initials: SCh
authors.lastname: Annam
authors.affiliation: †Natural Products Chemistry Division, Indian Institute of Chemical Technology, Hyderabad, India.
authors.forename: Madhu
authors.initials: M
authors.lastname: Ankireddy
authors.affiliation: †Natural Products Chemistry Division, Indian Institute of Chemical Technology, Hyderabad, India.
authors.forename: Madhu Babu
authors.initials: MB
authors.lastname: Sura
authors.affiliation: †Natural Products Chemistry Division, Indian Institute of Chemical Technology, Hyderabad, India.
authors.forename: Mangala Gowri
authors.initials: MG
authors.lastname: Ponnapalli
authors.affiliation: ‡NMR Division, Indian Institute of Chemical Technology, Hyderabad, India, 500 607.
authors.forename: Akella V S
authors.initials: AV
authors.lastname: Sarma
authors.affiliation: ‡NMR Division, Indian Institute of Chemical Technology, Hyderabad, India, 500 607.
authors.forename: Jeelani Basha
authors.initials: JB
authors.lastname: S
mesh_terms: D004224:Diterpenes / Q000138:chemical synthesis* / Q000737:chemistry* / Q000302:isolation & purification; D019665:Euphorbiaceae / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure
chemical_list: D004224:Diterpenes; C000602035:excolide A; C000602036:excolide B; C438451:rhizophorin A