title: Hobartine: a tetracyclic indole alkaloid extracted from Aristotelia chilensis (maqui).
abstract: The natural compound hobartine {systematic name: (1R)-3-[(1S,5S)-(4,4,8-trimethylbicyclo[3.3.1]non-7-en-2-yl)methyl]-2,3-dihydro-1H-indole}, C20H26N2, (I), is an indole alkaloid isolated from Aristotelia chilensis as part of a study of secondary metabolites from Chilean flora. The colourless compound has a tetracyclic structure closely related to the strongly coloured polymorphic structures discussed in Paz et al. [Acta Cryst. (2013), C69, 1509-1512] and Watson et al. [Acta Cryst. (1989), C45, 1322-1324]. The main differences reside in the absence of a keto group in (I) compared with the previous structures, as well as an endo double bond in (I) contrasting with the exo double bond found in the previous structures. The supramolecular structure of (I) in strongly related to the twofold screw axis, around which isolated chains build up, internally linked by an N-H···N hydrogen bond which is the only significant intermolecular interaction present in the structure.
authors.affiliation: Departamento de Ciencias Químicas y Recursos Naturales, Facultad de Ingeniería, Universidad de La Frontera, Temuco, Chile.
authors.forename: Cristian
authors.initials: C
authors.lastname: Paz Robles
authors.affiliation: Departamento de Ciencias Químicas y Recursos Naturales, Facultad de Ingeniería, Universidad de La Frontera, Temuco, Chile.
authors.forename: Natalia
authors.initials: N
authors.lastname: Badilla Vidal
authors.affiliation: Departamento de Química Inorgánica, Analítica y Química, Física/INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Sebastián
authors.initials: S
authors.lastname: Suarez
authors.affiliation: Gerencia de Investigación y Aplicaciones, Centro Atómico Constituyentes, Comisión Nacional de Energía Atómica, Buenos Aires, Argentina.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Baggio
mesh_terms: D001688:Biological Products / Q000138:chemical synthesis / Q000737:chemistry* / Q000302:isolation & purification*; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D026121:Indole Alkaloids / Q000138:chemical synthesis / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D015394:Molecular Structure
chemical_list: D001688:Biological Products; D026121:Indole Alkaloids; C000596814:hobartine
keywords: Aristotelia chilensis; Chilean flora metabolites; alkaloid; crystal structure; hobartine; maqui; natural products; tetracyclic compound