title: Raman spectroscopy study of calcium oxalate extracted from cacti stems.
abstract: To find markers that distinguish the different Cactaceae species, by using near infrared Raman spectroscopy and scanning electron microscopy, we studied the occurrence, in the stem, of solid deposits in five Cactaceae species (Coryphantha clavata, Ferocactus latispinus, Opuntia ficus-indica, O. robusta, and O. strepthacantha) collected from their natural habitats from a region of México. The deposits in the tissues usually occurred as spheroidal aggregates, druses, or prismatic crystals. From the Raman spectra, the crystals were identified either as calcium oxalate monohydrate (CaC2O4·H2O) or calcium oxalate dihydrate (CaC2O4·2H2O). Opuntia species (subfamily Opuntioideae) showed the presence of CaC2O4·H2O, and the deposition of CaC2O4·2H2O was present in C. clavata and F. latispinus (subfamily Cactoideae, Cacteae tribe). As a punctual technique, Raman spectroscopy seems to be a useful tool to identify crystal composition. In addition to allowing the analysis of crystal morphology, this spectroscopic technique can be used to identify Cactaceae species and their chemotaxonomy.
authors.affiliation: Centro de Investigaciones en Óptica, A.C., Unidad Aguascalientes, Prol. Constitución 607, Fracc. Reserva Loma Bonita,Aguascalientes, 20200 México.
authors.forename: Claudio
authors.initials: C
authors.lastname: Frausto-Reyes
authors.forename: Sofia
authors.initials: S
authors.lastname: Loza-Cornejo
authors.forename: Teresa
authors.initials: T
authors.lastname: Terrazas
authors.forename: Tania
authors.initials: T
authors.lastname: Terrazas
authors.forename: María de la Luz
authors.initials: Mde L
authors.lastname: Miranda-Beltrán
authors.forename: Xóchitl
authors.initials: X
authors.lastname: Aparicio-Fernández
authors.forename: Brenda M
authors.initials: BM
authors.lastname: López-Macías
authors.forename: Sandra E
authors.initials: SE
authors.lastname: Morales-Martínez
authors.forename: Martín
authors.initials: M
authors.lastname: Ortiz-Morales
mesh_terms: D029421:Cactaceae / Q000737:chemistry*; D002129:Calcium Oxalate / Q000737:chemistry*; D018547:Plant Stems / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D002129:Calcium Oxalate