title: Temporal Variation of Aristolochia chilensis Aristolochic Acids during Spring.
abstract: In this communication, we report the springtime variation of the composition of aristolochic acids (AAs) in Aristolochia chilensis leaves and stems. The dominant AA in the leaves of all samples, which were collected between October and December, was AA-I (1), and its concentration varied between 212.6±3.8 and 145.6±1.2 mg/kg and decreased linearly. This decrease occurred in parallel with the increase in AA-Ia (5) concentration from 15.9±0.8 mg/kg at the beginning of October to 96.8±7.8 mg/kg in mid-December. Both acids are enzymatically related by methylation-demethylation reactions. Other AAs also showed important variations: AA-II (2) significantly increased in concentration, reaching a maximum in the first two weeks of November and subsequently decreasing in mid-December to approximately the October levels. The principal component in the AA mixture of the stems was also AA-I (1); similar to AA-II (2), its concentration increased beginning in October, peaked in the second week of November and subsequently decreased. The concentrations of AA-IIIa (6) and AA-IVa (7) in the leaves and stems varied throughout the study period, but no clear pattern was identified. Based on the variation of AAs in A. chilensis leaves and stems during the study period, the reduced contents of non-phenolic AAs and increased concentrations of phenolic AAs are likely associated with a decrease in this plant's toxicity during the spring.
authors.affiliation: Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, Correo 33, Santiago 9170022, Chile. rocio.santanderm@usach.cl.
authors.forename: Rocío
authors.initials: R
authors.lastname: Santander
authors.affiliation: Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, Correo 33, Santiago 9170022, Chile. alejandro.urzua@usach.cl.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Urzúa
authors.affiliation: Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, Correo 33, Santiago 9170022, Chile.
authors.forename: Ángel
authors.initials: Á
authors.lastname: Olguín
authors.affiliation: Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, Correo 33, Santiago 9170022, Chile. mariapilar.sanchez@uv.cl.
authors.forename: María
authors.initials: M
authors.lastname: Sánchez
mesh_terms: D030022:Aristolochia / Q000737:chemistry*; D034341:Aristolochic Acids / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D012621:Seasons
chemical_list: D034341:Aristolochic Acids; D010936:Plant Extracts
keywords: Aristolochia chilensis; HPLC-DAD; aristolochic acids; temporal variation