RESUMEN
Procedure for isolation of pyrrolizidine alkaloids (PAs) from Rindera umbellata Bunge plant species was optimised. Different extraction media (methanol, ethanol and sulphuric acid), concentration and volume of sulphuric acid, pH of PA solution for alkaline extraction, extraction time and techniques (maceration, ultrasonic and overhead rotary mixer assisted extraction) were investigated. The yields of six PAs (7-angeloyl heliotridane, 7-angeloyl heliotridine, lindelofine, 7-angeloyl rinderine, punctanecine and heliosupine) were monitored by GC-MS/FID. The best results for the isolation all of six PAs were obtained when the extraction was performed with 1 M sulphuric acid (30 mL per 1.00 g of dried sample) by overhead rotary mixer during three days. Optimal pH value for alkaline extraction of PAs with CH2Cl2 was 9, and the extraction should be performed with four portions of 30 mL of CH2Cl2. This procedure could be also useful for a plant sample preparation for GC and LC analyses of PAs.
Asunto(s)
Boraginaceae/química , Fraccionamiento Químico/métodos , Alcaloides de Pirrolicidina/aislamiento & purificación , SolventesRESUMEN
The examination of the aerial parts, roots, and seeds of the endemic plant Rindera umbellata is reported in this paper for the first time. Phytochemical investigation of R. umbellata led to the isolation and characterization of ten pyrrolizidine alkaloids and eleven fatty acids in the form of triglycerides. Pyrrolizidine alkaloids 1-9 were found in the aerial parts, 7 and 8 in the roots, and 6-10, together with eleven fatty acids, in the seeds of this plant species. The structures of compounds 1-10 were established based on spectroscopic studies (¹H- and ¹³C-NMR, 2D NMR, IR and CI-MS). After trans-esterification, methyl esters of the fatty acids were analyzed using GC-MS. The effect of lindelofine-N-oxide (7) on tubulin polymerization was determined.
Asunto(s)
Boraginaceae/química , Ácidos Grasos/química , Extractos Vegetales/química , Alcaloides de Pirrolicidina/química , Semillas/química , Moduladores de Tubulina/química , Tubulina (Proteína)/química , Animales , Antineoplásicos/química , Bovinos , Ácidos Grasos/aislamiento & purificación , Componentes Aéreos de las Plantas/química , Raíces de Plantas/química , Polimerizacion , Multimerización de Proteína/efectos de los fármacos , Alcaloides de Pirrolicidina/aislamiento & purificaciónRESUMEN
Mass spectrometry has been applied in order to study the main fragmentation routes of some 4-pyrimidene carboxylic acids. Differences in fragmentation were caused by the nature of the substituent in position 2 of the pyrimidine ring, while the methyl group in position 1, 3 or 6 did not influence the fragmentation route.
