Synthesis of small combinatorial libraries of natural products: identification and quantification of new long-chain 3-methyl-2-alkanones from the root essential oil of Inula helenium L. (Asteraceae).
Phytochem Anal
; 25(1): 75-80, 2014.
Article
en En
| MEDLINE
| ID: mdl-23922264
ABSTRACT
INTRODUCTION:
Recently, a potent anti-staphylococcal activity of Inula helenium L. (Asteraceae) root essential oil was reported. Also, bioassay guided fractionation of the oil pointed to eudesmane sesquiterpene lactones and a series of unidentified constituents as the main carriers of the observed activity.OBJECTIVE:
To identify nine new constituents (long-chain 3-methyl-2-alkanones) from a fraction of this root essential oil with a low minimum inhibitory concentration value (0.8 µg/mL) by employing a synthetic methodology that leads to the formation of a small combinatorial library of these compounds.METHODS:
The identity of these constituents was inferred from mass spectral fragmentation patterns and GC retention data. A library of 3-methyl-2-alkanones (C11 -C19 homologous series) was synthesised in three steps starting from methyl acetoacetate and the corresponding alkyl halides. The synthetic library was also screened for in vitro anti-microbial activity.RESULTS:
Gas chromatographic analyses of I. helenium essential oil samples with spiked compounds from the synthesised library corroborated the tentative identifications of the long-chain 3-methyl-2-alkanones. The availability of these anti-microbial compounds from this library made it possible to construct GC/FID calibration curves and determine their content in the plantmaterial:
0.08 - 24.2 mg/100 g of dry roots.CONCLUSION:
The small combinatorial library approach enabled the first unequivocal identification of long-chain 3-methyl-2-alkanones as plant secondary metabolites, and, also, allowed determination of not only a single compound and biological properties, but those of a group of structurally related compounds.Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Aceites Volátiles
/
Raíces de Plantas
/
Inula
/
Bibliotecas de Moléculas Pequeñas
/
Antiinfecciosos
Tipo de estudio:
Diagnostic_studies
Idioma:
En
Revista:
Phytochem Anal
Asunto de la revista:
BOTANICA
/
QUIMICA
Año:
2014
Tipo del documento:
Article