Seasonal Changes and Effect of Harvest on Glucosinolates in Isatis leaves

Abstract

The seasonal fluctuation of glucosinolates in five defined Isatis tinctoria and one Isatis indigotica accessions (first year, rosette stage), grown on field plots under identical conditions, was investigated. Analysis of the intact glucosinolates was carried out with shock frozen, freeze dried leaf samples using a recently developed and validated PLE (pressurized liquid extraction) protocol and ion-pair HPLC coupled with ESI-MS in the negative mode. When comparing the two Isatis species, significant qualitative and quantitative differences in the glucosinolate patterns were observed. Differences among the various Isatis tinctoria accessions were much smaller. We studied the effects of repeated harvesting during the growth season on glucosinolate concentrations and found that repeated harvest did not have a major effect on glucosinolate concentrations of newly grown leaves. Glucosinolates could not be detected in woad leaves submitted to conventional drying.

Glucosinolate Pattern inIsatis tinctoriaandI. indigoticaSeeds

“…478.0716, found: 478.0713), was detected as a trace compound in both I. indigotica seed samples, but was absent from any of the I. tinctoria accessions. A recent comparison of glucosinolate patterns in leaves revealed significant qualitative and quantitative differences between the two Isatis sp., but comparativey small differences between the I. tinctoria accessions [11]. A similar observation could be made in case of the seeds.…”

“…Comparison of fragmentation conditions. In-source fragmentation gave equal or higher relative signal intensities compared to fragmentation by MS/ MS, and the absolute signal intensity was clearly higher for the sulfate fragment m/z = 97 via in-source fragmentation dominant in the leaves [11]. In summary, our findings show organ-specific differences in glucosinolates.…”

“…These two compounds have been recently identified as an unseparable epimeric mixture from I. tinctoria seeds [14]. The two compounds were not found in leaves of the two species [11] and thus can be considered as markers of seed material. Two other glucosinolates reported by Frechard et al [14], 3′-hydroxyglucoisatisin and 3′-hydroxyepiglucoisatisin, could not be detected in any of the Isatis seed samples.…”

“…In recent years, the two species were intensively investigated from a phytochemical and pharmacological viewpoint [2], [3], [4], [5], [6], [7], and in a clinical pilot study [8]. Seasonal variation of the two most abundant classes of secondary metabolites in Isatis leaves, indigo precursors and glucosinolates, and changes in metabolite profiles during post-harvest treatment have been studied [9], [10], [11]. Characteristic differences in glucosinolate pattern were observed in leaves of I. tinctoria and I. indigotica, corroborating the recent separation into two distinct species [12].…”

Effects of Methyl Jasmonate and Putrescine on Tryptanthrin and Indirubin Production in in vitro Cultures of Isatis demiriziana Mısırdalı

“…Isatis is herbaceous plants belonging to the family Brassicaceae (Cruciferea). The roots and leaves of Isatis have anti-viral, antiinflammatory and anti-tumor effects and the leaves of these plants are used as a source of indigo (blue dye) [2][3][4][5]. Recently, a number of active constitutients have been isolated from plants belonging to the Isatis genus mainly Isatis tinctoria and Isatis indigotica such as terpenoids, phenylpropanoids and alkaloids.…”