[Hydroxycinnamic acid esters in brassicaceous vegetables and garden cress]

Area of Science:

• Phytochemistry
• Analytical Chemistry
• Food Science

Context:

• Hydroxycinnamic acid esters are significant secondary metabolites in Brassicaceae vegetables.
• Understanding the distribution of these compounds is crucial for nutritional and quality assessments.
• Previous studies have not comprehensively detailed the ester profiles across a wide range of Brassica species.

Purpose:

• To quantify and compare the profiles of caffeic, p-coumaric, and ferulic acid esters with glucose or quinic acid in several Brassica vegetables and garden cress.
• To investigate the presence of sinapoylglucose and sinapin (sinapoylcholine).
• To differentiate the ester patterns among various Brassica species using High-Performance Liquid Chromatography (HPLC).

Summary:

• Two distinct HPLC methods with gradient elution were employed to analyze hydroxycinnamic acid esters in cauliflower, kale, Brussel sprouts, red cabbage, white cabbage, Savoy cabbage, Chinese cabbage, and garden cress.
• Sinapoylglucose was the dominant glucose ester in garden cress and other Brassica species, with minor feruloylglucose detected.
• Neochlorogenic acid (5-caffeoylquinic acid) was the main quinic acid ester, while sinapoylquinic acid was not detected. Sinapin was found only in trace amounts in some Brassica species.

Impact:

• Provides a detailed phytochemical profile of key Brassica vegetables, aiding in cultivar selection and breeding programs.
• Establishes a baseline for comparing hydroxycinnamic acid ester content, potentially influencing dietary recommendations and health benefits research.
• Highlights the variability in ester patterns, suggesting species-specific metabolic pathways and potential for targeted crop improvement.