Phytochemical Characterization of Extracts From Aesculus hippocastanum L. Seeds and Quantification of Saponins Using HPLC-DAD and a Novel Tensiometric Approach.

Aesculus hippocastanum L. is a well-established medicinal plant used for the treatment of venous disorders and inflammation. Despite its wide therapeutic application, systematic comparisons of the phytochemical profile of horse chestnut seed extracts prepared according to pharmacopeial extraction protocols remain scarce. Consequently, this study aimed to characterize and compare the metabolite profiles of hydroalcoholic and aqueous fermented seed extracts prepared according to official pharmacopeial procedures. Extracts were analyzed using high-performance liquid chromatography coupled to diode array and electrospray ion-trap mass spectrometric detection (HPLC-DAD-ESI-MSn) and gas chromatography-mass spectrometry (GC-MS). Additionally, a novel approach was developed for the semi-quantification of saponins by tensiometry, which was compared with the quantification of UV-active aescin derivatives by RP-HPLC-DAD. The HPLC-DAD-MSn analyses revealed different phytochemical compositions that include triterpene saponins, flavonoid glycosides, and indoleacetic acid-N-glycosides. GC-MS analyses mainly revealed the presence of fatty acids, monosaccharides, and lactic acid. The hydroalcoholic extract showed higher aescin contents by RP-HPLC-DAD compared to the aqueous fermented extract, indicating better recovery rates with this extraction procedure. These findings underline the importance of process parameters in pharmaceutical manufacturing and support the use of complementary analytical approaches for comprehensive quality evaluation of complex herbal extracts.