Optimization of arabinogalactan and taxifolin extraction process from Dahurian larch (Larix gmelinii ) and evaluation of the effects on activities of α-amylase, α-glycosidase, and pancreatic lipase in vitro

Abstract

Double experimental designs, Plackett–Burman design coupled with Box–Behnken design, were used to optimize the simultaneous extraction process of arabinogalactan and taxifolin from Larix gmelinii by ultrasonic microwave synergistic extraction (UMSE) method. The optimal extraction conditions were determined with the extraction yields of 223.40 ± 7.82 mg/g for larch arabinogalactan and 125.02 ± 5.30 mg/g for taxifolin. Compared to conventional methods, UMSE method showed the merits of higher extraction efficiency, saving time, and energy. The molar ratio of galactose to arabinose is found to be 6:1 through the monosaccharide composition analysis of larch arabinogalactan. The obtained taxifolin structure was identified by mass spectrometry, Fourier transform infrared spectroscopy, and nuclear magnetic resonance. Interestingly, larch arabinogalactan and taxifolin showed completely opposite influences on α‐amylase, α‐glycosidase, and pancreatic lipase; it was inferred that larch arabinogalactan could act as an inhibitor while taxifolin as an accelerator. Practical applications In this study, response surface methodology of Plackett–Burman design and Box–Behnken design performed well to obtain the optimal conditions and satisfactory extraction yields for the extraction of arabinogalactan and taxifolin from Larix gmelinii by ultrasonic microwave synergistic extraction method, which could be a good paradigm for the efficient isolation of bioactive substances from plant matrix in the field of separation science. Meanwhile, the results from the evaluation of the effects of two target compounds on activities of α‐amylase, α‐glycosidase, and pancreatic lipase in vitro revealed that larch arabinogalactan and taxifolin enjoyed the completely opposite influences on the three digestive enzymes, namely larch arabinogalactan could act as an inhibitor while taxifolin an accelerator. These results will facilitate the application of larch arabinogalactan and taxifolin in the food and pharmaceutical industries.

Understanding the Formation of Heartwood in Larch Using Synchrotron Infrared Imaging Combined With Multivariate Analysis and Atomic Force Microscope Infrared Spectroscopy

“…Component III shows prominent IR bands at 1637, 1658, and 1728 cm -1 in the ray, tracheid lumen, and S3 layer. The band around 1637 cm -1 was assigned to the ketone bond in taxifolin (Ruddick and Xie, 1994;Miklečić et al, 2012;Kocábová et al, 2016;Liu et al, 2018), one of the most abundant phenolic compounds in larch wood (Giwa and Swan, 1975;Babkin et al, 2001;Ivanova et al, 2012;Zule et al, 2017) (see reference spectrum of taxifolin in Figure S4 for comparison). The other peaks seen in the taxifolin spectrum are not seen due to overlap with the spectra of the structural wood cell wall biopolymers.…”

“…(B) Related pure spectra. FIGURE S4 | FTIR spectrum of taxifolin crystal according to (Liu et al, 2018).…”

Optimization of the polysaccharide extraction process from natural raw materials

“…Богино долгион ашиглах үед уусмалын температур огцом өсдөг тул дулаанд тэсвэргүй полисахаридуудын молекул массын тархалт болон бүтцийг өөрчлөх магадлалтай [6]. [10]. Арабиногалактаныг ихэвчлэн халуун усаар хандалж этилийн спиртээр тунадасжуулах аргаар гарган авдаг [11].…”