Effects of different pretreatments on flavonoids and antioxidant activity of Dryopteris erythrosora leave

Abstract

18Flavonoids with wide bioactivity for medcine are vital secondary metabolite of plant. The factors 19 influenced on flavonoids had been reported. However, as the key processes lead to metabolite 20 alterations, the influences of the different pretreatments of samples on flavonoids and antioxidant 21 activity of ferns were with little information. Therefore, Dryopteris erythrosora leaves were chosen 22 as the materials for analyzing flavonoids alterations, which would not only provide the significant 23 basic data for flavonoid metabolism of fern, but also for further developing fern resources. The 2 24 results showed that a) The total flavonoids contents of D. erythrosora leaves with different 25 pretreatments were obviously different. The total flavonoid contents of samples, which was dried in 26 shade firstly and then dried at 75 °C in oven, finally smashed, was the highest (7.6%), but that of 27 samples, which was quickly dried at 75 °C in oven directly after cleaning and then smashed, was the 28 lowest (2.17%); b) Antioxidant activities of D. erythrosora leaves with different pretreatments were 29 variant. Samples, which were dried in shade firstly and then dried at 75 °C in oven, finally smashed 30 and samples which were firstly dried in the sun and then dried at 75 °C in oven, ultimately smashed, 31 both showed stronger antioxidant activity; c) Total twenty-three flavonoids with four different 32 pretreatments were tentatively identified by HPLC-ESI-TOF-MS. In conlusion, a) The influences of 33 different pretreatments on flavonoids and antioxidant activity of D. erythrosora Leaves were 34 obvious. b) The best pretreatment in respect to conserving fern medical application was drying in 35 shade firstly and then drying at 75 °C in oven, finally smashed. 36

In vivo antiplasmodial and toxicological studies of Dialium angolense Welw. Ex Oliv. (Fabaceae) leaves extracts, a medicinal plant from Eastern Congo

“…Indeed, the antioxidant activity on DPPH, expressed as IC50 in μg / mL, of several species of the genus Dialium is reported in the literature, D. indum, 181.6 ± 0.4 [33,34], D. guineense, 50.23 ± 0.15 [35], D. corbisieri, 14.44 ± 0.12 and D. gossweileri, > 500 [36], D. cochinchinensis, 65.01 ± 0.12 [37]. This interesting antioxidant activity observed in D. angolense would be linked to the presence of phenolic compounds mainly flavonoids, identified and quantified within the plant during this study (table 2), as well as several previous studies which testify to the antioxidant activity of flavonoids [38][39][40][41][42]. Besides flavonoids, other antimalarial [43,44] and antioxidant [45][46][47] compounds belonging from other phytochemical groups identified in the leaves of D. angolense during this study has been isolate.…”

Effect of dehydration on phenolic compounds and antioxidant activity of blackcurrant (Ribes nigrum L.) pomace

“…Zhang et al . (2019) reported that MY3G increased and QU3R decreased during drying pre‐treatment at 75℃ in Dryopteris erythrosora leaves, whereas QU3R has better heat stability than QU3G (Rohn et al ., 2007).…”