Hostaflavanol A, a new anti-inflammatory and antioxidant activities flavanol from the flowers of Hosta plantaginea

Abstract

A new flavan-3-ol glycoside, hostaflavanol A (1) along with two related known ones, including dihydrokaempferol (2) and naringnin (3) were isolated from the 80% ethanol extract of Hosta plantaginea flowers. Their structures were elucidated on the basis of chemical and spectral evidence, as well as by comparison with literature data. To the best our knowledge, compounds 2 and 3 were characterized for the first time from the Liliaceae family and genus Hosta, respectively. The anti-inflammatory activity against cyclooxygenases (COX-1 and COX-2) in vitro results revealed that compounds 1‒3 exhibited significant or moderate COX-1 and moderate COX-2 inhibitory effects with IC50 values of 23.7 ± 1.8, 31.6 ± 1.6, and 61.3 ± 3.1 μM for COX-1, as well as 46.7 ± 3.1, 71.2 ± 3.5, and 115.7 ± 6.5 μM for COX-2, respectively. Furthermore, the antioxidant activity of compounds 1‒3 was also measured by the DPPH method, 1‒3 exhibited significant or moderate antioxidant activities with IC50 values of 112.7 ± 3.8, 46.6 ± 1.3, and 82.4 ± 2.4 μM, respectively.