Crataegusins A and B, New Flavanocoumarins from the Dried Fruits of Crataegus pinnatifida var. major (Rosaceae)

Abstract

Crataegusins A (1) and B (2), new flavanocoumarins, were isolated from the crude drug Crataegus Fructus, i.e., the dried fruits of Crataegus pinnatifida var. major. Their structures were determined by spectroscopic methods. They were unique in terms of carrying a 3-(or 4-)substituted coumarin substructure while a flavanocoumarin generally does not carry any substituents in the 2-pyron ring. They showed a significant DPPH reducing activity compared with epicatechin. Their production would be biosynthetically regulated considering the results of an LC-MS analysis of the dried and fresh fruits, fruit skin, hypanthia, and leaves. Their structures led the authors to consider a hypothetical general biosynthetic pathway of the flavanocoumarins, to which a flavan-3-ol is converted through a Michael addition and successive oxidative decarboxylation or dehydration pathway.

Phytochemical composition and bioactivities of hawthorn ( Crataegus spp.): review of recent research advances

“…Epicatechin, aglycons and glycosides of B-type oligomeric procyanidins and flavonols, phenolic acids and C-glycosyl flavones as he major groups of phenolics; in vitro and animal studies showing cardioprotective, hypolipidaemic, hypotensive, antioxidant, radical-scavenging and anti-inflammatory potentials Yang and Liu, 2012 Phytochemical composition and bioactivities of hawthorn (Crataegus spp.) Venskutonis a significant DPPH • reducing activity compared with epicatechin (Kazuma et al, 2016). Most of the compounds isolated from the 70% ethanolic extract of C. pinnatifida seeds showed moderate DPPH • scavenging activity and significant activities in the FRAP and ABTS assays.…”

“…Phytochemical studies of the most widely used C. pinnatifida (Table 2) resulted in separation and purification of 4 new monoterpene glycosides and a new phenolic glycoside in addition to the 10 previously known ones . Furthermore, 15 triterpenoids, including 4 novel acids, in hawthorn berries (Qiao et al, 2015); 2 norditerpenoids with unique carbon skeletons, 4 sesquiterpenoids and 9 nor-sesquiterpenoids from the ethanolic extract of plant leaves (Gao et al, 2017); 8 new phenylpropanoids (crataegusoids A-F) from the fruits (Guo et al, 2018); 8 new lignans (hawthornnins A-H) and 7 known analogues (Huang et al, 2015a); 2 new 8-O-4′-neolignans, huangnin A and B and four known analogs (Huang et al, 2015b); 7 new lignans (crataegusnins A-G) and 5 known compounds from the seeds (Peng et al, 2016) and from crude Crataegus Fructus drug (Kazuma et al, 2016), while 7 known main constituents were separated from the flavonoid fraction of leaves using a combination of high-speed counter-current chromatography (HSCCC) coupled with pre-HPLC (Wen et al, 2017). Crataegusins A and B, new flavanocoumarins, also showed…”