Synthesis and bioactivity evaluation of lignin related high-added-value 1,4-dihydropyridines and polyhydroacridines

A series of 4-aryl-1,4-dihydroquinolines and 9-aryl-3,4,6,7,9,10-hexahydroacridine-1,8(2H,5H)-diones were prepared by Hantzsch reaction using aromatic aldehydes obtained from lignin. Their antioxidant properties were evaluated by scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and 2,2′-azino-bis (3-ethylenzothiazoline-sulphonic acid) diammonium salt (ABTS+) radical. Antihypertensive activities were also determined in spontaneously hypertensive rats (SHRs) during different time. The results show that the compounds containing syringyl moiety exhibit better antioxidant and antihypertensive activities than those containing guaiacyl and p-hydroxyphenyl moieties.

► 1,4-Dihydroquinolines and polyhydroacridines were obtained from lignin.
► 4a, 4d and 6a exhibited very potent antioxidant activity.
► 4a and 6a also showed good antihypertensive activity.
► It provided an effective approach for value-added application of lignin.