Table 2. Propertes of Different Geometric Isomers of AXT^a.

property	type of isomer	type of assay	ref
antioxidant capacity	13Z > all-E > 9Z	CAA assays (Caco2-BBe1/HT-29)	(61)
	13Z > 9Z > all-E	ORAC-L, PLC assays	(61)
	9Z > 13Z > all-E	DPPH and lipid peroxidation assay (SH-SY5Y cells)	(62)
transport efficiency	9Z > 13Z > all-E	Caco-2 cell monolayer model	(55)
bioavailability/bioaccessibility	Z-isomers> all-E	oral-dosing test (human)	(63)
	all-E > 13Z > 9Z	oral-dosing test (rainbow trout)	(64)
	13Z > 9Z, all-E	oral-dosing test (human)	(65)
	13Z > 9Z> all-E	digestion model (Caco-2 cells)	(55)
stability	all-E > 9Z > 13Z	storage tests (heating and filtration)	(66)
	all-E, 13Z > 9Z	pH test	(61)
solubility	Z-isomers > all-E	organic solvents	(53)

^aAbbreviations: ORAC-L assay, oxygen radical absorbing capacity assay for lipophilic compounds; PCL assay, photochemiluminescence assay; CAA assay, cellular antioxidant activity assay; DPPH, 2,2-diphenyl-1-picrylhydrazyl; bioaccessibility, the amount of AXT available for absorption in the gut after the digestion process; bioavailability, the amount of AXT which reaches the site of physiological activity after administration.²⁵