1,2-Benzenediol, 4,4'-(2,3-dimethyl-1,4-butanediyl)bis-, (R*,S*)- 27686-84-6 (MESO) AIDS-025463 AIDS025463 CHX 100 Masoprocol meso-4,4'-(2,3-Dimethyltetramethylene)dipyrocatechol meso-NDGA meso-Nordihydroguaiaretic acid