Guaiacum officinale L. - Zygophyllaceae - guaiacum, lignum vitae, Guajak-Baum, Franzosenholz, Pockholz
Evergreen tree, up to 13m high, native to West Indies, Colombia, Venezuela; leaves opposite, short petioled, leathery, two- or tripinnate, leaflets obovate, obtuse; flowers showy, blueish purple to pale blue; fruit a compressed capsule heart-shaped, orange-yellow; seed perisperm red, testa black.
„The greenish brown resin yields a drug known as ‘Guaicum’. The hardest and heaviest of woods called “lignum vitae” is a remedy against morbus gallicus. The wood is extensively used for making blocks and pulleys, rulers and many other similar articles.“
http://www.efloras.org/florataxon.aspx?flora_id=5&taxon_id=250064408
„Guaiacum has a local stimulant action which is sometimes useful in sore throat. The resin is used in chronic gout and rheumatism, whilst the wood is an ingredient in the compound concentrated solution of sarsaparilla, which was formerly much used as an alternative in syphilis.“
[Wallis, Thomas E. (1955). Textbook of Pharmacognosy]
Used in folk medicine of the Caribbean to treat syphilis, skin diseases and rheumatism.
[Botanical remedies of South and Central America, and the Caribbean: an archival analysis. Part I., Hirschhorn, H.H., Journal of Ethnopharmacology, Vol.4(2), 1981, 129-158]
Guaiac refers to the resin of G.officinale and G.sanctum, constituting 18-25% of the wood of these trees. The alcoholic extract of the resin gives a royal blue color in air and may be used as sensitive test for oxidising agents like peroxidases.
[761. The chemistry of extractives from hardwoods. Part XXXVI. The lignans of Guastiacum officinale L., King, F.E., Wilson, J.G., J. Chem. Soc., 1964, 4011-4024]
„The term guaiac denotes the name of the paper surface used in the test which has a phenolic compound, alpha-guaiaconic acid, that is extracted from the wood resin of Guaiacum trees.“
https://en.wikipedia.org/wiki/Stool_guaiac_test
„α-Guaiaconic acid, the constituent of gum guaiac resin that turns blue upon oxidation, was purified by elution from a polyamide column with aqueous formic acid and shown to be 2,5-di-(4-hydroxy-3-methoxyphenyl)-3,4-dimethylfuran. The blue product, guaiacum blue, is the bis-methylenequinone obtained by twofold one-electron oxidation of α-guaiaconic acid.“
[Isolation and characterization of α-guaiaconic acid and the nature of guaiacum blue., Kratochvil, J.F., Burris, R.H., Seikel, M.K., Harkin, J.M., Phytochemistry, Vol.10(10), 1971, 2529-2531]
Woodville, W., Hooker, W.J., Spratt, G., Medical Botany, 3th edition, vol.4, t.200 (1832)
http://plantgenera.org/species.php?id_species=482112