Patent ID: 8496974

Claim:
A method for preparing a composition, comprising: (i) pulverizing and/or extracting wood material with an organic solvent to obtain a wood extract, the extracted wood material comprising: (a) 50-99.9 wt % of at least two different compounds selected from the group consisting of: lignans, stilbenes, juvabiones, flavonoids, betulin, betulonic acid, betulinic acid, and betuloinic acid, and ester derivatives, ether derivatives or stereoisomers thereof; and (b) 1-31 wt % of oligomers of lignans, stilbenes, juvabiones or flavonoids, wherein at least one compound of said two different compounds is selected from the group consisting of: 7-hydroxymatairesinol, conidendrin, conidendric acid, alpha-conidendrin, alpha-conidendric acid, isohydroxymatairesinol, cyclolariciresinol, secoisolariciresinol, anhydrosecoisolariciresinol and stilbenes, and ester derivatives, ether derivatives or stereoisomers thereof; (ii) measuring cytotoxicity of said wood extract, the cytotoxicity being measured with a HaCat cell culture after a 24 hour incubation period; (iii) selecting a wood extract having a cytotoxicity at 0.1-5 wt % in ethanol that is lower than the cytotoxicity of 0.02-0.1 wt % butylated hydroxytoluene (BHT) in ethanol; and (iv) mixing said selected wood extract with a carrier agent.