Obtaining, producing and using metabolites having anti-botrytis cinerea properties from a natural extract of a native Chilean plant. An in vitro cultivated quillay extract (Quillaza saponaria Mol.), which allows improving the antifungal activity as the result of the enrichment of some secondary metabolites not found in the in vivo plants. Also provided are an in vivo cultivation method, an extraction method, a biocide formulation, and their applications and uses.