400 containing 10 ethanol held at 37 u00b0 c the structure has no readily reactive groups which might otherwise confer instability being a diterpene ester ebi 46 is highly soluble in organic solvents including biocompatible solvents such as acetone alcohols and peg 400 it requires a small amount of such solvents to form aqueous solutions solubility tests have demonstrated 100 solubility at all 3 concentrations tested so far 45 u03bcg ml in 90 water 50 u03bcg ml in 99 water and 5 u03bcg ml in 99 9 water higher solubilities may well be achievable note that ebi 46 is a potent drug and only small amounts are required thus for intralesional injection of ebi 46 the concentration was 400 u03bcg ml and no water was required in this case 3 bioactivity profile of ebi 46 and related compounds in vitro arrest of cell growth the ability of the eb548 crude extract table 13 and purified ebi 46 fig4 to block the growth of cultured human tumor cell lines and a normal strain human diploid fibroblasts was tested in a clonogenic type assay where many generations were allowed to elapse 5 6 days treatment before measuring cell growth sulfurhodamine protein stain changes in morphology were also.