Abstract: The invention relates to a method for separating proteins from liquid media, comprising providing a liquid medium containing proteins, providing a clay material which has: a specific surface greater than 150 m2/g, a pore volume greater than 0.35 ml/g, an ion exchange capacity greater than 40 meq/100 g, and a sediment volume in water of less than 15 ml/2 g, equilibrating said clay material to a pH of from 3.5 to 9.0, treating said liquid medium with the equilibrated clay material, and separating the purified, protein-depleted liquid medium from the clay material.

Abstract: The invention relates to ratjadone derivatives which can stop the cell cycle of tumour cells in the G1 phase and/or exhibit a reduced cytotoxicity as ratjadone. According to the invention, the ratjadone derivatives correspond to formula (II) wherein R1, R2 and R3 are selected independently from each other from the group which is made of H, CH3 and C2H5, R4 is CH3 or C2H5, R5 is H or OH and R6 and R7 are selected independently from each other from the group which is made of H, CH3, C2H5, n-C3H7, and iso C3H7, and wherein C10 is R-configured and C17 is R-configured if (a) C16 is R-configured and simultaneously (b) neither R5, nor R6, nor R7 are H. The invention also relates to a method for synthesizing ratjadone derivatives.