Abstract: Compounds termed "vitaletheine modulators" which include beta-alanyl-taurine and carbobenzoxy beta-alanyl-taurine are synthesized and added to culture media for in vitro culture of cells such as mammalian or plant cells. The compounds support cell vitality, and provide increased cellular life span, increased cellular bioproductivity, improved cellular function, and adaption of resistant cells to culturing. Carbobenzoxy beta-alanyl-taurine is produced by coupling .beta.-alanine, which has it's terminal amine protected with a carbobenzoxy (CBZ) group, to N-hydroxysuccinimide to produce an active ester of .beta.-alanine, coupling two of the active esters to cystamine to produce a CBZ-protected .beta.-alethine having an internal disulfide bond, isolating and purifying the CBZ-protected .beta.-alethine, and reacting the CBZ-protected .beta.-alethine with iodine to oxidize the disulfide bond to obtain carbobenzoxy beta-alanyl-taurine.