| abstract |
ABSTRACT Compounds of the formula in which X is hydrogen or the radical -CH2OR5, three of R2, R3, R4 and R5 each independently is hydrogen or and the fourth is Z each independently is oxygen, sulfur, NH or CH2, and R1, R6 and R7 each independently is an optionally substituted hydrocarbon radical having up to 50 C atoms, stimulate the immune system's response and antibody production. |