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