.beta.-D-Xylopyranoside, (3.beta., 5 .alpha.,6 .alpha.,15.beta.)-3,6,8,15-tetraydroxyergost-24(28)-en-26-yl 2-O-(2-O-methyl-.beta.-D-xylopyranosyl)-, 3-(sodium sulfate) AIDS-168487 AIDS168487 Certonardoside C