RISTOMYCIN A AGLYCONE, 41-[[[(4-BUTYLPHENYL)METHYL]AMINO]METHYL]-22, 31-DICHLORO-38-DE(METHOXYCARBONYL)-7-DEMETHYL-19-DEOXY-N15-[(1,1-DIMETHYLETHOXY)CARBONYL]-38-[[(METHYLAMINO)CARBONYL]-