Guanosine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-6-O-[(diphenylamino)carbonyl]-N-(1-oxopropyl)-P(S)-phenyl-P-thioguanylyl-(3′→5′)-6-O-[(diphenylamino)carbonyl]-N-(1-oxopropyl)-P(S)-phenyl-P-thioguanylyl-(3′→5′)-6-O-[(diphenylamino)carbonyl]-N-(1-oxopropyl)-P(S)-phenyl-P-thioguanylyl-(3′→5′)-N-benz...