123951-82-6 AIDS-000526 AIDS000526 H-.alpha.-Aminobutyric acid-Thr-Asn-Tyr-Thr-OCH3 H-Abu-Thr-Asn-Tyr-Thr-OCH3 L-Threonine, L-2-aminobutanoyl-L-threonyl-L-asparaginyl-L-tyrosyl-, methyl ester