β-Phenylselenoalanine as a dehydroalanine precursor–efficient synthesis of alternariolide (AM-toxin I)
摘要:
Alternariolide (AM-toxin) is synthesized in 44% overall yield from L-2-amino-5-(4-methoxyphenyl)pentanoic acid; D-beta-phenylselenoalanine is used as the dehydroalanine precursor.
Condensation of amide with α-ketoacid to yield a α-hydroxyalanine (α-Hyala) or dehydroalanine residue was applied to syntheses of analogs of AM-toxins, cyclotetradepsipeptides. Cyclo(-α-Hyala-L-Ala-L-Val-L-Phe-), cyclo(-α-Hyala-L-Ala-L-Hmb-L-Phe-) and cyclo(-α-Hyala-L-Ala-L-Hmb-L-Tyr-) (Hmb, 2-hydroxy-3-methylbutanoic acid) were obtained from the corresponding pyruvyl-tripeptide amides in good yields by the
A photoaffinity-labelinganalog of alternariolide (AM-toxin I) which contains L-2-amino-5-[4-(1-azi-2,2,2-trifluoro)ethylphenyl]pentanoic acid (10) was synthesized.
A new fluorescent amino acid, L-2-amino-5-(10-methoxy-9-anthryl)pentanoic acid (L-Amap, 3) was synthesized and incorporated into alternariolide instead of L-Amp (L-2-amino-5-(4-methoxyphenyl)-pentanoic acid.
An AM-toxin II analog, cyclo(–L-Ala1–L-Hmb2–L-App3–Hyala4–), with an α-hydroxyalanine (Hyala) residue in place of dehydroalanine in position 4 was synthesized from pyruvoyl–L-Ala–L-Hmb–L-App–amide (Hmb, 2-hydroxy-3-methylbutanoic acid; App, 2-amino-5-phenylpentanoic acid) by intramolecular condensation between the pyruvoyl and carbamoyl groups. The synthetic peptide did not show the toxic activity
AM-毒素 II 类似物,环(–L-Ala1–L-Hmb2–L-App3–Hyala4–),用 α-羟基丙氨酸(Hyala)残基代替第 4 位的脱氢丙氨酸是从丙酮酰-L-Ala –L-Hmb–L-App–酰胺(Hmb,2-羟基-3-甲基丁酸;App,2-氨基-5-苯基戊酸)通过丙酮酰基和氨基甲酰基之间的分子内缩合。合成肽没有表现出 AM-毒素 II 的毒性活性。
Synthesis of Alternariolide Analogs for Photoaffinity-Labeling