The chemistry of peptides related to metabolites of Trichoderma spp. 2. An improved method of characterization of peptides of 2-methylalanine

Abstract

I. M. SHAW and A. TAYLOR. Can. J. Chem. 64, 164 (1986).4-Chlorobenzoylazide reacts with amino acid and peptide esters to give the 4-chlorobenzoyl derivatives in 60-90% yield, at room temperature, without measurable racemization. The reaction also proceeds smoothly with hindered amines such as methyl 2-methylalaninate and with secondary amines, e.g. methyl L-prolyl-L-valinate. Ten examples of the reaction are reported with peptides, synthesized for the purpose, that might be accessible from hydrolysates of the numerous fungal metabolites now known, which contain a high proportion of 2-methylalanine. The derivatives of di-, tri-, tetra-, and pentapeptides were highly crystalline, with sharp melting points, and could be detected and integrated in the effluent from chromatography columns at about the 10-ng level. This simple method of derivatization might be usefully applied to the resolution of discrepancies in the physical properties of ostensibly the same 2-methylalanyl peptide prepared in different laboratories.I. M. SHAW et A. TAYLOR. Can. J. Chem. 64, 164 (1986). L'azoture du chloro-4 benzoyle rkagit avec les esters d'acides aminks et de peptides, B la tempCrature ambiante, pour conduire aux dCrivks chloro-4 benzoylks avec des rendements de 60 i i 90% et sans rackmisation mesurable. La rkaction se produit aussi facilement avec des amines encombrkes, comme le mCthyl-2 alaninate de mkthyle, et avec des amines secondaires, comme le L-prolyl-L-valinate de mkthyle. On rapporte dix exemples de la reaction avec des peptides, synthCtisCs B cette fin, qui peuvent se retrouver dans les hydrolysats de plusieurs mktabolites de champignons qui sont maintenant connus pour contenir une grande proportion de mkthyl-2 alanine. Les dkrivCs des di-, tri-, tetra-et pentapeptides sont trks cristallins, ils ont des points de fusion bien dkfinis et ils peuvent itre dCtectks et intCgrCs en chromatographie a des niveaux de 10 ng. Cette simple mCthode de prkparer un dkrivC peut itre appliquke utilement B la rksolution des diffkrences dans les propriktks physiques de peptides de la methyl-2 alanine qui semblent les mimes, mais qui ont Ctk prCparCs dans des laboratoires diffkrents.

In vitro and in vivo antitrypanosomal activities of three peptide antibiotics: leucinostatin A and B, alamethicin I and tsushimycin

“…8 The present observations are the first reports of in vitro and in vivo antitrypanosomal activities of leucinostatin A and B, alamethicin I and tsushimycin. …”

Peptaibol metabolites of Tolypocladium geodes

“…Linear peptides containing a C-terminal amino alcohol, Lo1 (1 l), Phol (phenylalaninol) (12), or Trpol (tryptophanol) (13), and a high proportion of the unusual amino acid Aib (14) belong to the class of natural products known as peptaibols. The Trichodei-ma metabolites trichorzianine A (13), trichosporin B (12b,c,d), tricholongin BI and BII (1 la), trichogin A IV (1 lb), trichodecenins-I and -11 (1 1 4 , and the alamethicins (128 are among the best known peptaibols.…”

The antibacterial activity of alamethicins and zervamicins

“…There is considerable evidence (Shaw & Taylor 1986) that many genera of fungi produce peptides of molecular weight about 2000. In some cases the physiological function of these metabolites is known (Sakamoto et al 1986) but such information is, in general, uncommon.…”