In prenylation methods

Two major synthetic strategies have been applied for the synthesis of S-prenylated peptides as shown in Scheme 1. In the first approach (method A), S-alkylation is performed on the final peptide in a protected or unprotected form.13641 In method B, which has produced better results in terms of overall yield, thiol alkylation is carried out on the cysteine residue or on a small peptide fragment and then the S-prenylated synthons are coupled to the remaining peptide fragment to produce the final products.[45 501 Most of the procedures reported for the synthesis of farnesylated peptide derivatives, can also be applied to the synthesis of geranylgeranylated peptides. 

Recent developments in delayed extraction TOF allow higher resolving power and mass accuracy, and this method in the reflector mode has been used for accurate measurement of the mass of several compounds including two prenylated flavonoids. However, the performance of the MALDI-TOF instrument was not better than those of the FAB and FT-ICR MS instruments, and insufficient to give acceptable accuracy for literature reporting. 

We have demonstrated that this insect cell-free protein synthesis system is one of the most effective protein synthesis systems among those based on animal extracts (2). Furthermore, it has the potential to perform eukaryote-specific protein modifications such as protein W-myristoylation and prenylation (3, 4). Thus, we expect that the insect cell-free protein synthesis system will be a useful method for target protein production in the reverse chemical genetics era, as well as for postgenomic studies. In this chapter, we describe standard protocols to synthesize proteins of interest using the insect cell-free protein synthesis system. 

Hydroxy-l-methyl-3-prenyl-2-quinolones, cf. (22), are key intermediates in the synthesis of quinoline alkaloids, and usually are prepared in one stage from an N-methyl-aniline and diethyl prenylmalonate. Interesting new methods beginning with N-methylisatoic anhydrides, cf. (20), have been explored and briefly repor-... 

The trans allylic alcohol needed to make this compound was made using one of the methods we introduced in Chapter 3i reduction of an alkynyl alcohol with LiAlEL]. Here is the full synthesis alkylation of an ester enolate with prenyl bromide gives a new ester, which itself is turned into an alkylating agent by reduction and tosylation. The alkyne is introduced as its lithium derivative with the alcohol protected as a THP acetal. Hydrolysis of the acetal with aqueous acid gives the hydroxy-alkyne needed for reduction to the E double bond, which is then epoxidized. 

Hrycyna, C.A., Wait, S.J., Backlund, P.S., Jr., and Michaelis, S. (1995). Yeast STE14 methyltransferase, expressed as TrpE-STE14 fusion protein in Escherichia coli, for in vitro carboxylmethylation of prenylated polypeptides. Methods Enzymol 250 251-266. 

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