@article {2183,
	title = {Intraannular Savige-Fontana reaction: One-step conversion of one class of monocyclic peptides into another class of bicyclic peptides},
	journal = {Chemistry-a European Journal},
	volume = {14},
	number = {11},
	year = {2008},
	note = {ISI Document Delivery No.: 291XITimes Cited: 1Cited Reference Count: 34May, Jonathan P. Perrin, David M.},
	pages = {3404-3409},
	type = {Article},
	abstract = {Cyclisation and cross-linking strategies are important for the synthesis of cyclic and bicyclic peptides. These macrolactams are of great interest due to their increased biological activity compared to linear analogues. Herein, we describe the synthesis of a cyclic peptide containing an Hpi toxicophore, reminiscent of phakellistatins and omphalotins. The first intraannular cross-linking of such a peptide is then presented: using neat TFA to catalyse a Savige-Fontana tryptathionylation, the Hpi-containing peptide is converted to a bicyclic amatoxin analogue. As such, this methodology represents an efficient cyclisation method for cross-linking peptides and exposes a heretofore unrealised relationship between two different classes of peptide natural products. This finding increases the degree of potential chemical space for library generation.},
	keywords = {2-CHLOROTRITYL CHLORIDE, 2-THIOETHER DERIVATIVES, amatoxin, ANALOGS, CROSS-LINKING, CYSTEINE SULFHYDRYL-GROUPS, ILE3-AMANINAMIDE, indole, ISOPHAKELLISTATIN-3, natural products, OXIDATION, PEPTIDES, PHALLOTOXINS, RNA POLYMERASE-II, TRYPTOPHAN},
	isbn = {0947-6539},
	url = {<Go to ISI>://000255230200019},
	author = {May, J. P. and Perrin,David M.}
}
@article {2182,
	title = {Synthesis, characterisation, and in vitro evaluation of Pro(2)-Ile(3)-S-deoxo-amaninamide and Pro(2)-D-allo-Ile(3)-S-deoxo-amaninamide: Implications for structure-activity relationships in amanitin conformation and toxicity},
	journal = {Chemistry-a European Journal},
	volume = {14},
	number = {11},
	year = {2008},
	note = {ISI Document Delivery No.: 291XITimes Cited: 0Cited Reference Count: 39May, Jonathan P. Fournier, Pierre Patrick, Brian O. Perrin, David M.},
	pages = {3410-3417},
	type = {Article},
	abstract = {The amatoxins are a family of toxic bicyclic peptides that inhibit RNA polymerase II. Herein we discuss an improved synthesis of these compounds from easily obtainable amino acids by means of a solid-phase methodology. Interestingly, we obtained two products of the same mass following our final macrocyclisation, relating to a similar distribution of products described in some previous reports. One of these products was the desired amatoxin; Pro(2)-Ile(3)-S-deoxo-amaninamide 1b. The other compound, after thorough investigation, was confirmed to be the epimer Pro(2)-D-allo-Ile(3)-S-deoxo-amaninamide la, not an atropisomer structure as previously suggested in syntheses of related amanitin analogues. Crystallographic data of la confirms the presence of a beta II-turn, rather than a PI-turn common to the natural toxin and 1b. This difference explains the large variation in CD spectra, although it seems to have relatively little effect on the bioactivity in vitro. These data provide new insights into the bicyclic amatoxin structure.},
	keywords = {ALPHA-AMANITIN, amatoxin, atropisomerism, circular dichroism, CRYSTALLINE STATE, CYCLIZATION, CYSTEINE SULFHYDRYL-GROUPS, EPIMERIZATION, MOLECULAR-STRUCTURE, PEPTIDES, RESOLUTION, RNA-POLYMERASE-II, SERIES, TOXIN BETA-AMANITIN, transcription},
	isbn = {0947-6539},
	url = {<Go to ISI>://000255230200020},
	author = {May, J. P. and Fournier, P. and Patrick, B. O. and Perrin,David M.}
}
