Marfey analysis

Supporting evidence for this proposal was obtained from amino acid analyses which demonstrated that glycine was the only typical or non N-methylated amino acid present in 4ab and Sab. Marfey analysis of the acid hydrolysates of 4ab, Sab and majusculamide C (6) confirmed that 4ab and Sab differed from majusculamide C (6) in possessing an N-methyl-L-alanine residue rather than an L-alanine residue. Moreover, 4ab and Sab contained an N-methyl-L-leucine residue rather than an N-methyl-L-isoleucine residue,... 

Miraziridine A 7 is a pentapeptide natural product isolated from the marine sponge Theonella aff. mirabilis in Japan in 2000 [3], It was also isolated 12 years later from the red sea sponge Theonella swinhoei [4], Miraziridine A inhibits cathepsin B with an IC50 value of 1.4 pg/ml. The sequencing of the amino acid residues and the absolute stereochemistry of each residue were achieved by a combination of Marfey analysis and nuclear magnetic resonance (NMR) data and resulted in the following sequence (2/ ,3J )-aziridine-2,3-dicarboxylic acid (Azd) (CO)/L-leucine (Leu) (NH), Leu (CO)/(35,45)-statine (Sta) (NH), Sta (CO)/(5)-a-aminobutyric acid... 

CE has been applied extensively for the separation of chiral compounds in chemical and pharmaceutical analysis.First chiral separations were reported by Gozel et al. who separated the enantiomers of some dansylated amino acids by using diastereomeric complex formation with Cu " -aspartame. Later, Tran et al. demonstrated that such a separation was also possible by derivatization of amino acids with L-Marfey s reagent. Nishi et al. were able to separate some chiral pharmaceutical compounds by using bile salts as chiral selectors and as micellar surfactants. However, it was not until Fanali first showed the utilization of cyclodextrins as chiral selectors that a boom in the number of applications was noted. Cyclodextrins are added to the buffer electrolyte and a chiral recognition may... 

L. patella from Fiji contained patellins 1-5 (50-54) [82] and earlier, solution- and solid-state conformational studies were carried out on patellin 2 (51), and the structure was determined by X-ray analysis [83]. A Lissoclinum sp. from the Great Barrier Reef yielded patellins 3 (52), 5 (54) and 6 (55) and the heptapeptide trunkamide A (56) [82]. Compounds 50-56 were all identified by interpretation of spectral data and through use of Marfey s method to determine the absolute stereochemistry of the constituent amino acids [82]. A total synthesis of the proposed structure of trunkamide A (56) revealed that the structure... 

A Palauan species of Dysidea contained 15-acetylthioxyfurodysinin lactone (327), that binds to human leukotriene B4 (LTB4) receptor. The structure was determined by spectral data analysis and confirmed by synthesis involving photo-oxidation of 15-acetylthioxyfurodysinin (328), which co-occurs with it in the sponge [297,298]. An Australian species of Euryspongia also contained 15-acetylthioxyfurodysin (329) and 15-acetylthioxyfurodysinin (328) [299]. A sample of D. herbacea from the Great Barrier Reef contained (-)-neodysidenin (330) and the absolute configuration was determined by capillary electrophoresis of Marfey s derivatives [300]. 

An alternative solid-phase synthesis of peptide thioamides that uses methyl dithioesters to introduce the sulfur involves addition of DMAP and cesium trifluoroacetate. 24 These additives greatly accelerate the thioamide-forming reaction and give low levels of racemi-zation according to Marfey s test analysis 25 of an Alaip[C(=S)—NH]Val product. 

Thiazole-containing linear peptides have also been isolated from tunicates. Virenamides A-E (412-416) were obtained from the didemnid tunicate Diplosoma virens, which contains symbiotic prokaryotic algae in its cloacal cavity. The structures of virenamides A-C were determined by HPLC analysis using Marfey s procedure [323] while the absolute stereochemistry of virenamide E (416) was proven by its synthesis from virenamide A (412) [324], Compounds 412-416 showed modest cytotoxicity toward a panel of cultured cells and 412 also exhibited topoisomerase II inhibitory activity. 

Rogers EW, de Oliveira MF, Berlinck RGS, Konig GM, Molinski TF (2005) Stereochemical Heterogeneity in Verongid Sponge Metabolites. Absolute Stereochemistry of (+)-Fistularin-3 and (+)-ll-ep(-Fistularin-3 by Microscale LCMS-Marfey s Analysis. J Nat Prod 68 891... 

The urine (20 ml) of anadromous, ovulated females was collected by catheterization. Repeated fractionation, guided by male behavioral response, over complementary chromatographic supports led to the isolation of a sufficient quantity of pure substance for full spectroscopic characterization. The active pheromonal compound was shown to be L-kynurenine (6). It was estimated to be present at a concentration of 1.1 mg 100 ml-1 of urine. Interestingly, that is a hundred or more times higher than the concentration in the ovulated female urine of rainbow or brown trout. The absolute configuration of 6 was determined by Marfey s analysis,40 which involves... 

Subsequently, shallow water collections of Lyngbya majuscula from Puerto Rico and the Dry Tortugas yielded additional supplies of ATX as well as a new congener termed antillatoxin B (Figure 6.10) [149]. The structure of the new metabolite was determined largely by comparison with the spectroscopic data set for ATX, and stereochemistry deduced by Marfey s analysis for L-alanine while the i-N-methyl homophenylalanine was proposed based on nuclear Overhauser effect (nOe) and bioassay results. Substitution of i-N-methyl homo-phenylalanine, an intriguing amino acid of quite rare occurrence in natural products, for i-N-methyl valine... 

SAMPLE Chemistry (Fmoc de ult) Protecting group (Trt defeult) 1 % desired HPLC % desired MALDIMS % desired MALDIMS. diluted %D Marfey s %D HPLC %0 CPAA S oteer molecular species present by ESI-MS or MALDI-MS analysis... 

Figure 4. Distribution of Data from AAA Followed by Marfey s Analysis...

The fungal strain Acremonium sp. MST-MF558a was isolated from a Tasmanian estuarine sediment sample, and based on its rDNA sequence was considered to represent a new species. From the culture broth, a novel family of lipodepsipeptides, acremolides A-D (180-183), was obtained, together with known chaetoglobo-sins. The absolute stereochemistry of amino acid residues in 180-183 was determined using a new C3 Marfey s method for amino acid analysis. Compounds 180-183 were neither cytotoxic in their own right nor... 

The purity of protected amino acids is especially important for the synthesis of longer peptides. Standard techniques such as melting point determination, nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, and optical rotation are effective means of characterization. The optical purity can also be evaluated by high-performance liquid chromatography (HPLC) after derivatization with Marfey s reagent [216,217]. The advanced Marfey method refers to analysis by mass spectrometry after derivatization with Marfey s reagent [218-221]. Purification of side-chain protected amino acids by recrystallization is usually sufficient. 

Bhushan R, Briidcner H. Use of Marfey s reagent and analogs for chiral amino acid analysis assessment and applications to natural prcxiucts and biological systems. J Chromatogr B 2011 879 3148-61. 

Gao et al. reported araplysillin-III (103) and hexadellin C (104) from the sponge Aiolochroia crassa 36). The absolute configuration of the spiroisoxazoline of both alkaloids was determined by CD spectra. The absolute configuration at C-18 of araplysillin-IIl (103) was shown to be l by HPLC analysis according to Marfey s procedure. The configuration of the A, iV,iV-trimethylhomoserine moiety was deduced as L by comparison of the optical rotation with the d- and l- standards. 

Bhushan, R. and Bruckner, H., Marfey s reagent for chiral amino acid analysis A review. Amino Acids, 27, 231, 2004. 

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