l-2-Oxalylamino-3-aminopropionic acid,an isomer of Lathyrus sativus neurotoxin

The first chemical synthesis of l-2-oxalylamino-3-aminopropionic acid, an isomer of the Lathyrus sativus neurotoxin, is described. Studies on its biological properties are reported. Experiments with l-3-[¹⁴C-oxalyl]amino-2- aminopropionic acid show that the amount of 2-oxalylamino isomer detectable in seed extracts can be accounted for by rearrangement which occurs during isolation.     

Isolation and identification of (2S)-2-amino-5-chloro-4-hydroxy-5-hexenoic acid from anAmanita of the sectionRoanokenses (Amanitaceae)

A chlorine-containing non-protein amino acid which was recently discovered from the fruit bodies ofAmanita gymnopus (2S)-2-amino-5-chloro-4-hydroxy-5-hexenoic acid, was isolated and crystallized for the first time from the fruit bodies of an unknown member ofAmanita belonging to the sectionRoanokenses, subsectionSolitariae. The results of elementary analyses, determination of optical rotations,¹H- and¹³C-NMR-spectra, and some chemical reactions supported an earlier proposed structure.Part 24 in the series Biochemical studies of nitrogen compounds in fungi. for Part 23, see Hatanaka, S. I. et al. 1994. this journal35: 391–394.     

Clithioneine,an amino acid betaine from clitocybe acromelalga

A new amino acid betaine, clithioneine, was isolated from a poisonous mushroom Clitocybe acromelalga, and its structure was established on the basis of spectral analyses and chemical degradation studies.     

l-3-(3-carboxyfuran-4-yl)alanine,a new amino acid from the mushroom Phyllotopsis nidulans

A new amino acid has been discovered in uncombined form in extracts of the fruiting bodies of the mushroom, Phyllotopsis nidulans. Chemical and spectroscopic data support formulation of the structure as l-3-(3-carboxyfuran-4-yl)alanine.     

Ds-erythro-2-amino-4-ethoxy-3-hydroxybutanoic acid from the fruiting bodies of the edible mushroom,Lyophyllum ulmarium

A new β-hydroxy amino acid isolated from the fruiting bodies of Lyophyllum ulmarium was identified as D_s,-erythro-2-amino-4-ethoxy-3-hydroxybutanoic acid by chemical degradation and spectroscopic analyses.     

ds-erythro-2-amino-3,4-dihydroxybutanoic acid,a constituent in the edible mushroom,lyophyllum ulmarium

An unusual amino acid occurring in the fruiting bodies of Lyophyllum ulmarium was identified as d_s-erythro- 2-amino-3,4-dihydroxybutanoic acid, which is a compound found for the first time in biological materials.     

(2S)-2-Amino-5-chloro-4-hydroxy-5-hexenoic acid,a new chloroamino acid,and related compounds fromAmanita gymnopus

Combining different chromatography systems, unusual nonprotein amino acids were isolated and unequivocally identified from a small amount (less than 100 g fresh weight) ofAmanita gymnopus fruit body. Without obtaining crystals of these amino acids, on the basis of¹H-NMR determination, high resolution mass spectrometry, chlorine analysis and oxidation with L-amino acid oxidase, one of them proved to be a new chloroamino acid, (2S)-2-amino-5-chloro-4-hydroxy-5-hexenoic acid (G2). The other three were (2S)-2-amino-5-hexenoic acid (G1), (2S)-2-amino-4,5-hexadienoic acid (G3) and (2S)-2-amino-5-hexynoic acid (G4). Amino acid (G1) was also encountered for the first time in natural products. Amino acid (G3) has been reported from several kinds of fungi belonging toAmanita, subgenusLepidella. The occurrence of amino acid (G4) was already reported fromCortinarius claricolor.Part 23 in the series Biochemical studies of nitrogen compounds in fungi. Part 22, Hatanaka, S. I. et al. 1985. Trans. Mycol. Soc. Japan26: 61–68.     

2-amino-4-acetylaminobutyric acid, 2,4-diaminobutyric acid and 2-amino-6N-oxalylureidopropionic acid (oxalylalbizziine) in seeds of acacia angustissima

A new amino acid previously detected in 17 species of Acacia has been isolated from seeds of Acacia angustissima and identified as oxalylalbizziine. These seeds also contain more than 6% dry weight of 2-amino-4-acetylaminobutyric acid, which has not been reported previously in a legume, and lower concentrations of 2,4-diaminobutyric acid.     

A toxic amino acid, 2(S)3(R)-2-amino-3-hydroxypent-4-ynoic acid from the fungus Sclerotium rolfsii

An amino acid, lethal to New Hampshire chickens (LD₅₀, 150 mg/kg) was isolated from dried sclerotia of the fungus Sclerotium rolfsii (Sacc.). Purification of the rather unstable compound was effected on a cation exchange column by means of displacement chromatography and the amino acid was crystallised from 80% methanol. A structure was assigned to the compound on the basis of available chemical and physical data, namely 2(S),3(R)-2- amino-3-hydroxypent-4-ynoic acid. Confirmation of this structure was gained by direct and indirect synthetic procedures.     

2(S),3(S)-3-hydroxy-4-methyleneglutamic Acid from Gleditsia caspica

A new natural product, 2(S),3(S)-3-hydroxy-4-methyleneglutamic acid (G3) has been isolated from seeds of Gleditsia caspica. The structure has been established by chemical and spectroscopic methods. Catalytic reduction of G3 yields 2(S),4(S)-4-methylglutamic acid and a new amino acid, 2(S),3(S),4(S)-3-hydroxy-4-methylglutamic acid. Ozonolysis of G3 followed by oxidation gives 2(S),3(R)-3-hydroxyaspartic acid. The S- (or l-) configurations at C₂ in G3 and in 2(S),3(S),4(S)-3-hydroxy-4-methyglutamic acid and the S-configurations at C₃ for G3 and 2(S),3(S),4(S)-3-hydroxy-4-methylglutamic acid and at C₄ for 2(S),3(S),4(S)-3-hydroxy-4-methylglutamic acid are inferred from the configurations at C₂ in 2(_S),4(_S)-4-methylglutamic acid and at C₂ and C₃ in 2(S),3(R)-3-hydroxyaspartic acid. The seeds also contain appreciable quantities of 2(S),3(S),4(R)-3-hydroxy-4-methylglutami c acid (G1) and 2(S),4(R)-4-methylglutamic acid.     

Tetrahydrolathyrine: A new amino acid from seeds of Lonchocarpus costaricensis

A new non-protein amino acid, tetrahydrolathyrine (2(S)-3(2-amino-1,4,5,6- tetrahydropyrimidin-4-yl)alanine), has been isolated from seeds of Lonchocarpus costaricensis.     

Isolation of (2S,4R)-2-amino-4-methyl-hex-5-enoic acid,a nonprotein amino acid,as an allelochemical from the fruiting bodies of Boletus fraternus Peck.

The mushroom Boletus fraternus Peck. shows allelopathy and suppresses the growth of broad leaf plants in nature. According to a bioassay-guided fractionation of the fruiting body of the fungus, a rare nonprotein amino acid was isolated as a major allelochemical. The chemical structure of the compound was determined to be (2S,4R)-2-amino-4-methyl-hex-5-enoic acid (5-dehydrohomoleucine) by analysis of ¹H- and ¹³C-nuclear magnetic resonance spectra and comparison with data from the literature. The allelochemical caused 50% inhibition of lettuce seedling radicle growth at a concentration of 34 ppm (w/v). Further, since radicle growth was directed away from the filter paper to prevent contact with the allelochemical at concentrations higher than 300 ppm (w/v), the fungus may use the allelochemical to protect its immediate environment from contamination by other plants.     

N-glucosyl-1H-indole derivatives from Cortinarius brunneus (Basidiomycetes)

Two new N-glucosylated indole alkaloids were isolated from fruiting bodies of the basidiomycete Cortinarius brunneus (Pers.) Fr. The structures were elucidated by means of the spectroscopic data. Additionally, the very recently reported compounds N-1-beta-glucopyranosyl-3-(carboxymethyl)-1H-indole (3) and N-1-beta-glucopyranosyl-3-(2-methoxy-2-oxoethyl)-1H-indole (4) could be detected. Compound 3 is the N-glucoside of the plant-growth regulator 1H-indole-3-acetic acid (IAA), but, in contrast, it does not exhibit auxin-like activity in an Arabidopsis thaliana tap root elongation assay.     

Occurrence,structure and synthesis of 3-(N-Methylamino)glutaric acid,an amino acid from Prochloron didemnii

3-(N-Methylamino)glutaric acid has been identified as a new free amino acid in extracts from Prochloron didemnii (Lewin), a unique prokaryotic algal symbiont associated with certain didemnid ascidians. Its structure was established by elucidation of the mass spectra of its TMSi and other derivatives and confirmed by synthesis.     

Erythro-γ-hydroxyhomo-L-arginine: An amino acid from seed of Lonchocarpus costaricensis, and its preferential interaction with borate

A new non-protein amino acid, erythro-γ-hydroxyhomo-L-arginine has been isolated from seed of Lonchocarpus costaricensis by exploiting its property of interacting with borate ions. For structural comparisons, threo-γ-hydroxyhomo-L-arginine was isolated from seed of Lathyrus tingitanus and erythro-γ-hydroxyarginine from Vicia unijuga by novel procedures. The reasons for the interaction of borate with the erythro- but not the threo-forms of these amino acids are discussed.     

2,4-Diamino-3-methylbutanoic acid,a novel amino acid in root nodule hydrolysates from Lotus tenuis

The novel amino acid 2,4-diamino-3-methylbutanoic acid has been identified in nodules formed by two strains of Rhizobium bacteria on Lotus tenuis roots. Retention time measurements on a Chirasil-Val capillary column suggest it is present as the (2R,3S)-enantiomer. Several isomeric diamino acids were synthesized for comparative studies.     

Azetidine-2-carboxylic acid derivatives from seeds of Fagus silvatica L. and a revised structure for nicotianamine

2(S),3′(S)-N-(3-Amino-3-carboxypropyl)azetidine-2-carboxylic acid and 2(S),3′(S),3″(S)-N-[N-(3-amino-3-carboxypropyl)-3-amino-3-carboxypropyl]azetidine-2-carboxylic acid have been isolated from seeds of Fagus silvatica L. (beechnuts). The structures have been established by PMR- and ¹³C-NMR-spectroscopy and by synthesis from l-azetidine-2-carboxylic acid. The second of the new amino acids is identical with nicotianamine. previously isolated from Nicotiana tabacum but assigned a different formula. The ring opening reactions of azetidine-2-carboxylic acid in neutral solution have been studied and the chemical and possibly biochemical precursor role of this amino acid for various amino acids including the two new ones described here, nicotianine [N-(3-amino-3-carboxypropyl)nicotinic acid] and methionine is discussed.     

An improved synthesis of (2S, 4S)‐ and (2S, 4R)‐2‐amino‐4‐methyldecanoic acids: assignment of the stereochemistry of culicinins

An improved synthesis of (2S, 4S)‐ and (2S, 4R)‐2‐amino‐4‐methyldecanoic acids was accomplished using a glutamate derivative as starting material and Evans' asymmetric alkylation as the decisive step. The NMR data of the two diastereomers were measured and compared with those of the natural product. As a result, the stereochemistry of this novel amino acid unit in culicinins was assigned as (2S, 4R). Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.     

Distribution of saccharopine and 2-aminoadipic acid in higher plants

Saccharopine and 2-aminoadipic acid have been identified in eleven plant species belonging to nine families. The amino acids have been isolated from green parts of the plants using ion-exchange chromatography and preparative high voltage electrophoresis, and in three cases the identification was supported by mass spectroscopy. Mild conditions were used during the isolation to avoid lactamization, and the contents of saccharopine and 2-aminoadipic acid have been determined semiquantitatively. The significance of the occurrence of the two amino acids with regard to lysine metabolism is briefly discussed.     

Acide 2(R)-amino-3-butenoique (vinylglycine) dans les carpophores de Rhodophyllus nidorosus

2(R)-amino-3-butenoic acid (vinylglycine), the simplest β,γ-unsaturated α-amino acid, has been isolated from the mushroom Rhodophyllus nidorosus (Fr.) Quél. The amino acid occurs as partly racemized d-form. The structure has been confirmed by comparison with synthetic material.