Mushroom amino acid

Glutamic acid is a component of many proteins, such as those in dairy products, meat, legumes, and mushrooms. However, only the free form of glutamic acid or glutamates has an effect on the glutamate receptors. When bound to other amino acids in a protein, it does not stimulate glutamate receptors. 

In recent years, the use of a-substituted phosphoryl compounds has mushroomed as they have become recognized as useful analogues of a-substituted carboxyl compounds (including the a-amino acids), as well as materials with their own applications. We will begin here by reviewing the well-established approaches toward such materials, specifically the Abramov and Pudovik reactions, including the associated conjugate addition reactions, and then consider the newer approaches toward such compounds. 

Isolated from mushroom Nonprotein amino acid with phytotoxic,... 

COjH >j C02H Japanese mushroom -Clitocybe acromelalga Acromeiic acids A-C -cytotoxic nonprotein amino acids 230... 

Stimulation - excitatory amino acids -headache, confusion, hallucinations Red alga (red tide), Green alga Mushrooms - Amanita family (fly agaric), flat pea [Lathyrus] Kainic acid, domoic acid -concentrated in shellfish, Ibotenic acid, muscarinic acid, (hallucinations) Latthyrism - motor neuron degeneration... 

This mushroom produces the toxin, a-amanitin, a cyclic octapeptide having several modified amino acids and a central purine, which strongly binds to and inhibits RNA pal ii and thereby blocirs elongation. 

Muscaflavin, a yellow pigment from the poisonous mushroom Amanita muscaria has the unusual dihydroazepine-amino acid structure (288) (81LA2164). 

What is most remarkable is that cells can produce proteins with strikingly different properties and activities by joining the same 20 amino acids in many different combinations and sequences. From these building blocks different organisms can make such widely diverse products as enzymes, hormones, antibodies, transporters, muscle fibers, the lens protein of the eye, feathers, spider webs, rhinoceros horn, milk proteins, antibiotics, mushroom poisons, and myriad other substances having distinct biological activities (Fig. 3-1). Among these protein products, the enzymes are the most varied and specialized. Virtually all cellular reactions are catalyzed by enzymes. 

Many small peptides exert their effects at very low concentrations. For example, a number of vertebrate hormones (Chapter 23) are small peptides. These include oxytocin (nine amino acid residues), which is secreted by the posterior pituitary and stimulates uterine contractions bradykinin (nine residues), which inhibits inflammation of tissues and thyrotropin-releasing factor (three residues), which is formed in the hypothalamus and stimulates the release of another hormone, thyrotropin, from the anterior pituitary gland. Some extremely toxic mushroom poisons, such as amanitin, are also small peptides, as are many antibiotics. 

Mushrooms are a source of simple chlorinated amino acids (7), and several new examples are known. Thus, Amanita vergineoides has furnished (2S,4Z)-2-amino-5-chloro-4-pentenoic acid (915) (964), and a full account of the isolation of (2S)-2-... 

Yoshimura H, Takegami K, Doe M, Yamashita T, Shibata K, Wakabayashi K, Soga K, Kamisaka S (1999) a-Amino Acids from a Mushroom, Amanita castanopsidis Hongo, with Growth-Inhibiting Activity. Phytochemistry 52 25... 

The amatoxins are cyclic octapeptides composed only of L-amino acids and containing a sulfoxide group instead of the thioether bridge in phallotoxin. Over 90% of the fatal cases of mushroom poisoning can be traced back to the amatoxins. Wieland et al. 234) have shown that, in addition to the toxins, the death cup contains a low concentration of an antitoxic cyclic decapeptide antamanide 108. 

Natural products that contain the imidazole nucleus have been found in such diverse sources as mushrooms and broiled fish. In the former, the fresh fruiting bodies of Clitocybe acromelalga contain the new amino-acid betaine clithioneine... 

In another thorough flavor study Wu et al.(55) determined both the volatile and nonvolatile flavor compounds found in mushroom blanching water. They used HPLC to determine such non volatile flavor components as sugars, amino acids and nucleotides. The free amino acids were analyzed to determine if they might be involved in any thermal reactions which might produce Amadori compounds or Strecker aldehydes which in turn would produce aroma components. 

The E coli amine oxidase dimer is mushroom shaped with the istaM comprising the first 85 amino acids of each polypeptide chain and the icapi the remaining 640 residues (Figure 11a). 

L-Glu and Asp are sour stimuli in dissociated state, but their sodium salts dissociate on solution and elicit the umami taste. Free L-glutamate is contained in natvu al foods, as shown in Table 2 and contributes to the savory taste of foods as its sodium salt. Ibotenlc and tricholomlc acids (lA and TA) discovered in mushrooms are the derivatives of oxyglutamic acid and are also umami substances (, 5). The umami taste intensity of lA or TA is A to 25 times that of MSG. As these compounds are not amino acids commonly found in an animal system, they have not been used as seasoners. The umami taste or TA-5 -ribonucleotide mixture is much more Intense only MSG, lA or TA. Among 5 -ribonucleotides, 5 -guanylate have synergistic effects in a mixture with This phenomenon is called the synergistic effect of... 

In 1972 Bayer and Kneifel isolated (98) a pale blue compound from A. muscaria containing vanadium, which they named amavadine. They proposed (98,99) that it consisted of a complex of AT-hydroxyimino-a,a -dipropionic acid with in a 2 1 ratio. From a comparison of the EPR spectra of segments of frozen mushrooms with those of vanadyl complexes of various amino acids, it was concluded (100,101) that this proposal was not very likely. However, Krauss et al. (102) synthesized amavadine and compared its EPR properties with the complex extracted from the mushroom and concluded that it was the same. Others were unable to reproduce the synthesis (103), although models analogous to amavadine were reported. The synthesis of the ligand N-hydroxy-a,a -iminodipropionic acid, and related compounds was, however, later confirmed (104-106). The stereochemistry and total synthesis of the vanadium compound of A. muscaria has now been elucidated (107). 

In terms of cultivation parameters and nutrients, the psychotropic species are no different from table mushrooms and other common gilled mushrooms. For that reason, Oss and Oeric s speculations about extra-terrestrial origins of these species clearly belong into the realm of fables. In addition, psilocybin and psilocin are substances that can be derived from tryptophan by means of discemable reactions indeed, the amino acid tryptophan in its free form has been found in a large number of mushroom species. 

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