3-Guanylic acid

Mushrooms have been investigated with especial reference to shiitake, Lentinus edodes, the flavorful fungus widely used in Chinese and Japanese dishes. While the umami taste is attributed to guanylic acid, lentinic acid 14 (Scheme 6) is converted to lenthionine, 1,2,3,5,6-pentathiacycloheptane 15, a compound with the characteristic shiitake flavor. This complex reaction requires a C-S lyase enzyme.30 Other important flavor compounds are 1,2,4,6-tetrathiacycloheptane 16 (Scheme 6) and 1,2,3,4,5,6-hexathiacycloheptane (not shown). 

GM-C5F—granulocyte macrophage colony-stimulating factor GMP—guanylic acid... 

Chloropurine ribonucleotide and thioinosinic acid also react covalently with GMP reductase, the enzyme that converts guanylic acid to inosinic acid and ammonia [318]. 

The second step in the conversion of inosinic acid to guanylic acid is the aminolysis of xanthylic acid with glutamine by xanthosine-5 -phosphate aminase [65]. This aminase, isolated fromf. coli B, is inhibited allosterically by adenosine and adenylic acid [320], and it is also inhibited by psicofuranine (9-0-D-psicofuranosyladenine) (LXXIV) [284, 321-326], which apparently is not... 

Azathioprine is converted in vivo to thioinosinic acid, which competitively inhibits the synthesis of in-osinic acid, the precursor to adenylic acid and guanylic acid. In this way, azathioprine inhibits DNA synthesis and therefore suppresses lymphocyte proliferation. This effectively inhibits both humoral and cell-mediated immune responses. 

Guanosine5 phosphate (GMP,Guanosine 5 -guanylic acid) 203 Guanylate cyclase 561, 657 Guanylin 548, 561... 

Nucleotides (glutamic acid, guanyl acid, xanthyllic acid)... 

Holy and Sorm (49, 50) observed that RNase T2, like RNase Ti, attacks 9-(/3-D-ribofuranosyl) and 9-(a-L-lyxofuranosyl) derivatives but not 9-(j8-L-ribofuranosyl) and 9-(a-D-lyxofuranosyl) derivatives. Also, like RNase RNase T2 is quite inactive on the phosphodiester bonds of the nucleotide with 2 -0-methyl ribose, such as 2 -0-methyl guanylic acid (96) or 2 -0-methyl cytidylic acid (86). Thus, the action of RNase T2 is in good accord with that of RNase Ti and RNase A on sugar specificity, which may be a common property throughout all RNases, producing 3 -phosphate via 2, 3 -cyclic phosphate. 

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