Biosynthesis of Cyclic

Guanylate cyclase, the enzyme that catalyzes the biosynthesis of cyclic GMP from GTP, has been shown to be activated in rat-brain slices by HA, resulting in increased accumulation of cyclic GMP . In addition, HA was demonstrated to possess vasodila-... 

Burbott, A. ]., R. Croteau, W. E. Shine, and W. D. Loomis. Biosynthesis of cyclic monoterpenes by cell freee extracts of Mentha piperita. Int Congr Essent Oils (PAP) 6 Allured Publ Corp Oak Park, 111 1974 17 1. 

IV. Biosynthesis of cyclic dlterpenes from trans-geranyl-geranyl pyrophosphate." J. Biol. Chem., 19 % 2kh, 3200-3209. 

Desai, R. S., Kumar, P. and Chilton, W. S. 1996. Indole is an intermediate in the biosynthesis of cyclic hydroxamic acids in maize. Chem. Commun., 1321... 

Macrocyclic diarylheptanoids can be derived from linear ones by oxidative cyclization. This is supported by the fact that in all of the biaryl type representatives the aryl-aryl bond is in meta position relative to both ends of the seven-carbon chain, while in those containing a diarylether bond a meta,para bridging can be identified. This substitution pattern corresponds to activation of the position ortho to the phenolic hydroxy group. Biosynthesis of cyclic diarylheptanoids was investigated by Inoue et al. (84). They fed [1- C] and... 

Recent studies on the mechanism of biosynthesis of cyclic lipopeptide antibiotics have proved that these are systematically synthesized by the multifunctional proteins, non-ribosomal peptide synthetase (NRPS). 

Biosynthesis of cyclic bromo-ethers derived from red algae 02YGK1181. 

Suga, T., Hirata, T., Aoki. T., and Shishibori, T., Interconversion and cyclization of acyclic allyhc pyrophosphates in the biosynthesis of cyclic monoterpenoids in higher plants. Phytochemistry, 25, 2769, 1986. 

A different mechanism was adopted in the biosynthesis of cyclic polyethers such as monensin. These PK-derived polycycles are formed in a cascade fashion with other enzymatic transformations. For example, in the biosynthesis of monensin (Equation 8.2), the cascade polyether formation is triggered by epoxidation of a polyene template [40]. Similar mechanisms can probably be used to make other polyether antibiotics containing tetrahydrofurans and tetrahydropyrans [41]. 

H. Ohkawa, and H. Iwamura (2002). Molecular characterization and chromosomal localization of cytochrome P450 genes involved in the biosynthesis of cyclic hydroxamic acids in hexaploid wheat. Mol. Gen. Genet. 267, 210-217. 

LEIGHTON, V., NIEMEYER, H.M., JONSSON, L.M.V., Substrate specificity of a glucosyltransferase and a IV-hydroxylase involved in the biosynthesis of cyclic hydroxamic acids in Gramineae, Phytochemistry, 1994, 36, 887-892. 

Plant hormone biosynthesis and metabolism are influenced and modified, too, as already mentioned, by a large number of typical secondary plant constituents of quite different structures (Eef. 5, 6). For instance, it has been shown that some oi-disubstituted acetic acid derivatives are active both as antiauxins and as inhibitors of the biosynthesis of cyclic terpenoids. Thus, some more simple model compounds synthesized by ourselves, for example substituted a-phenoxy-isobutyrio acids, are not only competitive auxin inhibitors but they are also able to inhibit both the gibberellin and sterol biosynthesis. The same is true for some well known plant growth retardants, such as CCO or AMO 1618, which are inhibitors of gibberellin biosynthesis both in plants and in Fus ium moniliforme, but at the same time they are inhibiting and modifying also the biosynthesis of steroids in the respective organisms as well as in animal in vitro systems (Eef. 29) ... 

Robinson, D. R. and C. A. West, Biosynthesis of cyclic diterpenes in extracts from seedlings of Ricinus communis L. II. Conversion of geranylgeranyl pyrophosphate into diterpene hydrocarbons and partial purification of the cyclization enzymes. Biochemistry, 9, 80-89 (1970). 

Mangold, K. H., Spener, F. Biosynthesis of cyclic fatty acids. In The Biochemistry of Plants, Vol. 4, Lipids Structure and Function (P. K. Stumpf, ed.), pp. 647-663. Academic Press, New York 1980... 

The biosynthesis of cyclic sesquiterpenes probably includes the formation of enzyme-bound intermediates (Figs. 107 and 108). It is accompanied by the shift of double bonds, hydride ions, etc. The diversity of chemical structures of sesquiterpenes is greater than that of mono-, di-, and triterpenes due to the many different types of cyclizations occuring in this group of secondary products. 

Several pathways exist for the biosynthesis of cyclic carotenoids. Starting materials are the different aliphatic carotenes. From lycopene, for instance, the compounds given in Fig. 137 are formed. The biosynthesis of the different types of ionone rings follows the pathway outlined in Fig. 138. A proton is added to C-2 and a bond is formed between C-1 and C-6. Than a hydrogen atom is eliminated from positions 4, 6, or 18, resulting in the formation of the y- or e-ionone rings, respectively. 

Suga T, Shishibori T, Morinaka H 1980 Preferential participation of linaloyl pyrophosphate rather than neryl pyrophosphate in biosynthesis of cyclic monoterpenoids in higher plants. J Chem Soc Chem Commun 167-168... 

Mohan, R.S., Yee, N.K.N., Coates, R.M. etal, (1996) Biosynthesis of cyclic diterpene hydrocarbons in rice cell suspensions conversion of 9,10-s/n-labda-8( 17),13-dienyl diphosphate to 9P-pimara-7,15-diene and stemar-13-ene. Arch. Biochem. Biophys., 330, 33-47. 

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