Biosynthetic pathway from

Figure 6.10 Biosynthetic pathways from isopenicillin N to penicillin G and cephalosporin C. Some strains have the ability to convert deacetylcephalosporin C into cephamycin C.

Many phytotoxic compounds produced by higher plants are phenolic compounds. Several of these have been implicated in allelopathy. Based on the biosynthetic pathway from which they are derived, phenolic compounds produced by higher plants fall into two general categories 1) terpenoid phenolic compounds derived from five... 

Figure 1. The biosynthetic pathway from tyrosine to melanin (according to Hearing and Tsukamoto, 1991 Tsukamoto et al., 1992). Tyrosinase catalyzes three different reactions in this pathway (1, 2, 3). The reaction catalyzed by the product of TRP-2, DOPAchrome tautomerase, is indicated by 4. DOPA = 3,4-dihydroxyphenylalanine DHICA = 5,6-dihydroxyin-dole-2-carboxylic acid DHI = 5,6-dihydroxyindole.

It has, thus, been demonstrated that redirecting the poly(3HB) biosynthetic pathway from the cytoplasm to the plastid resulted in an approximate 100-fold increase in poly(3HB) production [24]. However, it must be kept in mind that the rate of poly(3HB) biosynthesis in A thaliana leaves was relatively low, since poly(3HB) accumulated progressively over 40-60 days to reach 10-14% of the dry weight, whereas synthesis of starch can reach 17% dry weight for a 12 h photoperiod and seed storage lipids can reach 8% dry weight per day. 

The biosynthetic pathway from a lycopodine derivative to serratinine 4 was proposed previously (a) Inubushi Y, Ishii H, Yasui B, Harayama T (1966) Tetrahedron Lett 7 1551 (b) Inubushi Y, Ishii H, Yasui B, Harayama T (1968) Chem Pharm Bull 16 101 (c) the references in (a) and (b) both have the incorrect stereocenter at C4. This was not established unambiguously until a crystal structure of a derivative was obtained see [4c]... 

Figure 7. Biosynthetic pathway from / -glucogallin to pentagalloylglucose. The galloyl residue introduced in each individual step is marked by an asterisk as indicated by the dashed arrow, the enzyme catalyzing the step from tri- to tetragalloylglucose has not yet been isolated. /3G, / -Glucogallin Glc, glucose.

Alkaloids can be classified in the terms of their (1) biological and ecological activity (2) chemical structures and (3) biosynthetic pathway. From the point of... 

There are a number of studies on the biosynthesis of various pteridines, i.e., xanthopterin (65), isoxanthopterin (67), erythropterin (73), leucopterin (68), and pterin (62) (509-511). The most important intermediate of the proposed biosynthetic pathway from guanosine triphosphate (GTP) (604) seems to be di-hydroneopterin triphosphate (H2-NTP) (605), however, because evidence has recently been accumulated indicating that pteridines such as biopterin (70), sepiapterin (81), and drosopterins (87) are synthesized from GTP (604) by way of H2-NTP (605) (Scheme 76) (5/2). 

Scheme 30 The overall biosynthetic pathway from tyrosine to morphine...

The further biosynthetic pathways from 3-phos-phoglycerate to the myriad amino acids, nucleotides, lipids, and miscellaneous compounds found in cells are complex and numerous. However, the basic features are relatively simple. Figure 17-11 indicates the origins of many substances including the 20 amino acids present in proteins, nucleotides, and lipids. Among the additional key biosynthetic precursors that can be identified from this chart are glucose 6-phosphate, pyruvate, oxaloacetate, acetyl-CoA, 2-oxoglutarate, and succinyl-CoA. 

Glutamate Dehydrogenase and Glutamate 1397 1. Biosynthetic Pathways from Serine... 

Figure 24-22 Abbreviated biosynthetic pathways from 8-aminolevulinate to heme proteins, corrins, chlorophylls, and related substances.

In conclusion, the biosynthetic pathway from a squalene-like intermediate to the Daphniphyllum alkaloids must be acceptable (Schemes X, XI, and XIII) although the specific degradation studies have not been completed. 

Figure 2. The GA biosynthetic pathway from, MVA to GAlsraldehyde. This pathway is found in the fungus Gibberella fujikuroi and higher plants...

Advances in ethylene biochemistry and physiology have preceded along a number of fronts. Firstly the biosynthetic pathway from methionine to ethylene has been further clarified and intermediates identified. Secondly some progress has been made in recognising two possible receptor sites which are inhibited by Ag ions and C0 , respectively. Thirdly the localization of ethylene production has been shown to be associated with membranes in studies with protoplasts. 

In the intervening 13 years the subject has expanded dramatically over 60 compounds are now classified as Erythrina alkaloids, and the structures of most of these have been deduced from a combination of mass spectral fragmentation analysis, H-NMR spectral interpretations, and chemical correlations with alkaloids of known structures. Some unusual alkaloids have been obtained from certain Cocculus species and a new, as yet small, subgroup, the Homoerythrina alkaloids, has been recognized. The biosynthetic pathway from tyrosine through the aromatic bases to the ery-throidines has been elucidated, and some significant advances have been made in methods of total synthesis. Reviews of the Erythrina alkaloids since 1966 have appeared (3-6). 

FIGURE 3.1 The biosynthetic pathway from chorismate to L-phenylalanine in Escherichia coli K12. The mnemonic of the genes involved are shown in parentheses below the enzymes responsible for each step. Compound 1 is L-phenylalanine, 2 is chorisimic acid, 3 is prephenic acid, and 4 is phenylpyruvic acid. 

In the late 1990 s, a breakthrough in biosynthesis was reached based on the finding that benzoxazinone and tryptophane biosynthesis have a formal branch point, and indole is a precursor of the benzoxazinones.18 The biosynthetic pathway from indole as the precursor of the benzoxazinone moiety was elucidated both on the levels of the responsible gene cluster discovered and the corresponding enzymes.23 The stepwise oxidation of indole with molecular oxygen by means of... 

DE LUCA, V., BALSEVICH, J TYLER, R.T., EILERT, U PANCHUK, B.D., KURZ, W.G.W., Biosynthesis of indole alkaloids Developmental regulation of the biosynthetic pathway from tabersonine to vindoline in Catharanthus roseus. J. Plant Physiol., 1986,125, 147-156. 

Figure 4. Biosynthetic pathway from chorismate to enterobactin showing nature of the class I and class II mutations in Salmonella typhimurium LT-2...

Figure 21 Aflatoxin biosynthetic pathway from hexanoyl CoA to versicolorin B.

Figure 22 Aflatoxin biosynthetic pathway from versicolorin B to aflatoxins B-i and Gi.

The biosynthetic pathway from SA into L-Phe [69, 70] is shown in Fig. 8.15. The synthesis of chorismate (CHA), the common intermediate in the biosynthesis of the aromatic amino acids, requires an extra equivalent of PEP, which limits the yield of L-Phe from glucose to 0.30 mol mol-1 if PEP is not conserved [91]. The further transformation of CHA into phenylpyruvic acid (PPY) suffers from inhibition by L-Phe and is also subject to transcriptional control [69, 92]. The final step is a reductive amination of PPY into L-Phe with consumption of l-G1u. 

Figure 4. Possible biosynthetic pathway from dietary steroids to a-ecdysone.

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