Shikimic acid structure

Usami Y, Horibe Y, Takaoka I, Ichikawa H, Arimoto M (2006) First Total Synthesis of (-)-Pericosine A from (-)-Shikimic Acid Structure Revision and Determination of the Absolute Configuration of Antitumour Natural Product Pericosine A. Synlett 1598... 

Davis (184) selected a large number of mutants of Escherichia coli requiring two or more aromatic amino acids for growth, and then tested a large number of substances to see if any could relieve the growth inhibition. Success was attained with shikimic acid (215, 268), at that time a relatively obscure natural product. This indicated either that shikimic acid (structure diagram 1) was a true aromatic precursor or that it could readily be transformed into a true precursor. The likelihood that shikimic acid was a true precursor was increased when other mutants were found to accumulate shikimic acid in the medium, from which it could be isolated (184, 185). 

Two cyclitolcarboxylic acids occur in Nature quinic and shikimic acid. Structurally they are closely related to each other, shikimic acid being a dehydroquinic acid their interconversion has been achieved by chemical means. The difficult proof of their constitution was obtained by Fischer and Dangschat through several degradative sequences. ... 

The final example described in this chapter is that done by Schriebej and co-workers. They used a scaffold with multivariant sites derived from shikimic acid. However, the end products of their synthesis were compact, highly functionalized structures reminiscent of alkaloids.34 An objective of this study was to produce a very large number of compounds for miniaturized cell-based assays. In fact, about 2 million compounds were made. 

Isoprenoid structures for carotenoids, phytol, and other terpenes start biosynthetically from acetyl coenzyme A (89) with successive additions giving mevalonate, isopentyl pyrophosphate, geranyl pyrophosphate, farnesyl pyrophosphate (from which squalene and steroids arise), with further build-up to geranyl geranyl pyrophosphate, ultimately to a- and /3-carotenes, lutein, and violaxanthin and related compounds. Aromatic hydrocarbon nuclei are biosynthesized in many instances by the shikimic acid pathway (90). More complex polycyclic aromatic compounds are synthesized by other pathways in which naphthalene dimerization is an important step (91). 

Evans, and later j0rgensen, studied the counterion effect of these Cj-symmetric bis(oxa-zoline)/Cu(II) complexes, and found that the counterion structure dramatically affected the catalytic efficiency, and SbFg- was the best among the anions examined (SbF6>PF6>OTf>BF4) [27,28] (Eq. 8A.15). This cationic bis(oxazoline)/Cu(II) catalyst has been successfully applied to asymmetric synthesis of enr-A1 -tetrahydrocannabinol [29] and enf-shikimic acid [30]. 

Among simple unsaturated carbaaldopyranoses, one of the most well-known examples is represented by MK7607, an effective herbicidal substance isolated from the fermentation broth of Corvularia eragrostidis [38]. Preparation of its unnatural antipode 174 was recently accomplished by Singh who exploited (-)-shikimic acid 169 as the chiral source (Scheme 28) [39]. As with quinic acid, the shikimate structure can be... 

Two main attributes are ascribed to natural shikimic acid the first, of practical nature, is related to its use as a chiral source for asymmetric synthesis, the second, of biochemical prominence, is connected to the key role it exerts in the production of benzenoid rings of natural aromatic amino acids and other important metabolites [45]. The biological relevance of shikimic acid and the challenging nature of its multichiral structure have motivated an active search for the development of viable asymmetric syntheses of this compound and novel structural variants [46],... 

Pericosine B, a secondary metabolite produced by a strain of Periconia bissoides [48], proved to be an interesting target compound due to its significant antitumoral activity. From a structural point of view, pericosine B (201, Scheme 33) can be considered as an unsaturated carbauronic acid or an hydroxylated shikimic acid derivative. 

Even the structural material of plants, lignin, comes from the shikimic acid pathway. Lignin—from which wood is made—has a variable structure according to the plant and the position in the plant. A typical splinter is shown here. 

The first two of these pathways were for many years generally postulated, on the basis of structural relations among various natural products and by analogy with known laboratory reactions they received experimental support later. The last pathway was discovered by B. D. Davis in his work with nutritionally deficient, microbial mutants. However, even earlier, when the structures of quinic acid (VII) and shikimic acid were established, their possible functions as intermediates in the biosynthesis of aromatic... 

It has been noted that the chemical diversity of plant phenolics is as vast as the plant diversity itself. Most plant phenolics are derived directly from the shikimic acid (simple benzoic acids), shikimate (phenylpropanoid) pathway, or a combination of shikimate and acetate (phenylpropanoid-acetate) pathways. Products of each of these pathways undergo additional structural elaborations that result in a vast array of plant phenolics such as simple benzoic acid and ciimamic acid derivatives, monolig-nols, lignans and lignin, phenylpropenes, coumarins, stilbenes, flavonoids, anthocyanidins, and isollavonoids. 

H]shikimic acid were exclusively at C-2 and C-7, it followed that the biosynthesis of iodinin (135), and most probably other phenazines, was according to pattern (136) and not pattern (137). This accords with the structures of other naturally occurring phenazines like the griseoluteins, e.g. griseolutein A (140). 

Another C-C-C-X fragment is shikimic acid-derived 4,5-epoxy-3-hydroxycy-clohex-l-ene-l-carboxylic acid [270]. The latter can be bound onto an amino group which is bound to TentaGel via a Gysen Linker (367) [322]. Subsequent esterification with alkyl or aryl nitrone acids according to Tamura et al. [323] was concurrent with [2 -i- 3]-cycloadditions to the allylic double bond. As a result, tricyclic lactones (370) were obtained, which could readily be modified in many ways to yield a wide variety of polyfunctional structures (Scheme 77). 

Fig 2.5 Showing structure of Anthranilic acid and Shikimic acid. 

Flavonoids are coloured substances and occur as pigments in plants. The chemical structure is built from an acetate-derived component and a segment from the shikimic acid biosynthetic pathway. Knowledge of the... 

The structural and configurational studies of quinic acid (1) by Fischer and Gerda Dangschat were extended during the Basle period to shikimic acid (2), the trihydroxycyclohexenecarboxyhc acid first isolated from the Chinese star anise by Eykman in 1885. This acid was first proved to be a... 

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