Inosose deoxy

The General myo-lnositol and scyllo-Inosamine Pathway. Two distinct cyclitol pathways, which we earlier called Ca (started by myo-inositolphos-phate synthase) and Cb (started by T-deoxy-i cy/to-inosose synthase), are used in the initiation of AGA pathways. Here we will describe the Ca route and the Cb pathway in the paragraph on NEOs (see Section 2.2.2.1.3). The cyclitol pathway in the biosynthetic pathways for STRs, but also for other AGAs such as SPCs, KAS, and FORs and also the mixed type antibiotic HYG-A (see Section 2.2.4.3.1), starts with the formation of myo-inositol in a two-step pathway (Ca) that is not encoded in the itrAtt-clusters. The first step in streptidine biosynthesis (and any other myo-inositol utilising pathway) is the formation of a myo-inositol monophosphate (D-myo-inositol-3-phosphate or L-myo-inositol-1-phosphate) via L-myo-inositol-1-phosphate synthase, which in actinomycetes... 

SfrF04.2 NeoC 430 17039 2-Deoxy-icyZZo-inosose synthase (cyclase)... 

SteK17.24 TobC 386 17039 2-Deoxy-icy//o-inosose synthase (cyclas... 

Formation of the Initial Cyclitol. The first steps of FOR production are the same as in the biosynthesis of STR in short, the first step in FOR biosynthesis is postulated to be the formation of a myo-inositol monophosphate (D-myo-inositol-3-phosphate or L-myo-inositol-1-phosphate) via the cellular l-myo-inositol-1-phosphate synthase as in the STR pathway (Ca pathway see Section 2.2.1.2). As in the itr-Att-clusters, no gene for this enzyme has been found in the/or-cluster. As a second step in FOR biosynthesis the dephosphorylation of D-myo-inositol-3-phosphate via an inositolmonophosphate phosphatase has to follow. A putative gene product with this activity is that of the ForA protein (cf. Tables 2.17 and 2.18). The cyclitol is postulated to be first converted via two enzymes, a cluster-encoded myo-inositol 3-dehydrogenase (ForG member of the GFO/IDH/MocA oxidoreductase family) and the L-glutamine icy//o-3-inosose 3-aminotransferase (ketocyclitol aminotransferase I ForS), to icy//o-inosamine (3-deoxy-3-amino- cy/to-mositol). 

SteO08.22c AprC 384 17039 2-Deoxy-scyllo -inosose synthase,cyclase... 

Aminoglycoside Biosynthesis. The biosynthesis of aminoglycosides has been extensively studied. Probably the most interesting aspect is the biosynthesis of 2-deoxystreptamine, in which the C-l and C-6 of a i> glucose molecule become the C-l and C-2 of 2-deoxysptreptamine by way of the intermediate 2-deoxy-scWfo-inosose. 

According to the Angyal proposals, the cyclohexanepenfo/s are all called quercitols, and these compounds, like the pentahydroxycyclohexanones inososes), are differentiated by trivial prefixes, the same prefix being used for the quercitol and the inosose of the same configuration. These prefixes are shown under the formulas CXXXIX-CXLIV (see p. 190). In the Fletcher-Anderson-Lardy system, these compounds are named as deoxy and keto derivatives, respectively, of inositols. The Angyal names will be... 

Other quercitols have been synthesized by catalytic hydrogenolysis of the corresponding inososes (see p. 180). All the known quercitols are shown, with their names, in formulas CXXXIX-CXLIV according to Angyal and Macdonald s proposals,6 the quercitol of acorn is called (+)-profo-quercitol, and natural viburnitol is named (—)-w 6o-quercitol the corresponding Fletcher-Anderson-Lardy names are (+)-1 -deoxy-mwco-inositol and ( —)-1-deoxy-WM/o-inositol. Synthesis of the four as-yet-unknown diastereomers should not present serious difficulties. 

Deoxy-2-keto-l-O-methyl-mj/o-inositol (3-Deoxy-l -O-methyl -myo-inosose-2) active 236a... 

Deoxy-2-keto-mj/o-inositol (5-Deoxy-mj/o-inosose-2) meso 42... 

CA, Candida antartica CR, Candida rugosa DKR, dynamic kinetic resolution DOIS, 2-deoxy-cyllo-inosose synthase LDH, lactate dehydrogenase THF, tetrahydrofuran. 

Hydrogenation with hydrogen and a metallic catalyst has been used27 to convert mi/o-inosose-2 into mi/o-inositol-2-d, and to obtain methyl 2-deoxy-/3(and a)-D-glucopyranoside-2-d from methyl 2-deoxy-2-iodo-/3-D-glucopyranoside and from methyl 2-deoxy-2-iodo-a-D-mannopyranoside, respectively.28 The equatorially attached... 

Scheme 12. 5-Deoxygenation during the biosynthesis of 2-deoxystreptamine (27 the core moiety of neomycin 25, streptamine 26 is its analog in streptomycin 24) through transamination of the intermediate 2-deoxy-scyl/o-inosose (28). Note that C-5 of glucose becomes C-3 of 26 and 27...

The Weerman degradation was employed in one of the first preparations of dialdoses, namely of n-f/ireo-tetrodialdose, using the diamide of D-glucaric acid as starting material. An inosose has been degraded to a pentodialdose by way of its disulfone and the Nef reaction, transformation of a 6-deoxy-... 

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