The Biosynthesis of Cyclitols

Abstract

A. IntroductionThe term "cyclitol" was coined by Micheel [l], and denotes carbocyclic polyalcohols in which the hydroxy groups are attached to ring carbon atoms. All naturally occurring cyclitols known at present are derivatives of cyclohexane, the most important being the hexahydroxycyclohexanes or inositols.

Enzymatic Synthesis of Streptidine from scyllo-Inosamine*

“…Inososes have not been detected in tissue extracts to our knowledge, although the occurrence of scylloinosose can be inferred wherever jcyZZo-inositol is found (Posternak et al, 1959;Posternak, 1965;Kindi et al, 1966;Candy, 1967). Our earlier suggestion of the involvement of scyZZo-inosose in streptidine biosynthesis (Walker and Walker, 1966) has been given subsequent support by the experiments of Bruton et al (1967), which showed that .m^ZZo-inositol as Well as myoinositol can serve as a precursor of the streptidine moiety of streptomycin in vivo.…”

The oxygen isotope enrichment of leaf‐exported assimilates – does it always reflect lamina leaf water enrichment?

“…(23.5‰ – 0.944 × 27‰)/0.056). Moreover, in that case only pinitol and neither the precursor myo‐inisitol (Kindl et al ., ) present in beech and oak nor the other cyclitol quercitol should be strongly depleted. As a consequence, we can rule out differences in the chemical composition as being responsible for the observed differences in the 18 O enrichment of phloem OM between species – at least based on the comparison between pine, on the one hand, and beech and oak, on the other.…”

Accumulation of cyclitols functioning as compatible solutes in the haptophyte alga Pavlova sp.

“…We therefore investigated whether myo ‐inositol is converted to CHP in Pavlova . Prior studies indicate that the biosynthesis of inositol isomers involves a myo ‐inositol intermediate (Kindl et al . 1966).…”

“…Because the 13 C label incorporated uniformly into each carbon of these CHT and CHP molecules, we speculate that these cyclitols were derived from a single precursor molecule. The most widely occurring cyclitol, myo-inositol, and related compounds are derived from D-glucose; this is most likely common to all organisms (Kindl et al 1966). To further explore this possibility, we carried out 13 C-glucose feeding experiments tracing conversion of glucose to CHT and CHP.…”

“…We therefore investigated whether myo-inositol is converted to CHP in Pavlova. Prior studies indicate that the biosynthesis of inositol isomers involves a myo-inositol intermediate (Kindl et al 1966). Additionally, the inositol 2-dehydrogenase enzyme (EC 1.1.1.18) was previously identified in Bacillus subtilis (Ehrenberg) Cohn (Ramaley et al 1979).…”