Behavior of certain sugars and sugar alcohols in the presence of tetraborates - correlation of optical rotation and compound formation

Abstract

I n t he prese nt investigation, the cha nges in the equilibrium specifi c r otation ca used by t he addi tion of either sodium or potassiu m tetr aborate to solu t ions of D-glucose, D-fru ctose, L-sorbosc, s ucrose, mannitol, a nd sorbi tol have bee n obser ved a nd t he results in tc rpret ed . Measure ments h ave been m ade fo r various conce ntra tions of carbohydrat es with fi xed co nce nt rations of borat c, and for vari ous conce ntr ations of borate wit h fi xcd co nce ntr atio ns of carboh ydratc. It was t hus possible to obser ve independently t he effcct of variatio n in t he co ncentration of eit her carboh ydrate or bor ate. The resul ts indi cate t h at glucose, fru ctose, sor bose, a nd sorbitol for m t hree b orate co mpounds, t hat m a nnitol forms two, a nd s ucr ose one. T he optical rotations of the compo unds ha ve bee n estimaLed, a nd t he co mposition of t hc solutions disc ussed . Exte nsive ta bles have been i nclud ed, givin g t he op tical r otations of t he above-me ntio ned carbohydrates i n the pr esence of sodium a nd potassiu m tet raborat e.

Boron, Lignification and the Origin of Vascular Plants‐a Unified Hypothesis

“…From the research paper of Isbell et al (1948), the reviews of Boeseken (1949) and Zittle (1951), and books of Steinberg (1964) and Davidson (1967), the following information is relevant in a biological context concerning the complexing of borate with compounds containing aV-hydroxyl groups. Of biological importance, principal among these are carbohydrates and o-diphenols.…”

“…Complexes I and III can be formed only with m-hydroxyl pairs and, for complex I in particular, the equilibrium is very much in favour of its formation. Investigations of the equilibrium of mannitol and borate over a wide range of concentrations and pH values indicate that a firm union between the components can be expected under physiological conditions (Isbell et al, 1948;Zittle, 1951). * The degree of complexing with borate can be assessed in several ways including measurements of changes in optical rotation, conductivity and electrophoretic mobility + borate.…”

“…2), a point admitted by Gauch and Dugger (1953) in their first paper advocating this hypothesis. Addition of borate to sucrose solutions does cause a small alteration in optical rotation but addition of sucrose does not appreciably afi'ect the conductivity of solutions of boric acid (Isbell et al, 1948;Steinberg, 1964). It is presumed that a complex of type II ( Fig.…”

Are There Inter‐relations Between the Metabolic Role of Boron, Synthesis of Phenolic Phytoalexins and the Germination of Pollen?

“…Borate ions form complexes with carbohydrates, most readily with those containing m-hydroxyl groups (Isbell et al, 1948;Boeseken, 1949;Zittle, 1951). It is proposed that, in diseased and wounded plants, the alterations in metabolism that result in production of phenolic phytoalexins and other phenolic derivatives are due to localized or systemic sequestration of endogenous borate by formation of complexes with carbohydrates that in healthy, unwounded tissues are not exposed to borate.…”

Temperature dependence of the viscosity of aqueous poly(vinyl alcohol)‐borax solutions

“…In the present work, to elucidate the mechanism of the thickening o f dilute PVA solutions by borax, viscosity measurements have been carried out on dilute solutions with various mole ratios of borax to PVA, in the temperature range 25 to 60OC.…”