Coniferin

A beta-glucosidase from lodgepole pine xylem specific for the lignin precursor coniferin.[Pubmed: 7724669]

Plant Physiol. 1995 Feb;107(2):331-9.

Coniferin, the glucoside of the monolignol coniferyl alcohol, accumulates to high levels in gymnosperms during spring-cambial reactivation. A cinnamyl alcohol glucoside/beta-glucosidase system is thought to play a key role in lignification by releasing the monolignol aglycones. Investigation of such an enzyme system in the xylem of Pinus contorta var latifolia Engelm. revealed two major beta-glucosidases.
METHODS AND RESULTS:
One efficiently hydrolyzed the native substrate, Coniferin, and the other was more active against synthetic glucosides. The Coniferin beta-glucosidase was purified to apparent homogeneity using anion exchange, hydrophobic interaction, and size-exclusion chromatography. The apparent native molecular weight was estimated to be 60,000. A dominant 28-kD protein and a minor 24-kD protein were detected in the purified preparation following sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Immunological evidence from polyclonal antibodies directed against the synthetic N-terminal peptide of the 24-kD protein suggested that the native protein is a dimer of 28-kD subunit size.
CONCLUSIONS:
The N-terminal sequence showed that Coniferin beta-glucosidase has high homology to known plant beta-glucosidases. Coniferin, syringin, and a synthetic Coniferin analog were preferred substrates for the Coniferin beta-glucosidase. In situ localization using the chromogenic Coniferin analog showed the exclusive presence of beta-glucosidase activity in the differentiating xylem, similar to peroxidase activity.

Study of Anti-oxidation Effects of Extracts of Balanophora Involucrate and Trans-Coniferin.[Reference: WebLink]

Journal of China Three Gorges University, 2009, 31(3):99-101.

METHODS AND RESULTS:
To study the anti-oxidation effect of extracts of Balanophora involucrate and trans-Coniferin,using the methods of DHHP to study the anti-oxidation effect of extracts of Balanophora involucrate and trans-Coniferin.When the concentration of the extracts of Balanophora involucrate is 3 mg/mL,the absorbency is the least;other concentrations can definitly eliminate the DPPH free radical.
CONCLUSIONS:
The conclusion is that both the extracts of the Balanophora involucrate and trans-Coniferin have anti-oxidation effects.

Proton-dependent coniferin transport, a common major transport event in differentiating xylem tissue of woody plants.[Pubmed: 23585651]

Plant Physiol. 2013 Jun;162(2):918-26.

Lignin biosynthesis is an essential physiological activity of vascular plants if they are to survive under various environmental stresses on land. The biosynthesis of lignin proceeds in the cell wall by polymerization of precursors; the initial step of lignin polymerization is the transportation of lignin monomers from the cytosol to the cell wall, which is critical for lignin formation. There has been much debate on the transported form of the lignin precursor, either as free monolignols or their glucosides.
METHODS AND RESULTS:
In this study, we performed biochemical analyses to characterize the membrane transport mechanism of lignin precursors using angiosperms, hybrid poplar (Populus sieboldii × Populus grandidentata) and poplar (Populus sieboldii), as well gymnosperms, Japanese cypress (Chamaecyparis obtusa) and pine (Pinus densiflora). Membrane vesicles prepared from differentiating xylem tissues showed clear ATP-dependent transport activity of Coniferin, whereas less than 4% of the Coniferin transport activity was seen for coniferyl alcohol. Bafilomycin A1 and proton gradient erasers markedly inhibited Coniferin transport in hybrid poplar membrane vesicles; in contrast, vanadate had no effect. Cis-inhibition experiments suggested that this transport activity was specific for Coniferin. Membrane fractionation of hybrid poplar microsomes demonstrated that transport activity was localized to the tonoplast- and endomembrane-rich fraction.
CONCLUSIONS:
Differentiating xylem of Japanese cypress exhibited almost identical transport properties, suggesting the involvement of a common endomembrane-associated proton/Coniferin antiport mechanism in the lignifying tissues of woody plants, both angiosperms and gymnosperms.