Lignans of western red cedar (<i>Thuja plicata</i> Donn). VII. Dihydroxythujaplicatin

MacLean, Harold; MacDonald, B. F.

doi:10.1139/v67-120

Cited by 15 publications

(10 citation statements)

References 5 publications

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“…Depending on the species involved, its formation involves deposition of various metabolites (lignans, flavonoids, tannins, and other substances) into pre-lignified secondary xylem, and these can often account for Ͼ20% of the dry weight of the tissue (22)(23)(24)(25)(26)(27)(28)(29)(30). The composition and amounts of these metabolites can vary from plant to plant, and these determine, to a large extent, the properties of the different woods encountered in the plant kingdom.…”

Section: Resultsmentioning

confidence: 99%

Recombinant Pinoresinol-Lariciresinol Reductases from Western Red Cedar (Thuja plicata) Catalyze Opposite Enantiospecific Conversions

Fujita

Gang

Davin

et al. 1999

Journal of Biological Chemistry

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Although the heartwood of woody plants represents the main source of fiber and solid wood products, essentially nothing is known about how the biological processes leading to its formation are initiated and regulated. Accordingly, a reverse transcription-polymerase chain reaction-guided cloning strategy was employed to obtain genes encoding pinoresinol-lariciresinol reductases from western red cedar (Thuja plicata) as a means to initiate the study of its heartwood formation. (؉)-Pinoresinol-(؉)-lariciresinol reductase from Forsythia intermedia was used as a template for primer construction for reverse transcription-polymerase chain reaction amplifications, which, when followed by homologous hybridization cloning, resulted in the isolation of two distinct classes of putative pinoresinol-lariciresinol reductase cDNA clones from western red cedar. A representative of each class was expressed as a fusion protein with ␤-galactosidase and assayed for enzymatic activity. Using both deuterated and radiolabeled (؎)-pinoresinols as substrates, it was established that each class of cDNA encoded a pinoresinol-lariciresinol reductase of different (opposite) enantiospecificity. Significantly, the protein from one class converted (؉)-pinoresinol into (-)-secoisolariciresinol, whereas the other utilized the opposite (-)-enantiomer to give the corresponding (؉)-form. This differential substrate specificity raises important questions about the role of each of these individual reductases in heartwood formation, such as whether they are expressed in different cells/tissues or at different stages during heartwood development.

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Section: Resultsmentioning

confidence: 99%

Recombinant Pinoresinol-Lariciresinol Reductases from Western Red Cedar (Thuja plicata) Catalyze Opposite Enantiospecific Conversions

Fujita

Gang

Davin

et al. 1999

Journal of Biological Chemistry

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“…Third, lignans such as (-)-plicatic acid 1 and its derivatives in Thuja plicata can accumulate in heartwood in large amount (2)(3)(4)(5)(6)(7)(8)(9)(10). Indeed, when taken together with the tropolones (which are also thought to contribute to the high quality of this wood), these readily solubilized compounds can make up more than 20% of the mass of the heartwood, based on dry weight.…”

Section: Selected Elements Of the Heartwood Arsenalmentioning

confidence: 99%

The 'Abnormal Lignins': Mapping Heartwood Formation Through the Lignan Biosynthetic Pathway

Gang

Fujita

Davin

et al. 1998

ACS Symposium Series

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A significant portion of 'non-lignin' phenolic extractives in heartwood tissues requires solubilization conditions normally used for lignin dissolution. Although they have incorrectly been characterized as 'abnormal' or 'secondary' lignins, their formation and accumulation differs profoundly from that leading to the lignins in three primary ways: first, they are transported through specialized cells (such as ray parenchyma) and are infused into surrounding pre-lignified cells; second, they are formed via distinct biochemical pathways, affording lignan or (iso)flavonoid-derived substances of various molecular sizes; third, their accumulation begins in the pith and over time extends out centrifugally towards the cambial regions, unless formed locally elsewhere as an inducible response. By contrast, lignification results via direct monomer transport from the cytoplasm of a lignifying cell into its polysaccharide-rich cell wall with subsequent polymerization; this process represents the first and final committed step to lignification, being primarily initiated and completed in maturing cell walls not far from the cambial zone. In this study, western red cedar, western hemlock and loblolly pine were examined to establish how their species -specific, non-lignin heartwood substances are biosynthesized. Specific enzymes and genes were obtained for pivotal steps leading to plicatic acid (western red cedar), α-conidendrin (western hemlock) and dihydrodehydrodiconiferyl alcohol and related structures (loblolly pine). In each case, coniferyl alcohol served as the initial precursor, being subsequently metabolized with precise regio-and stereochemical control to first give species-specific lignans from which the 'secondary', or 'abnormal lignins' derive. The results again underscore the need to systematically determine the precise temporal and spatial biochemical processes involved in phenolic coupling, as well as any subsequent metabolic events in planta. These findings pave the way to a full delineation of the temporal, spatial, tissue-and cell-specific events involved in heartwood formation. Ultimately this will offer new strategies for biotechnological manipulation. It will also lead to the adoption of a coherent terminology to define these non-lignin phenolics.

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“…Permanganate oxidation and detection of 3,4-diethoxy-5-methoxy benzoic acid was carried out as previously described (10).…”

Section: Trietlryl Plicatitlaplrtllaler2e ( 4 )mentioning

confidence: 99%

Lignans of western red cedar (Thujaplicata Donn). IX. Plicatinaphthalene

MacLean¹,

MacDonald²

1969

Can. J. Chem.

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The last of nine lignans detectable by thin-layer chromatography in the hot-water soluble extractives of western red cedar (Thujaplicata Donn) heartwood has been determined as 6-hydroxy-2(hydroxy-methyl)-7-methoxy-4-(3′,4′-dihydroxy-5′-methoxyphenyl)-3-naphthoic acid lactone (plicatinaphthalene 2) by spectrometric methods, by degradation studies of derivatives, and by preparation of its trimethyl ether derivative 3 from dehydroanhydropicropodophyllin by opening of the methylenedioxy group with boron trichloride.

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Lignans of western red cedar (Thuja plicata Donn). VII. Dihydroxythujaplicatin

Cited by 15 publications

References 5 publications

Recombinant Pinoresinol-Lariciresinol Reductases from Western Red Cedar (Thuja plicata) Catalyze Opposite Enantiospecific Conversions

Recombinant Pinoresinol-Lariciresinol Reductases from Western Red Cedar (Thuja plicata) Catalyze Opposite Enantiospecific Conversions

The 'Abnormal Lignins': Mapping Heartwood Formation Through the Lignan Biosynthetic Pathway

Lignans of western red cedar (Thujaplicata Donn). IX. Plicatinaphthalene

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