Thujin, a novel lactone isolated from the discolored heartwood of Thuja plicata Donn.

Abstract

. 66, 51 (1988).The chemical structure of a novel lactone isolated from the discolored heartwood of living western red cedar (WRC) (Thuja plicara Donn.) trees has been determined as 3,3,4,7,7,8-hexamethyl-2,6-dioxa-I,5-anthracene-dione, and given the trivial name thujin (1). The isolation, purification, and determination of the structure were carried out by a combination of chemical, chromatographic, and spectroscopic methods.LEHONG JIN, JACK W. WILSON et ERIC P. SWAN. Can. J. Chem. 66, 51 (1988) On a dttermink que la structure chimique d'une nouvelle lactone, qui a CtC isolke du bois dur dtcolort de ckdres rouges de I'ouest (cro) (Thuja plicata Donn.), est l'hexamtthyl-3,3,4,7,7,8 dioxa-2,6 anthracknedione-l,5 et que son nom trivial est thujine (I). On a isolk et purifit le produit et on a dttermint sa structure en faisant appel i une combinaison de mtthodes --chihiques, chromatographiques et spectroscopiques.[Traduit par la revue] Introduction During the past three decades, the large-scale chemical investigation of western red cedar (WRC) (Thuja plicata Donn.) heartwood extractives has led to identification of more than a dozen biologically active phenolic compounds (1). These heartwood extractives can be separated readily into volatile and nonvolatile fractions by steam distillation. The volatile fraction consists partly of compounds that are tropolone derivatives, the thujaplicins. The nonvolatile WRC heartwood extractives are mainly lignans (2-12). WRC is recognized as one of the world's most durable woods. It has long been understood from chemical and biological studies that the above two major groups of compounds in WRC heartwood extractives give the wood its durability. It is observed, however, that in certain areas of British Columbia (B.C.) there is a serious WRC heartwood decay problem, especially in living mature and over-mature trees. Questions arise on the biological roles of WRC heartwood extractives in response to microorganism attacks in living trees. In this study, a comparison of differences in extractive composition between healthy and discolored heartwood within the same growth zones in the tree was made. The discoloration of healthy wood was due to infection by microorganism attacks. We now report a novel lactone compound isolated from discolored heartwood extractives that was not present in healthy WRC heartwood extractives. Associated biological tests (13) in this study positively demonstrated that this lactone compound was a biodegradation product of the thujaplicins during infection by a fungus, Sporothrix sp., in the heartwood of a once living WRC tree.

UPLC-MS-ELSD-PDA as a Powerful Dereplication Tool to Facilitate Compound Identification from Small-Molecule Natural Product Libraries

“…Compound 4, with a MW of 300 as indicated by its positive-ion ESIMS (Figure 2f) and UV absorptions at λ max 232, 285, and 326 nm, was likely to be the aromatic lactone thujin, known to occur in Thuja plicata. 29 Compounds 6 and 7, with MWs of 318 and 336, respectively, deduced from their ESIMS (Figure 2g and h), were inferred as being diterpenoids, since these compounds are common in T. occidentalis. 25,30−33 In particular, compound 5, with a MW of 354 (Figure 2i), was of interest because this MW did not match any of the previously reported natural lignans or diterpenoids found in a search of the Dictionary of Natural Products online database (Chapman Hall/CRC) and SciFinder (Chemical Abstracts Service).…”

Chemical Compositions and Enantiomeric Distributions of Foliar Essential Oils of Chamaecyparis lawsoniana (A. Murray bis) Parl, Thuja plicata Donn ex D. Don, and Tsuga heterophylla Sarg.

“…The heartwood of T. plicata has been shown to be a source of tropone monoterpenoids [27][28][29][30][31] and lignans [32][33][34][35][36][37][38][39][40], and the dilactone thujin [41], while the bark and aerial parts have yielded diterpenoid derivatives [42,43]. There have been several investigations on the foliar essential oil compositions of T. plicata growing wild in western North America [44,45], cultivated in Poland [46,47], cultivated in Serbia [48], and growing wild in Idaho, USA [49].…”

“…There are two separate ranges of T. plicata, a Coast-Cascade portion from southeastern Alaska (56°30′ N) to northwestern California (40°30′ N), and a Rocky Mountain section from British Columbia (54°30′ N) to Idaho and Montana (45°50′ N) (Figure 4) [26]. The heartwood of T. plicata has been shown to be a source of tropone monoterpenoids [27][28][29][30][31] and lignans [32][33][34][35][36][37][38][39][40], and the dilactone thujin [41], while the bark and aerial parts have yielded diterpenoid derivatives [42,43]. There have been several investigations on the foliar essential oil compositions of T. plicata growing wild in western North America [44,45], cultivated in Poland [46,47], cultivated in Serbia [48], and growing wild in Idaho, USA [49].…”