EXTRACTIVE COMPONENTS FROM INCENSE-CEDAR HEARTWOOD (Libocedrus decurrens Torrey) I. OCCURRENCE OF CARVACROL, HYDROTHYMOQUINONE, AND THYMOQUINONE

Abstract

Incense-cedar (Libocedrus decurrens Torrey) trees are indigenous to the Pacific Coast region from Oregon to lower California. While the tree finds limited use in the normal wood-using channels, it is presently the world's most important pencil wood, because of its soft texture and ease of cutting. The recovery of usable lumber stock from incense-cedar is considered low, because of the susceptibility and high incidence of pecky rot, Polyporus amarus, in the heartwood of mature trees. This fungus attacks only the living tree and becomes dormant when the tree is felled. An excellent review on the heartrot of incense-cedar trees is presented by Boyce (1). Interestingly enough, however, the sound heartwood recovered is prized for fence posts, rails, and other uses requiring resistance to decay. No reason appears to have been made as to why the living tree is so susceptible to pecky rot, while the sound heartwood, when exposed to conditions conducive to decay, is so durable. This reputation for durability has not heretofore occasioned any chemical investigations as to the nature of its heartwood extractive components. The present investigation is the first of a series which deals with the isolation and identification of several of its heartwood extractive constituents, some of which are responsible, in part for the decay resistance of incense-cedar.On steam-distilling the chloroform-soluble components obtained from the acetone extract of incense-cedar heartwood, a 2.9 per cent yield of volatile oil was obtained (dry wood basis). Approximately 83 per cent of the volatile oil was soluble in dilute sodium hydroxide and, while predominately phenolic, it was found to contain a small amount of acidic components which appears to be tropolonic in nature. The recovered phenolic oil was fractionally distilled, in vacuo, of which 34 per cent was identified as carvacrol. In addition, a small amount of hydrothymoquinone, 1.08 per cent, was also found to be present among the fractionated products. The neutral fraction contained 21.7 percent of thymoquinone. SUMMARYCarvacrol, hydrothymoquinone, and thymoquinone were identified among the extractive components isolated from incense-cedar heartwood (Libocedms decwrrens Torrey). The amounts of the latter two compounds obtained do not necessarily represent the precise quantity, existing in situ, because the isolation methods employed were found to change, in part, the relative quantities of each.Other procedures, including filter paper chromatography, were developed to indicate that each of these products does occur in the wood as a primary constituent and is not the result of their inter-conversion. Since these three extractive constituents have fungicidal properties, they appear to be partially responsible for the well-known decay resistance of incense-cedar heartwood.Berkeley 4, California

The Chemistry of Decay Resistance and its Decrease with Heartwood Aging in Incense Cedar (Libocedrus decurrensTorrey)

“…During investigations by Zavarin and Anderson (17,18,19) on the chemical identity of the various extractive components present in this heartwood, the decay retarding capacity of each compound was determined in cooperation with the U. S. Forest Products Laboratory, Madison, Wisconsin. During investigations by Zavarin and Anderson (17,18,19) on the chemical identity of the various extractive components present in this heartwood, the decay retarding capacity of each compound was determined in cooperation with the U. S. Forest Products Laboratory, Madison, Wisconsin.…”

Two New Diterpene Phenols from Calocedrus decurrans

“…NMR data was also assigned for compounds 3-5 in Tables 1 and 2, since Obviously, the nature of compounds 1-5 suggests their formation through oxidative coupling reactions involving p-methoxycarvacrol, p-methoxythymol and thymoquinone monomers, that have all been isolated earlier by Zavarin et al [1,2]. Verification of these monomeric components can be elucidated by signals of their isopropyl methine protons as shown for compounds 1-5 in Figure 3.…”

“…Florin., is a native tree in Oregon and California which is perhaps best known for its historical role in the manufacture of wooden pencils. Previous studies have identified carvacrol, thymoquinone, various related p-cymene derivatives and tropolones [1][2][3][4][5][6], although structural data in some cases was inconclusive due to the lack of modern NMR and HRMS techniques. Recent studies have shown the extracts and essential oils from its heartwood have significant antimicrobial activity against Phytophthora ramorum (sudden oak death) [7] and biocidal activity against anthropods of public health importance such as fleas, ticks, and mosquitoes [8].…”

Sodium Metaperiodate Oxidation of Isocarvacrol

“…Natural occurrence of 13 is reported. [10][11][12] The m.p. 10 and spectral data ( 1 H and 13 C NMR) of 13 were identical with those reported in literature.…”

“…[10][11][12] The m.p. 10 and spectral data ( 1 H and 13 C NMR) of 13 were identical with those reported in literature. [11][12][13] The more polar component (21%), a viscous liquid was identified as a ring cleavage product, 7-oxo-5-isopropyl-3-en-2,5-olide 14 on the basis of its spectral data (Table 1) and mechanistic considerations (Scheme 3).…”