Y-Thujaplicin

Arizona yielded (3-thujaplicin and nootkatin as major components along with lesser amounts of y-thujaplicin [241] and p-thujaplicinol. At a higher taxonomic level, two subspecies of C bakeri Jepson (subsp. bakeri and subsp. mattewsii Wolf), gave identical profiles consisting of P-thujaplicin and nootkatin. 

Cycloheptanes.— The C-1—C-2 bond in -y-thujaplicin is essentially single, Co"-/3-thujaplicin-amine complexes have been described, and thermodynamic data on the U -/3-thujaplicin complex have been calculated. The biomimetic cyclization of the silyl enol ether (191) to karahanaenone (192), using methyl-aluminium bis(trifluoroacetate) is almost quantitative (192) is also synthesized by thermolysis followed by desilylation of the silyl enol ether (193) which is readily available from l-bromo-2-methyl-2-vinylcyclopropane and isobutyraldehyde. Dehalogenation of 3-bromo-l-iodo-3-methylbutan-2-one with Zn-Cu couple on alumina in the presence of isoprene yields (192) and minor amounts of the isomers (194) and (195) however, dehalogenation with Fc2(CO)9 favours (195). Acetolysis of karahanaenol tosylate yields anticipated p-menthane derivatives and no filifolene. ... 

The substituted cycloheptane monoterpenes, also called tropones. Eu-carvone 60, nezukone (4-isopropyl-2,4,6-cycloheptatrienone) 61 and y-thujaplicin 62 (Structure 4.14) most probably arise by an unknown ring expansion of the cyclohexane skeleton. 

Measurement of activation energy and entropy has not distinguished between antara-antara Cope rearrangement and other concerted processes in the photochemical rearrangement of y-thujaplicin O-methyl ether to the bicyclohep-tadienones (157) and (158).255 The hexatriene-cyclohexadiene disrotatory elec-... 

Tropolone monoterpenes include the antifungals (1- and y-thujaplicin (4- and 5-isopropyltropolones, respectively, tropolone being 2-hydroxycyloheptatrienone (C7)). The antioxidant 3- thujaplicin (hinokitiol) is an inhibitor of 5-, 12- and 15-LOXs. 

Cycloheptanes. Thujic acid p-bromophenacyl ester /3-thujaplicin 3,5,7-tri-bromohinokitiol " 3,7-dibromohinokitiol 5,7-dibromohinokitiol y-thujaplicin and the di-isopropylditropolonofuran utahin. " " ... 

Two new thujaplicin syntheses have appeared. The first (Scheme 20) depends on the presence of trimethylchlorosilane in the acyloin ring-closure in order to avoid Dieckmann condensation to the five-membered ring, and gives pure products. The scheme shows the )5-thujaplicin synthesis, but choice of the appropriate isopropylcyclohexanone leads to a- or y-thujaplicins. A mixture of j - (245)... 

It was argued [1256] that provided the tropolones did not act simply as metal ion scavangers (as in the case, for example, with ethylene diamine tetra-cetic acid [1258]), since chelation with metal ions undoubtedly underlies the antifungal properties [1259, 1260] of the thujaplicins and their congeners, then they should be able to compete with the catecholamines for the active enzymic site. The results showed that some of the tropolones, including the two thujaplicins, did in fact act in this way. Presumably the inhibition [1261] of dopamine jS-hydroxylase by y-thujaplicin occurs by a similar mechanism. 

Erdtman H, Gripenberg J 1948 Antibiotic substances from the heart wood of Thuja plicata, II. The constitution of y-Thujaplicin. Acta Chem Scand 2 625... 

Oxabicyclo[3.2.1]oct-6-en-3-ones (75) are also readily transformed to tropones (97) or y-tropolones (98) in a few steps. The tricyclic adduct (75 R = (CH2)9) can be readily converted to troponophane (101). Successful use of tetrabromoacetone and tribromo derivatives of methyl alkyl ketones in these reactions opens a new route to various naturally occurring troponoid compounds, viz. nezukone (102), a-thujaplicin (103) and hinokitiol 0-thujaplicin) (104), = respectively (Scheme 24). 

Tropolone derivatives are sometimes named as a, Bor y-derivatives (of. the thujaplicins above) or more generally are nunfcered as follows ... 

Pinaceae family Pinus spp. Picea spp. Thuja plicata Pseudotsuga Pine Spruce Western red cedar Douglas fir, Oregon pine y-Pinene, A-3-carene, thunbergol B-Thujaplicin 20% Sawdust in pet. 20% Sawdust in pet. 20% Sawdust in pet. 20% Sawdust in pet. Soft woods, allergy more commonly seen in carpenters or joiners... 

Furuya, T., Y. Asada, Y. Matsuura, S. Mizobata, and H. Hamada, 1997. Biotransformation of b-thujaplicin by cultured cells of Eucalyptus perriniana. Phytochemistry, 46 1355—1358. 

Inada S, Tsutsumi Y, Sakai K (1993) Elicitor of the P-thujaplicin accumulation in callus cultures of Cupressus lusitanica. J Fac Agr Kyushu Uni 38 119-126... 

Sakai K, Kusaba K, Tsutsumi Y, Shirashi T (1994) Secondary metobolites in cell culture of woody plants. III. Formation of P-thujaplicin in Cupressus lusitanica callus cultures treated with fungal elicitors. Mokuzai Gakkaishi 40 1-5... 

Nakagawa, Y. Cytotoxic effects of P-thujaplicin on rat thymocytes and prevention by the compound in tributyltin-induced thymocyte damage. Bull. 

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