Summary The allylphenols eugenol and methyleugenol are synthesized in 0. basilicum from ferulic acid and coniferyl alcohol whose sidechains are converted into allyl groups with retention of all carbon atoms, and hydrogen atoms of the hydroxy-group are quantitatively incorporated into the allyl group; a previous hypothesis for the biosynthesis of these compounds, which involved loss of the C-1 from these precursors, has therefore to be rejected.ON the basis of comparative phytochemical considerations it can be assumed that allyl-and propenyl-phenols in higher plants originate from the cinnamate carbon skeleton.' s2 The most likely intermediates are substituted cinnamyl aldehydes and cinnamyl alcohols. However, recent studies on the biosynthesis of eugenol in Ocimum basilicum led Canonica et al.3 to reject this possibility. They fed D,Lphenylalanine, labelled with l4C in different positions of the side chain mixed with non-specifically tritiated L-phenylalanine and observed in the case of [1-Wlphenylalanine an increase in the 3H : 14C ratio of the isolated eugenol. This was interpreted as being due to loss of the carboxyl group of phenylalanine at the cinnamate stage. Feeding experiments with L-we-Wlmethionine showed an incorporation of the labelled atom into the allylphenols and it was3~4 proposed that the terminal carbon atom may be derived from this precursor. Biosynthetically prepared U-tritiated ferulic acid was also found to be incorporated into the allylphenols. The above observations, that eugenol is derived from L-phenylalanine via oxygenated cinnamic acids with loss of the carboxy-group and incorporation of an 'extra' carbon atom into the side-chain, have been recently confirmed.' It is clear, however, that further work is required to clarify this situation.s f Ar-cH2 -w=cH2

In order to investigate the extent of the relationship between the three copper-containing glycoproteins, laccases I, I1 and I11 ( M I 70000,80000 and 390000 respectively) of Podospora anserina, the following experiments were carried out on laccases I1 and 111: (a) determination of amino acid composition ; (b) determination of N-terminal and C-terminal amino acid ; (c) determination of sugar composition; (d) dissociation studies on native and denatured laccases and also after removal of copper from the enzymes; (e) digestion of the carbohydrate moieties with the aid of glycosylhydrolases.A comparison between the results of these experiments and data previously obtained with laccase I allows the following conclusions to be drawn.

SummaryLignans constitute a class of naturally occuring phenolic compounds, widely distributed in higher plants. They are formally composed of two phenylpropanoid units, stercospecifically joined at the /f-carbon atoms of their side chains. Their biosynthesis has as yet not been investigated. To sec, if these plant phenolics originate from simple phenylpropancs, various radioactively labelled, putative precursors were fed to Forsythia shoots. Chemically synthezised arylpropane derivatives, such as Ή/ 1 'C-glucoferulic acid, -glucoferulic aldehyde, and -coniferin were incorporated into the lignans arctiin (3) and phillyrin (5) while 3 H-3,4-dimcthoxycinnamic acid was not incorporated. From these results it may be concluded that the hydroxylated compounds are direct precursors of these dimeric phenylpropanes and are incorporated through a dimerisation step without degrada tion of the Q-Q skeleton.

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Abstract-Using horse liver alcohol dehydrogenase, stereospecifically tritiated (R)-and (S)-(y-3H)-coniferyl alcohol was synthesized.Using both of these substrates it was demonstrated that cinnamyl alcohol dehydrogenase from lignifying Forsythia tissue specifically removes the pro-R-hydrogen atom of coniferyl alcohol in the oxidation to the aldehyde. This also means that in the reverse reaction the A-hydrogen of NADPH is transferred to the Re-site of coniferyl aldehyde.