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Publisher Summary The plant, Daphniphyllum macropodum ( D. macropodum ) Miquel is a lofty tree growing widely in Japan. It is interesting from the viewpoint of plant physiology that this plant puts forth new leaves in early summer before defoliation of the old leaves, which gradually fall. Thus, the plant D . macropodum is called Yuzuriha in Japanese because of such a phenomenon. The decoction of the bark and leaves of this plant had been used for a long time as a remedy for vermicide and asthma. Pharmacological properties of the Daphniphyllum alkaloids are briefly described in this chapter. From a viewpoint of plant classification, D. macropodum has been included in Euphorbiaceae, whereas Hutchinson and Hegnauer have suggested the new Daphniphyllaceae for this plant. Chemical constituents of the Daphniphyllaceae have been investigated and several new alkaloids have been isolated from D. calycium Benth. However, structural studies have not been made although it is quite desirable from chemotaxonomical aspects to elucidate their structures.

Deoxysilydianin methyl ether has been readily synthesized by means of anodic oxidation of the corresponding phenol as a key step, indicating a general method for synthesis of 9-oxaisotwist-8-en-2-ones in high yields.

Anodic oxidation of 4-allyl-2-methoxyphenol was carried out under various conditions, using an undivided cell, to afford two dienones (3 and 4) and two dimeric compounds (5 and 6). The dienone (4) was readily converted into demethoxyasatone (6), which was further subjected to photochemical reaction giving demethoxyisoasatone (7) in a good yield.

Reaction of several alkenes with the unstable cations electrogenerated from 3,4-dimethoxy-6-methylphenol as well as from p-methoxyphenol have been carried out, resulting in C–C bond formation to give the corresponding 1 : 1 adducts.

Some esters with two C6–C3 units have been oxidized with thallium (III) trifluoroacetate to afford the corresponding lactones of medium-sized rings, one of which is an 11-membered ring lactone, an 8,8′-secosteganacin-type compound.

In connection with the daphniphyllum alkaloids, some 6-oxa- and 2,8-dioxabicyclo[3.2.1]octanes, which are included as a partial structure of daphmacrine and codaphniphylline, have been synthesized starting from geraniol.

From a biogenetic point of view, the acid-catalyzed cyclizations of germacrones (1, 2, and 3) were carried out, using several kinds of reagents and solvents (80% aq AcOH, 80% aq HCOOH, AlCl3 in absolute ether, AcOH in PhSH, 100% HCOOH in PhSH, and concd H2SO4 in PhSH). In all cases, the stereospecific cyclizations of these germacrones took place to give cadinane-type, selinane-type or guaiane-type compounds depending on the kinds of reagents and solvents. The formation process of each compound will be presented in detail.

Reaction of N-benzoyl oxetanocin diacetate with trimethylsilyl pyrimidine in the presence of SnCl 4 gives both erythrofuranosyl pyrimidine and purine nucleosides.

Oxetanocin has been synthesized starting from cis-2-buten-1,4-diol through α- or β-D-oxetanosyl acetate as an important intermediate which has an α-(methyl oxalyloxy)methyl group at C 2 -position.

+ R 1C ′H e"??? x W3"? "f? T" 055°C - 0 d?′ 0 0 Base-catalyzed Equilibrium of Shyobunone and Related Compounds.

Triacetic lactone, 4-hydroxycoumarins and 2-chloromethyl-5-hydroxy-4-pyrone were subjected to anodic oxidation in methanol containing LiClO4 or NaCN to afford the corresponding methoxy or cyano compounds. In basic media, however, bispyrone and biscoumarol were produced from triacetic lactone (4-hydroxy-6-methyl-2-pyrone) and 4-hydroxycoumarin, respectively. The formation processes of these oxidation products are discussed.

Publisher Summary This chapter describes all of the newly isolated alkaloids from D.gracile and D.humile including their spectral and chemical properties. From a structural point of view, the 38 alkaloids so far obtained from the Daphniphyllaceae are classified into six types of nitrogen heterocyclic skeleton represented by daphniphylline, secodaphniphylline, daphnilactone-A, daphnilactone-B, yuzurimine, and daphnigracine. Daphilactone-B is a major component of several alkaloids isolated from the fruits of three kinds of plants growing in Japan. Decoctions of the bark and leaves of Daphniphyllum macropodum are used as a remedy for vermicide and asthma. The clinical findings show that decrease in body temperature just before the death, decreases in pH of urine, and change to positive in protein, bilirubin, and occult blood tests are observed in rabbit after oral administration of powdered plant extracts. Pathologic findings reveal cloudiness of the centrolobule and fragility of the liver. Boiled flesh-like findings with rough-surface of myocardium and filling of incoagulable blood in ventricle are recorded.

Two new lignans, kadsurin and kadsurarin, were isolated from Kadsura japonica Dunal, and their structures were established. The stereostructures of the schizandrin-type lignans including their conformations were elucidated by measurements of intramolecular nuclear Overhauser effects.

Isolation and structures of two novel neolignans, asatone (1) and isoasatone (2), are described. The structure of the latter, established by means of an X-ray crystallographic analysis of its dihydroxy derivative, is in full agreement with its chemical and spectral data. From a biogenetic point of view, furthermore, thermal and photochemical reactions of these neolignans and their derivatives were carried out. In particular,asatone was photochemically converted into isoasatone.

Reactions of 4-methoxy-2-oxopyran-6-ylacetic acid with acid anhydrides are presented. In particular the reaction with acetic anhydride gave tetra-acetic acid lactone methyl ether (6-acetyl-4-methoxy-2-pyrone), which was readily converted into tetra-acetic acid lactone (6-acetyl-4-hydroxy-2-pyrone)(I; R1= H, R2= Me).

Isolation and structures of two alkaloids, daphniphylline and codaphniphylline, are presented. The structure of the former, established by X-ray analysis, is in full agreement with its chemical and spectral data. The structure of the latter was deduced by comparison of the NMR, IR and mass spectra of both compounds. Finally, chemical transformation of daphniphylline to codaphniphylline was carried out.

Das Hydroxypyron (III) reagiert mit Crotonylchlorid (II) in Pyridin nach mehrstundigem Erhitzen zum Pyranopyran-dion (I); mit dem Saurechlorid (IV) entstehen unter gleichen Bedingungen die isomeren Dione (V) und (VI).

Intimate correlation between bioactivity and binding activity was shown using biologically active and inactive fluorescence-labeled probe compounds for nyctinasty. This results suggested the existence of a receptor which recognizes the aglycon of a leaf-opening substance on the motor cell.

Citreothiolactone has been isolated from the mycelium of Penicillium citreo-viride B. and its structure also been elucidated on the basis of its spectral data coupled with some chemical evidence. Biogeneric relationship between citreothiolactone and citreopyrone is also presented.

Both aerothionin and homoaerothionin, the novel metabolites of the sponges Aplysina aerophoba , A . fistularis and Verongia thiona , have been synthesized in racemic form.

A zwitterionic alkaloid, the hydration product of daphnilactone-B, has been isolated from the fruits of the plant Daphniphyllum teijsmanni Zollinger, and its structure also been determined on the basis of its spectral and chemical properties.

(±)-Silphinene has been synthesized from 2,6,6-trimethyl-9-methoxytricyclo[5.3.1.01,5]undec-9-en-8,11-dione which has been produced efficiently by means of electrochemical method.

Reaction of N-benzoyl oxetanocin diacetate with trimethylsilyl pyrimidine in the presence of SnCl 4 gives both erythrofuranosyl pyrimidine and purine nucleosides.

Two novel neolignans, heterotropanone and isoheterotropanone, have been synthesized by retro-Diels–Alder reaction of asatone in l-allyl-3,4,5-trimethoxybenzene. These two neolignans have also been obtained on thermal reaction of asatone followed by methylation.

C19-Obtusilactone dimer, a cytotoxic substance, has been isolated from Lindera obtusiloba Blume, and its structure also been elucidated on the basis of its spectral data coupled with chemical evidence.

13C NMR spectroscopy using INADEQUATE pulse sequence method has been used to deduce the labelling patterns of the three metabolites of Penicillium citreo-viride B. derived from [1,2-13C]acetate, indicating that their carbon skeletons consist of two different units [CH3COCH2COCH2COS-Enzyme and CH3COCH2COS-Enzyme].

(±)-Helminthosporal has been synthesized starting from a bicyclo[3.2.1]oct-1-en-2,8-dione which is produced on electrolysis of 3,4-dimethoxy-6-methylphenol in the presence of an excess of (E)-isoeugenol methyl ether.