Hernandia ovigera

The following secodimeric alkaloids have been isolated from natural sources (+)-hernandaline (197), from Hernandia ovigera L. (158), (—)-natalinine (198) (759), and (+)-coyhaiquine (199) (160), the two latter from Berberis empetrifolia Lam. with the yields 0.00005 and 0.00008%, respectively. Appropriate aporphine-benzylisoquinoline or proaporphine-benzylisoqui-noline dimers are probably precursors of these seco alkaloids, although... 

The family Hernandiaceae consists of four genera Hernandia, Illigera, Gyrocarpus, and Sparattanthelium, and about 60 species of trees, shrubs, and woody climbers widespread in tropical regions. An example of Hernandiaceae is Hernandia ovigera L., which is grown as a tropical street tree. Hernandiaceae are member of the order Laurales and are known to abound with aporphines and lignans. 

Hernandia nyntphaeifolia (Hemandiaceae) pm 63,154 97 Hernandia ovigera (Hemandiaceae) apf 42, 317 84 Illigera luzonensis (Hemandiaceae) jnp 60,645 97 Illigera parviflora (Hemandiaceae) cty 22, 393 91 Lindera myrrha (Lauraceae) phy 35,1363 94 Neolitsea variabillima (Lauraceae) het 9, 903 78 Ocotea teleiandra (Lauraceae) rlq 23,18 92... 

Oxothalicarpine (255), mp 219-220°C (dec.), [a], 5 +115° (c 0.1, CHC13), although a known oxidation product of thalicarpine (94) (128), was first isolated as a natural product in 1976. Hernandia ovigera L. was the source of the biosynthetically related alkaloids oxothalicarpine, thalicarpine, dehydrothalicar-pine (255a), and hemandaline (256) (129,130). 

The noraporphine nandigerine, C18H17O4N, was isolated from Hernandia ovigera L. (Hernandiaceae). The base crystallized from methanol either as solvent free needles (mp 176°-177° [ajp - -248° in ethanol), or as plates of the methanol solvate, C]8Hi704N-CH30H (mp 99°-100°). The alkaloid hydrochloride salt melted at 245°-247° (decomp.) (33b). 

Ovigerine, obtained from Hernandia ovigera, crystallized only as the hydrochloride, CigHi504N-HCl (mp 300° decomp. [aj -P 177° in H2O). The UV-spectrum of this salt, 317, 270, 234 mp. (log e 3.77, 4.10, and 4.29), was suggestive of a 1,11-substituted aporphine. The NMR-spectrum of the free base showed no signals characteristic of either X-methyl or methoxyl, but complex signals characteristic of two superimposed methylenedioxy groups appeared centered at 4.12 and 3.99 t. 

Thalicarpine (LX), C41H48O8N2 (mp 160°-161°) was first isolated from Thalictrum dasycarpum Fisch. and Lall. (30). Later it was obtained from Thalictrum minus L. var. datum Jacq. (31) and from Hernandia ovigera (Auth. ) (32). 

Structure Elucidation and Synthesis of the Lignans from the Seeds of Hernandia ovigera L. 

The plants of Hernandiaceae comprise about sixty-five species in four generic kinds. The plants of Hernandia ovigera L. are widespread in the tropics and the subtropics. In Japan, these plants grow on the beaches of Okinawa and Ogasawara islands. In the Okinawa region, the plants have been used as therapeutic agents. A number of groups have been involved in the isolation and structure elucidation of aporphine-type and isoquinoline-type alkaloids from these plant materials as well... 

The seeds of Hernandia ovigera (8 kg), which were collected in Okinawa, were crushed into small species. Dried seeds (2 kg) were extracted with MeOH (31 x 3) under reflux. The combined extracts were evaporated under reduced pressure to give a residue (1.09 kg). This residue was treated with petroleum ether to remove soluble materials, which afforded the insoluble materials (518 g). This solid residue was extracted with benzene under reflux. After removal of the solvent under reduced pressure, an oily substance (242 g) was obtained. This oily material was recrystallized from EtOH to afford crude crystals of desoxypodophyllotoxin... 

Hata first isolated desoxypodophyllotoxin, which showed mp 167- -168t) and [a ]D -116° (c=2 in CHC1,), from the seeds of Hernandia ovigera, and he named it "hernandion". However this compound was identical with anthricin which was isolated from Anthricus sylvestris Hoffm. (ref. 6). Subsequently it was found to be identical with a product resulting from dehydroxylation of podophyllotoxin (11) by Hartwell and co-workers (ref. 7). Since this compound has been given several names, it is reasonable to call it "desoxypodophyllotoxin" on account of the structural relationship with podophyllotoxin according to Hartwell s proposal (ref. 8). 

Hernolactone (16) is a new bisbenzyl- y -butyrolactone-type lignan isolated from Hernandia ovigera. Although the syntheses of bisbenzyl- y -butyrolactones have been reported by many groups (ref. 2), its synthesis was carried out according to the known procedure (ref. 35) shown in Chart 6. 

In conclusion, two kinds of 1-hydroxyphenyltetralin-type lignans, epipodophyllotoxin (12) and podophyllotoxin (11), were obtained from desoxypodophy-llotoxin (3), which is available in large quantities from the seeds of Hernandia ovigera L.. 

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