Homalium

Geissosis prainosa] New Caledonia leaves Homalium spp New Caledonia 9 species leaves 3 species 3 species 3 species... 

Scheme 65 Internal rearrangement on P-lactams leading to homalium alkaloids containing spermine backbones...

Homalium pronyense Guillaum (Flacourtiaceae) (Samydaceae) (XII, 481 XIII, 409)... 

A (-)-homaline synthesis, which is adaptable for the synthesis of the natural unsymmetrical Homalium alkaloids, is given in Scheme VI/11 [40] [41]. The eight-membered diaza part, VI/52, was synthesized by a transamidation reaction. It was possible to prepare homaline (VI/50) and the three other minor bases, hopromine, hopromalinol, and hoprominol, by combination of different eight-membered ring building blocks. As shown in Scheme VI/11, homaline (VI/50) was synthesized in 36% yield. 

Homaline (194) is the main alkaloid of the leaves of Homalium pronyense (134-137). The bases hopromine (195), hoprominol (196), and hoproma-linol (197) have been found as minor alkaloids in the same plant (136). Homaline is composed of two cinnamic acid units and spermine. 

Homalium foetidum (Roxb.) Benth./Malas Intsia bijuga (Golebr.) O. Kuntze/Kwila Neonauclea maluensis S. Moore/Yellow hardwood... 

Finally, in an accompanying communication, Crombie et al. described an innovative diazocine ring expansion, in which intramolecular transami-dation was used to convert the Homalium alkaloid precursor 180 (R = R1 = H) into the alkaloid dihydroperiphylline (for details, see Section IV,D) (86TL5151). 

These glycosides have been isolated from the roots of Homalium zeylanicum Benth... 

Investigation of Allophylus cobbe, Homalium foetidium, and Aglaia species for alkaloid content has so far yielded only simple aromatic amide derivatives. An interesting phenethylamine-sesquiterpenoid alkaloid, elegantine, has been isolated from Saussurea salsa and S. elegansV NJV-Dimethylamino-p-hydroxy-phenethylamine is the first alkaloid to be extracted from marine algae. ... 

Homalium africana Benth. (Flacourtiaceae formerly Symadaceae)... 

Homalium iongifolium Glycoside (30) Shaari el at, (1995) Silica gel ElOAcMeOH(l 1) jGIbosc OH... 

Shaari, K. and Waterman, P. G. (1995) Further glucosides and simple isocoumarins from Homalium longifoHum. Nat. Prod. Lett 7,243-250. 

Finally in this section, a novel ring expansion reaction of 3-lactams has been described by Crombie et al. for the synthesis of members of the Homalium family of alkaloids such as hopromalinol (152) (Scheme 2).43... 

Details concerning the structural elucidation of homaline (57) and the related alkaloids hopromine, hoprominol, and hopromalinol, isolated from Homalium pornyense, have been published. The related spermidine alkaloid periphyllene (58) has been recently isolated from the leaves of Peripterygia marginata. Its structure and absolute stereochemistry were determined by spectral and chemical-degradation studies. 

Ishikawa, T. Nishigaya, K. Uchikoshi, H. Chen, I-S. Cochinolide, a New y-Alkylidene Bicyclic Butenolide with Antiviral Activity and Its P-Glucopyranoside from Homalium cochinchinensis. J. Nat. Prod. 1998, 61, 534-537. 

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