[Recent progress on the lupine alkaloids in leguminous plants growing mainly in Japan]

The existence of the lupine alkaloids in leguminous plants mainly growing in Japan has been thoroughly ascertained, and 106 kinds of lupine alkaloids, including 51 kinds of novel lupine-type alkaloids, have been isolated and characterized from 28 species belonging to the 9 genera of leguminous plants (Table 1). Among them (e.g. Fig. 1-2), a number of unusual types of alkaloids (e.g. Fig. 2) may be regarded as possible metabolites of the lupine alkaloids that coexist in the same plant, such as (+)-kuraramine-type, (-)-mamanine-type (Fig. 3), (-)-tsukushinamine-type (Fig. 5) and (+)-hupeol-type (Fig. 7) alkaloids, or as products of alternative biosynthetic pathway, such as tashiromine-type and (-)-camoensidine-type alkaloids in the Maackia species. The biosynthetic pathways (Fig. 8) by enzymes (Fig. 9) and some of biological activities (e.g. Table 2) of the lupine alkaloids have also been presented. The leguminous plants that accumulate the common lupine alkaloids may be divided into three main groups: plants which produce the matrine, the cytisine/sparteine, and the lupinine-type alkaloids. In addition, the Maackia species and a few other species produce rare bases. Some of more detailed chemical properties of the lupine alkaloids that have been isolated and studied in our laboratory, including a newly proposed biosynthetic pathway, biotechnological studies, a summary of biological activities, and a discussion of chemotaxonomic aspects of the leguminous plants which accumulate lupine alkaloids, have been reviewed by authors in English papers shown in References 1, 55, 65, and also reviewed by one of the authors (I.M.) in a Japanese papers shown in Ref. 66, in which many aspects of the active research history on (+)-matrine and its relatively alkaloids since 1892 in Japan are described.