Alkaloids from Aconitum Species

Five new diterpenoid alkaloids have been isolated from Aconitum species (Ranunculaceae) and five from Delphinium species (Ranunculaceae). Four new Anopterus (Escalloniaceae) bases have been identified. The most significant synthetic achievement has been the total synthesis of racemic chasmanine. A detailed review of the alkaloids of Delphinium staphisagria has appeared.1... 

Research on diterpenoid alkaloids published during the past year has continued to expand the body of structural and synthetic information available on these complex plant bases. The structures of ten new alkaloids from Aconitum and Delphinium species, including seven new bisditerpenoid alkaloids, have been reported. Tlie most significant progress in methods of structure elucidation has been the very successful applications of n.m.r. to the study of complex diterpenoid alkaloids. The New Bruns wick group under Professor Karel Wiesner has continued its progress toward the syntheses of the Ci9-aconitine-type alkaloids. An historical account of the synthesis of talatisamine (1), the first synthesis of a hexacyclic aconite alkaloid, has been published. This work was reviewed in a previous Report. ... 

DITERPENE ALKALOIDS FROM ACONITUM, DELPHINIUM, AND GARRYA SPECIES THE C -DITERPENE ALKALOIDS... 

Sawada and coworkers 2 have reported preliminary studies on the induction of callus tissues from Aconitum ibukiense var. eizaenense Nakai. The production of alkaloids by these callus tissues was indicated by a positive Dragendorff test of the weak base fraction of an extract. These studies are significant in that such methods might be useful for the production of alkaloids from rare species of plants. 

Yeratroylpseudacoiiine and Diacetylpseudaconitine.—Purushothaman and Chan-drasekharan examined the roots of Aconitum ferox for basic components. Czechoslovakian workers had earlier reported the isolation of seven alkaloids from this species. They identified pseudaconitine (29), bikhaconitine (30), chas-maconitine (31), and indaconitine (32). 

Alkaloids of Aconitum gigas Lev. et Van.—A full report on the structure elucidation of the alkaloids from this species has appeared (c/. Vol. 9, p. 221). 

In Turkey there are about 31 Delphinium, 8 Consolida and only 4 Aconitum species. So far we had studied 17 Delphinium, 7 Consolida and 3 Aconitum species. From these studies we have obtained more than 100 alkaloids, about 50 of them were new compounds [17]. 

Recently we have studied the fourth Turkish Aconitum species namely A. cochleare Woroschin. The aerial parts and the roots were investigated separately. From the aerial parts four alkaloids talatisamine, 14-acetyltalatisamine, cochleareine (9) and acoleareine (10) were isolated [18]. 

Perhaps the most important examples of terpenoid alkaloids from a pharmacological point of view are those found in aconite or wolfsbane (Aconitum species Ranunculaceae) and species of Delphinium (Ranunculaceae). Whilst Aconitum... 

The diterpenoid alkaloids, isolated mainly from Aconitum and Delphinium species (Ranunculaceae), have been of great interest since the early 1800s because of their pharmacological properties. Extracts of Aconitum species were used in ancient times for treatment of gout, hypertension, neuralgia, rheumatism, and even toothache. Extracts have also been used as arrow poisons. Some Delphinium species are extremely toxic and constitute a serious threat to livestock in the western United States and Canada. Delphinium extracts also manifest insecticidal properties. In the last 30 to 40 years, interest in the diterpenoid alkaloids has increased because of the complex structures and interesting chemistry involved. 

Isohypognavine has been isolated (99, 106) from the roots of A. majijai Nakai and A. japonicum Thumb. Its name is unfortunate since it is not an isomer of hypognavine. This alkaloid has not been isolated from any other Aconitum species. On alkaline hydrolysis, isohypognavine gave an alkamine known as isohypognavinol. On the basis of chemical correlation (107) of isohypognavine with kobusine, the partial structures 108 and 109 were... 

Even though much is already known about the toxicity of diterpene alkaloids that contribute to the toxicity of Consolida, Delphinium, and Aconitium species, no antiviral study has been so far reported on this type of alkaloids. Therefore, no SAR studies have been encountered by us on the antiviral or antimicrobial activities of these alkaloids. However, a quantitative SAR analysis performed on a number of diterpene alkaloids isolated from an Aconitum sp. indicated that biological activity of these alkaloids may be related to their toxicity rather than to a specific pharmacological action [40]. In a current study on 43 norditerpenoid alkaloids from Consolida, Delphinium, and Aconitum species against several tumor cell lines, lycoctonine and browniine were... 

Alkaloids of Aconitum falconeri Falaconitine and Mithaconitine. In addition to the previously known veratroylpseudaconine (5), pseudaconitine (6) and indaconi-tine (7), two new C19 diterpenoid alkaloids, falaconitine and mithaconitine, have been isolated from the roots of Aconitum falconeri Stapf.13,14 Singh and coworkers15 had reported a preliminary study of the two alkaloids, bishatisine and bishaconitine , isolated from this species. However, in the recent work,13,14 no bishatisine or any atisine-type alkaloid was identified, and the data reported for bishaconitine were consistent with a mixture of falaconitine and several closely related bases. The identities of (5), (6), and (7) were determined primarily by H and 13C n.m.r. techniques and confirmed by comparison with authentic samples.14... 

Alkaloids of Aconitum nasutam.-Plekhanova and Murav eva have reported studies of the alkaloids from A. nasutum.20 From the aerial parts of this species, they obtained 0.42% total alkaloids. The roots yielded 1.6% alkaloid fraction, which was shown to contain at least five components. One of these was isolated as a base, C22H35N04, m.pt. 148 °C, [a °= -20.7°. 

Alkaloids of Aconitum delphinifolium DC.—Benn and co-workers22 have isolated a new alkaloid, delphinifoline (C23H37N07 m.pt 218—220 °C), from this species. Structure (58) was assigned on the basis of the H and 13C n.m.r., i.r., and mass-spectral data and confirmed by an X-ray crystallographic structure... 

Alkaloids of Aconitum heterophylloides Stapf.—Atisine (65) and a new amorphous alkaloid, heterophylloidine, C23H29N04, have been isolated from the roots of this rare species from the Himalayan region of India.27 When a methanolic solution of... 

Diterpene (C20) and norditerpene (C19) alkaloids are typically found in species of the Aconitum, Delphinium, and Consolida genera [43-46]. The toxic effects of the Delphinium and Aconitum species can be attributed to their norditerpene alkaloid content. Thus, many of the examples presented in this chapter have been taken from the analysis of norditerpene alkaloids however, similar experiments would be applicable for any of the diterpene alkaloids (Figure 13.19). 

APCI-MS has been used extensively for the structural analysis of diterpene alkaloids from various Aconitum species for both positional and stereoiosomeric determination [ 57,58]. By controlling the drift voltage between the first and second electrodes in... 

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