New diterpenoid alkaloids

Peng, C. S., Chen, D. L., Chen Q. H. and Wang, F. P. 2005. New diterpenoid alkaloids from roots of Aconitum sinomontanum. Chinese Journal of Organic Chemistry, 25 1235-1239. 

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... 

Delectine.—A new diterpenoid alkaloid, delectine, has been isolated from Delphinium dictyocarpum7 This base, C31H44N2O8, m.p. 107—109 C, was shown to be the anthranilate ester (6) by chemical and spectral studies and by conversion into 00 -dimethyl-lycotonine (7). Acetylation of delectine gave an NO-diacetyl derivative (8). On alkaline hydrolysis of delectine, anthranilic acid and the alkamine (9) were obtained. Methylation of (9) with methyl iodide-sodium hydride gave (7), which was... 

Among them five alkaloids and three flavonoid glycosides are known only from this plant while the rests are also reported from other plants. Gao et al. (2004) isolated and characterized six alkaloids (Figure 3) they are navirine (compound 1), isoatisine (2), hordenine (3), atisine (4), hetisinone (5) and delfissinol (6). Among them navirine (1) was reported as a new diterpenoid alkaloid while other five alkaloids are known in other plants too. Cao et al. (2008) reported two new C-20 alkaloids naviculine A (7) and B (8). Other terpenoid alkaloids were reported by our research group (Dall Acqua et al. 2008) they are navirine B (9), navirine C (10) and chellespontine (11). This latter one was previously isolated from aerial part of Consolida hellespontica (Desai et al., 1993). 

Gao, L., Wei, X. and Yang, L. (2004). A New diterpenoid alkaloid from a Tibetan medicinal herb Aconitum naviculare Stapf. Journal of Chemical Research, 4 307-308. 

The Canadian workers, Jones and Benn, reported the isolation of two new diterpenoid alkaloids A and in very small amounts from >. bicolor Nutt (100,101). Structures 83 and 84 were assigned to alkaloids A and B, respectively, primarily on the basis of the correlation with the 13C NMR spectra of a variety of model Ci9-diterpenoid alkaloids, e.g.-, deoxyly-coctonine and isotalatizidine, and the results obtained from the pyrolysis study of alkaloid A. Alkaloid A (C25H39NO6), an amorphous base, formed a hydroiodide salt (mp>240°). The IR and H and 13CNMR spectra revealed the presence of a tertiary methyl, an N-ethyl, an acetoxyl, two... 

Alkaloids of Delphinium pentagynum,— Researchers in Spain have isolated a new diterpenoid alkaloid from plants of D. pentagynum Lam. collected in southern Spain. Gadesine [C23H35NO6 m. pt. 174—177 °C] was assigned structure (42) on the basis of the chemical, i.r., n.m.r., and mass spectral data, and... 

Alkaloids from Aconitum gigas Lev. et Van. Gigactonine and Atisine.—Sakai, Shinma, and Okamoto have isolated a new diterpenoid alkaloid, gigactonine,... 

Alkaloids of Delphinium dictyocarpum 14-Acetyldelectine, Delectinine, and Dictionine.— Three new diterpenoid alkaloids have been isolated from plants of... 

Applications of N.M.R. Spectrometry to the C19 Diterpenoid Alkaloids 14-Acetylbrowniine.—A review of recent applications of carbon-13 n.m.r. spectrometry to the solution of some of the complex problems of C19 diterpenoid alkaloid chemistry has appeared. Using proton-decoupling techniques and additivity relationships, the carbon-13 chemical shifts for eighteen aconitine and lycoctonine-type alkaloids were assigned. Applications of these methods for the identification and structure elucidation of several new diterpenoid alkaloids were discussed. The new data presented in this work included the identification of... 

Sham yanov ID, Tashkhodzhaev B, Mukhamatkhanova RE, Sultankhodzhaev MN, Levkovich MG, Abdullaev ND, et al. Sesquiterpene lactones and new diterpenoid alkaloids from Artemisia korshinskvi. Chem Nat Comp 2012 48(4) 616-21. 

Sultankhodzaev MN, Tashkhodzhaev B, Averkiev BB, Antipin MYu. Secokaraco-nitine, a new diterpenoid alkaloid from Aconitum karacolicum. Chem Nat Comp 2002 38(l) 78-82. 

Zhang ZT, Lin XY, Chen DL, Wang FP (2010) New diterpenoid alkaloids from Aconitum liangshanicum. Helv Chim Acta 93 811-817... 

Mericli AH, Cagal-Yurdusever N, Ozeelik H, Zapp J, Kiemer AK (2012) A new diterpenoid alkaloid from the roots of a white-flowering Aconitum orientale sample. Helv Chim Acta 95 314-319... 

Li C, Hiiasawa Y, Aiai H, Aisa HA, Morita H (2010) A new diterpenoid alkaloid, sharwuphinine A from Delphinium sharwurense. Heterocycles 80 607-612... 

Gonzalez AG, DelaFuente G, Diaz R 1982 Four new diterpenoid alkaloids from Delphinium pen-tagynum. Phytochemistry 21 1781-1782... 

Diterpenoid Alkaloids.—The structure and synthesis of the diterpenoid alkaloids have been reviewed. The subject is also covered in detail in the Specialist Periodical Report on the Alkaloids. A number of new alkaloids with the ent-kaurene skeleton have been isolated from Anopterus glandulosus and A. macleayanus. The structure of the major alkaloid anopterine (104) was assigned ... 

The chemistry of the diterpenoid alkaloids, rather than their structure elucidation by physical methods, has attracted more interest during the year covered by this Report. While several new alkaloids have been reported, most of the research on these polycyclic, polyfunctional bases has involved chemical conversions and synthetic methods. Most notably, Wiesner s group at New Brunswick, Canada, has reported a fourth-generation synthesis of the delphinine-type alkaloids. That this marvel of synthetic engineering accomplishes the stated goals1 of a highly efficient, fully regio- and stereo-specific synthesis of these complex natural products is abundantly clear. 

Recently, a new class of diterpenoid alkaloids, known as bisditerpenoid alkaloids, has been isolated from the seeds of Delphinium staphisagria (2). The bisditerpenoid alkaloids (e.g., staphisine, iv) may be formally derived by... 

In 1964 Molodozhnikov and co-workers (137) reported the isolation of several diterpenoid alkaloids from the shrub Spiraea japonica L. fil. of the Roseaceae family. Later Goto and co-workers (138) examined alkaloids of the same plant (Japanese name Shimotsuke ) and isolated 10 new alkaloids. The structures of 3 of these, spiradine A (152), spiradine B (153), and spiradine C (154) have been determined by chemical correlations coupled with a single-crystal X-ray analysis (139) of spiradine A methiodide (155). 

The 13C-NMR spectra of these compounds were analyzed to identify and distinguish skeletal features of the atisine and veatchine-type alkaloids for use in the structure elucidation of new C20-diterpenoid alkaloids. 

The structures of two new C20-diterpenoid alkaloids designated as ovatine (6) and lindheimerine (7), isolated from G. ovata var. lindheimeri, have been elucidated (33) with the help of13C-NMR spectroscopy. Similarly, the structure of dihydroajaconine (81) was also established (S3) with this technique. 

A new method for converting the N—CH2—CH2OH group in diterpenoid alkaloid derivatives into the isooxazolidine derivatives using active manganese dioxide has been reported by Pelletier, Mody,... 

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... 

Syntheses Directed Toward C20 Diterpenoid Alkaloid Systems.—A denudatine model (116) has been prepared by the New Brunswick group,49 based on their previous demonstration that maleic anhydride adds stereospecifically to the diene (117) to give (118)50 (cf. Vol. 5, p. 238). Alkylation of the model compound (119)... 

A new approach to the abe ring system of the pentacyclic C20 diterpenoid alkaloids has been reported by van der Baan and Bickelhaupt.51 For the model system of major interest, (134) was prepared from (133) by reaction with cyano-acetamide. Treatment of (134) with allyl bromide gave almost exclusively C-alkylation, to afford (135). On heating (135) at 100—110°C, a Cope-type rearrangement to (136) was effected. This compound was then N-alkylated with ethyl iodide-DMF, the product being (137). Treatment of (137) with IV-bromosucc-... 

In addition to several newly reported diterpenoid alkaloids, the structures of some forty alkaloids have been revised on the basis of recent work. The structures presented in this Report have been revised from those reported in the literature to reflect these recent corrections. The level of efforts directed toward the synthesis of diterpenoid alkaloids was substantially reduced this year, with only a description of the synthesis of napelline by Professor Wiesner s group appearing. No reports of new work on the Daphniphyllum diterpenoid alkaloids were available to our laboratories. 

Alkaloids of Aconitum yesoense Nakai.—Sakai and co-workers42 have reported the isolation and elucidation of the structure of three new C19 diterpenoid alkaloids from Aconitum yesoense Nakai. These minor bases, ezochasmanine, ezo-chasmaconitine, and anisoezochasmaconitine, were isolated together with pseudo-kobusine (92), chasmanine (59), and jesaconitine (93). Ezochasmanine (94) (C25H41N07 m.pt 115—118 °C) formed a mixture of the monoacetate (95) and the diacetate (96) when treated with acetic anhydride in pyridine. The reaction of... 

Berm, M. H. and Jacyno, J. (1983) The Toxicology and Pharmacology of Diterpenoid Alkaloids, Pelletier S. W. Alkaloids Chemical and Biological Perspectives, Vol. 1, Wiley, New York, 153-210. 

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. ... 

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