Two new C_(19)-diterpenoid alkaloids from roots Aconitum hemsleyanium var. atropurpureum

A new franchetine-type C19-diterpenoid alkaloid 3-hydroxyfranchetine 1 and a new aconitine-type C19-diterpenoid alkaloid atropurpursine 2 have been isolated from the roots of Aconitum hemsleyanium var. atropurpureum. The structures of these new alkaloids were established on the basis of spectral data.

Two novel aconane-type diterpenes derived from C-nor-C_(19)-diterpenoid alkaloid

Two novel C-nor-B-homo aconane-type diterpenes 4 and 5, featuring a unique eight-membered ring system, were obtained by the treatment of C-nor-C19-diterpenoid alkaloid 3 with HNO2 in 8% and 21% yields, respectively. Structures of these two compounds were established based on the combination of spectroscopic data, including HRESIMS, 1D and 2D NMR data. A olausible mechanism for the formation of 4 and 5 is also presented.

Two New C_(19)-Diterpenoid Alkaloids from Delphinium davidii Franch

Two new C19-diterpenoid alkaloids, davidisines A （1） and B （2） along with thirteen known alkaloids were isolated from the whole herb of Delphinium davidii Franch. Their structures were established by spectral methods, especially 2D NMR techniques.

Three new C_(19)-diterpenoid alkaloids from Delphinium laxicymosum var. pilostachyum

Three new lycoctonine-type C19-diterpenoid alkaloids, laxicymine 1, laxicymisine 2, and laxicyminine 3 have been isolated from the whole herb of Delphinium laxicymosum var. pilostachyum W.T. Wang. Their structures were established by spectra data.

Two New C19-Diterpenoid Alkaloids with Anti-inflammatory Activity from Aconitum iochanicum

Two new C ig-diterpenoid alkaloids, 7,8-epoxy-franchetine （1） and N（19）-en-austroconitine A （2）, were isolated from Aconitum iochanicum. Compound 1 was a new C19-diterpenoid alkaloid with a 7,8-epoxy unit. Their structures were elucidated by comprehensive spectroscopic analyses including UV, IR, MS, 1D and 2D NMR. Biological ac- tivity tests indicated that two new compounds exhibited inhibitory activity against nitric oxide （NO） production in LPS-activated RAW264.7 macrophages. Compared with positive control, the two new compounds showed weak an- ti-inflammatory effects with the inhibition rate of 27.3% and 29.2%, respectively.

C_(19)-Diterpenoid alkaloid arabinosides from an aqueous extract of the lateral root of Aconitum carmichaelii and their analgesic activities

Eight new C_(19)-diterpenoid alkaloid arabinosides, named aconicarmichosides E–L(1–8), were isolated from an aqueous extract of the lateral roots of Aconitum carmichaelii(Fu Zi). Their structures were determined by spectroscopic and chemical methods including 2D NMR experiments and acid hydrolysis. Compounds 1–8, together with the previously reported four neoline 14-O-arabinosides from the same plant, represent the only examples of glycosidic diterpenoid alkaloids so far. At a dose of 1.0 mg/kg(i.p.), as compared with the black control, compounds 1, 2, and 4–6 exhibited analgesic effects with 465.6% inhibitions against acetic acid-induced writhing of mice. Structure–activity relationship was also discussed.

Synthesis of [6-6-6] ABE tricyclic ring analogues of methyllycaconitine

A new synthesis of the bridged [6-6-6] ABE tricyclic ring analogues of methyllycaconitine with the C-1 oxygenated substituents has been developed using an efficient aza-annulation of β-enamino ketone followed by a facile decarboxylation to form BE rings.Subsequent elaboration to form the A ring was achieved by a transannular acyl radical cyclization with concomitant equipment of the key C-1 oxygen functionality.