Delphinin

Delphinium Staphisagria L. From the seeds of this species, the oil of which is used as a pediculicide, Brandes isolated delphinine in 1819, and this and other alkaloidal components were subsequently examined by various workers including Marquis, Kara-Stojanov, Ahrens, Keller, Walz and most recently by Jacobs and Craig. ... 

Delphinine, C34H47O9N (Walz) or C33H45O9N (J. and C.). The alkaloid crystallises in rhombs, or six-sided plates, m.p. 198-200°, [a]f ° + 25° (EtOH), shows mutarotation in alcoholic solution, and forms an acid oxalate, B. H2C2O4, m.p. 168° dry), a hydrochloride, B. HCl, m.p. 208-210°, and a monobenzoyl derivative, m.p. 171-3°. On alkaline hydrolysis it yields one molecule each of acetic and benzoic acids. The basic, hydrolytic product of this action is delphonine, C24H3g07N, which is amorphous, but can be distilled at a bath temperature of 140° and a pressure of 0-001 to 0-0001 mm. The brittle, possibly semi-crystalline resin so obtained, has m.p, 76-8° and [a]f ° - - 37-5 (EtOH). 

On hydrogenation, delphinine forms hexahydrodelphinine, CgaHgjOgN, m.p. 192-3°, by reduction of the benzoyl radical, hexahydrobenzoic acid replacing benzoic acid as a product of hydrolysis. 

Delphinine contains one hydroxyl, one methylimino and four methoxyl groups, which with the acetoxy and benzoyloxy groups accounts for all the oxygen atoms of the alkaloid. 

This kind of reaction was first recorded for aconitine (p. 675) and it serves to emphasise the parallelism in reactivity, and probably therefore in structure, which exists between aconitine and delphinine and possibly between the whole range of aconite and larkspur alkaloids. 

Another example of this is the loss of acetic acid when delphinine is heated in hydrogen at 200-215°. Just as aconitine is so converted into pyraconitine so delphinine yields pyrodelphinine, C3 H4 0,N, m.p. 208-212°, and similarly a-oxodelphinine, C33H430j qN, under like treatment loses acetic acid and yields pyro-a-oxodelphinine, C3 H3gOgN, which crystallises from methyl alcohol in needles, m.p. 248-250°, after sintering at 238°. This, on hydrogenation, forms a hexahydro-derivative, m.p. 183-5°, presumably by saturation of the benzoyl radical, which therefore leaves unexplained the mechanism by which acetic acid is lost in this pyrolytic reaction (c/. pyropseudaconitine, p. 683). 

The action of hydrochloric and nitric acids on delphinine and certain of its derivatives has also been investigated (Jacobs and Craig,i° 1940). 

The following three alkaloids described by early workers on D. staphi-sagria are not well characterised Delphisine, m.p. 189° said to resemble and to be isomeric with delphinine. Delphinoidine, C25H43O4N, amorphous. Staphisaghoine,i C4oH4jOjN2, amorphous, m.p. 275-7°. 

Vascular bilberry. extract/delphinin, myrtillin (aglycon delphinidin) in preventing... 

Delphinin CfjHloO — glucose delphinidin + para-hydroxy-henroic acid... 

The constitution of a number of alkaloids has not as yet been definitely established. Among these are aconitine from aconite, delphinine from larkspur, jervine and protojervine from veratrum viride, cevadine from sabadilla seed, lobeline from lobelia, the curare alkaloids from Chondro-dendron tomentosum, sanguinarine from sanguinaria, and many others. 

Comparison of the I3C NMR spectrum of pyrodelphinine [552] and delphinine [553] shows the large high frequency shift of C(17) in [552] (S 78-6 in [552], d 63-3 in [553]) resulting from interaction between the nitrogen lone pair and the C(8)-C(15) double bond. (326) The 13C NMR spectra of a variety of other diterpenoid alkaloids (from aconitum... 

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. 

Staphisagnine (193) and staphisagrine (194) were also isolated (150) in extremely small amounts from the mother liquors accumulated during the isolation of delphinine from the seeds of D. staphisagria. These alkaloids are unusual in containing an oxazolidine ring of the atisine and veat-chine type in addition to many of the uncommon features of the staphisine skeleton. 

Alkaloids of Delphinium staphisagria Delphidine31 and Delphirine.32—These new bases were isolated from the mother liquors accumulated from the large-scale separation of delphinine (40) from the seeds of D. staphisagria L. 

A New Synthesis of Napelline.—Workers at New Brunswick have reported an excellent stereospecific synthesis of napelline (70), based on their fourth generation methods that were developed in the synthesis of several delphinine-type alkaloids.59 These methods had previously been explored with model compounds, and employ the rearrangement of a denudatine system to a napelline system.60 The starting material (123) for this synthesis was prepared by the route analogous to that used for the preparation of 13-deoxydeIphonine.60,61... 

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