Nicandra physaloids

The mechanism of acetoacetate coupling in the biosynthesis of hygrine (209) has been studied by feeding sodium [3-14C]- and [4-14C] acetoacetate to Nicandra physaloides 134). 

New sources of hygrine are the roots of Nicandra physaloides (L.) Gaertn. (Solanaceae) (9, JO), Dendrobium chrysanthum Wall. (Orchidaceae) (11), and Cochlearia arctica Slecht (Cruciferae) (12). Hygroline was also isolated from this latter source as well as from Carallia brachiata (Lour.) Merr. (Rhi-zophoraceae), a plant from eastern Asia, New Guinea, and Queensland (13), and... 

The 9(10-> l9)-abeo analogue (6) of oestrone methyl ether has been shown by X-ray crystallography to have the normal 9a -configuration, but because of the chair conformation of the enlarged ring b the molecule differs considerably in shape from oestrone methyl ether. X-Ray, n.m.r., and o.r.d. data establish the structures and absolute configurations of a series of insect-repellent steroids isolated from Nicandra physaloides. The structure and conformation of the 6-sila-steroid (7) have been determined. ... 

Insecticidal properties of withanolides were first noticed on components isolated from the Peruvian plant Nicandra physaloides. Nicandrenone (Nic-1) (90), the major component isolated from this plant, was known by its bitter taste and its insecticidal properties. [58-61]... 

Nicotiana tahacum L. (5, 13) Papaver somniferum L. (3, 5) Nicandra physaloides Gaertn. (6) Physalis alkekengi L. (6) Hordeum vulgare L. (35, 48, 49) Hordeum murinum L. (35) Panicum miliaceum L. (35) Strychnos potatorum L. (44) Strychnos spinosa Lam. (44)... 

Tropane Alkaloids.—[3- C]Acetoacetate has been shown to be a precursor for hygrine (38) (in Nicandra physaloides), the activity being localized at C-2. Unfortunately, because of the labelling site in the precursor, it is uncertain whether the acetoacetate was incorporated intact or only after prior degradation to acetate (no comparative levels of incorporation of acetoacetate and acetate were obtained either). 

Ornithine is incorporated into pyrrolidine rings unsym-metrically in several Datura species, but a symmetrical intermediate is involved in Nicotiana species, Erythroxylum coca, Duboisia leichardtii, Hyoscyamus albus, and Nicandra physaloides (Leete, 1990). 

Begley MJ, Crombie L, Ham PJ, Whiting DA (1972) Constitution of four novel methyl steroid relatives (ring D-anunatic) from the insect repellent plant Nicandra physaloides X-ray analysis of Nic-10. J Chem Soc Chem Commun 22 1250-1251... 

Leete E (1983) Biosynthesis and metabolism of the tobacco alkaloids. In Pelletier SW (ed) Alkaloids - chemical and biological perspectives, vol 1. Wiley, New York, pp 85-152 Leete E (1985) Biosynthesis of hygrine from [5- C]omithine via a symmetrical intermediate in Nicandra physaloides. Phytochemistry 24 953-955 Leete E (1990) Recent developments in the biosynthesis of the tropane alkaloids. Planta Med 56 339-352... 

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