Flavonoidal alkaloids

Some of the potential uses of the fats and oils found in plants have been reviewed and some uses of carbohydrate-based polymers briefly discussed. Plants contain a whole variety of other chemicals including amino acids, terpenes, flavonoids, alkaloids, etc. When the potential for these naturally occurring materials are combined with the secondary products that can be obtained by fermentation or other microbial processes or by traditional chemical transformations, the array of chemicals that can readily be created from renewable resources is huge. In this section a few of the more interesting examples are considered. 

The first flavonoidal alkaloids to be isolated were ficine (4) and isoficine (5) in 1965 from Ficus pantoniana King. (Moraceae) (i). These alkaloids have not... 

Most recently a series of piperidinyl-flavonoid alkaloids have been isolated from two Buchenavia spp. (Combretaceae) (6). The leaves of B. macrophylla Eichl. yielded buchenavianine (8) and iV-demethylbuchenavianine (9). The fruits... 

The flavonoidal alkaloids have thus been found widely scattered throughout the higher plants. In view of the ubiquitous occurrence of flavonoids and the simplicity of the nitrogenous component in the compounds so far isolated, it is quite possible that they may occur in more species. The occurrence of the flavonoid alkaloids in Buchenavia but not Terminalia has been used to confirm the taxonomic distinction between these genera (6). 

The UV spectra of all flavonoidal alkaloids is related entirely to the flavonoid part of the molecule. Table I lists the data reported for each alkaloid. Flavones exhibit maxima in the region of 270-325 nm whereas the flavanones show maxima at about 250-320 nm. The flavan vochysine shows an absorbtion only at 275 nm since there is no conjugation system in ring C. 

No studies have been carried out on the biosynthesis of the flavonoidal alkaloids. It is assumed, however, that the flavonoid moiety is formed by the usual... 

Bennett, R.N. et al., Profiling glucosinolates, flavonoids, alkaloids, and other secondary metabolites in tissues of Azima tetracantha L. (Salvadoraceae), J. Agric. Food Chem., 52, 5856, 2004. 

Auzi, A.A., Hartley, T.G., and Waterman, P.G., Distribution of flavonoids, alkaloids, acetophenones and phloroglucinols in the genus Bosistoa (Rutaceae), Biochem. Syst. EcoL, 25, 611, 1997. 

This sea grass49 contains the flavones hispidulin and luteolin as well as the flavonoidal alkaloid phyllospadine (45). 

Flavonoid alkaloids Buchenavia capitata CHCl3-MeOH-0.5% HCl (5 5 3) SanM CPC... 

Main components 1-3% essential oil, sesquiterpene lactones [131, 132], flavonoids, alkaloids [133]. 

This section summarises recent work on alkaloids containing the pyrrolidine nucleus. A short review concerning the synthesis of this group has appeared. A variety of Labiatae plants have been screened and some of them have been shown to contain pyrrolidine alkaloids. Cuskhygrine has been found in the roots of three Datura species and stachydrine has been obtained from Capparis spinosa3 The structure of trichostachine (1) Piper trichostachyon) has been elucidated by spectral means and confirmed by synthesis. Ficine (5), an interesting flavonoid alkaloid, has been synthesised. Friedel-Crafts reaction between... 

Flavonoids, alkaloids, and vitamins C and E as components of some species of Elaegnaceae family plants 01KPS87. 

Tables 1,2 summarise the compounds of this type so far isolated from the plant kingdom and it can be seen that there is no discernible pattern in the distribution of chromone alkaloids in the flowering plants. The flavonoidal alkaloids have been isolated from several different plant families but often only from one genus of a family. Many genera and species related to those yielding this type of alkaloid have not been investigated so further studies may enable patterns to be discerned.

Only two novel flavonoidal alkaloids have been reported since the previous overview [1]. 

---