Erythrina species

Alternatively, solvent partition or countercurrent techniques may be applied. In order to obtain an isoflavonoid-rich fraction from Erythrina species (Leguminosae) for further purification work, an organic solvent extract was dissolved in 90% methanol and first partitioned with hexane. The residual methanol part was adjusted with water to 30% and partitioned with t-butyl methyl ether-hexane (9 1). This latter mixture was then chromatographed to obtain pure compounds. ... 

Nkengfack, A.E. et al.. Further flavonoids from Erythrina species, Phytochemistry, 32, 1305, 1993. 

The hybrid species E. x bidwillii elaborated two new alkaloids, erythrinine (21) (24, 25) and the dibenzo[e,/]azonine base erybidine (62), (23, 26) which had not been found in the parent species E. crysta galli and E. herbacea (13). Erythrinine has since been isolated from E. crysta galli (30) and erybidine has been isolated from several other Erythrina species (12, 27, 30, 31). 

Examination of old world Erythrina species by GC-MS has revealed the existence of a larger variety of 11-oxygenated alkaloids 23-31 (see Fig. 2), including examples with 11-oxo functions. The assignment of the structures of these compounds rests entirely on MS evidence (12) (see Section II,C,2c). 

Only two normal Erythrina alkaloids have been isolated from Cocculus species, dihydroerysodine (47) (75) and dihydroerysovine (44), the latter recently from C. trilobus (57). Neither alkaloid has been found in Erythrina species. The structure 44 for dihydroerysovine was deduced from the spectroscopic evidence and by methylation using diazomethane to give the known dihydroerysotrine (38). The positions of the aromatic substituents were determined by detailed NMR experiments using NOE and INDOR techniques (see Section II,C,2d). 

Many Erythrina alkaloids possess curare-like action. Alkaloidal extracts from different parts of Erythrina species have been used in indigenous medicine, particularly in India (176). Many pharmacological effects, including astringent, sedative, hypotensive, neuromuscular blocking, CNS depressant, laxative, and diuretic properties, have been recorded for total alkaloid extracts, although not all these properties can be associated with the ery-thrinane structure alone (38, 177, 178). 

The natural occurrence of hypaphorine is probably not confined to Erythrina species. Von Lippmann (29) isolated from beet shoots a substance with the appropriate physical and analytical properties which,... 

Erythrina isoquinolines (Phe C5N C4N C6 ) Erysonine, erysotrine, erythratidine, a-erythroidine and P-erythroidine (Erythrina species (Fabaceae) curare-like neuromuscular blockers). 

Three reports describing exhaustive chemotaxonomic and chemical investigations of a large number of Erythrina species have appeared. " In the first study, the seeds of 78 of the 107 known species were examined by paper chromatography and electrophoresis for alkaloid content. Interestingly, sections Breviftorae and Edules... 

Erythrina alkaloids, which are known to arise biogenetically from benzyl-tetrahydroisoquinolines, are found to occur in numerous Erythrina species of the family Fabaceae (Leguminosae), the only exception being their presence in the genus Cocculus (Menispermaceae) (55). Erythrina alkaloids are of wide interest because of their remarkable physiological action. 

In a study of five different species of Erythrina collected from different countries, Barton, Widdowson, and co-workers reported the isolation of several new and known alkaloids from two Sri Lankan Erythrina species. The seeds of Erythrina fusca Lour, contained erysotrine (56). Erysotrine... 

Preliminary studies of the alkaloid content of the leaves of four Erythrina species revealed the presence of a- and 6-er3 hroidines (1,2) in E. berteroana, E. poeppigiana,and E. salviiflora but not in E. macrophylla. 

Traditionally, Erythrina species have found use amongst different communities for various ailments. The bark of E. fusca and E. indica, for example, has been used for the treatment of fever, malaria, rheumatism, toothache, boils and fractures. Boiled roots of the same were taken internally as a remedy for beriberi. In Kenya, a concoction of dried bark of E. ahyssinica has been used for the treatment of trachoma (oral) and elephantiasis (external) and its roots against malaria and syphilis, while the pounded green stem bark is taken as an antihelminthic [3]. The water extract of flowers of E. americana have been used in Mexico for the treatment of insomnia. The resl of other documented traditional medicinal uses are listed in Table 1. 

The seeds of Erythrina species are known to contain toxic alkaloids, as well as blood clotting substances, which may be of value in the treatment of thrombosis. The seeds, stem and root bark of some Erythrina species have been used also to stupefy fish, as narcotic, purgative, and diuretic [1,4], while crushed seeds of some have been used as rat poison. All the Erythrina species examined have yielded alkaloids, mostly of the erythrinaline type, having the curare like poisoning action [1,4]. Several of the more common species are used for decorative purposes in gardens and city streets. 

Table 1 Elhnomedicinal Application of Some Erythrina Species (NAPRALERT, 2004)...

Table 3 Liquiritigenin Derivatives from Erythrina Species...

It is interesting to note that most common activity that daidzein and its derivatives exhibit seems to be predominantly antimicrobial (Table 13). Daidzein 41, a possible precursor for 5-deoxyisoflavones, has been reported in several Erythrina species [38-40,76,94-96] and is a well-known dietary phytoestrogen [13b]. It has been reported also to exhibit weak to moderate antibacterial activity and weak radical scavenging properties on the DPPH radical [38-39J. 8-prenyldaidzein 42, so far reported only ill two Erythrina species [21,95], was found lo be active against S. aureus (MIC 10.5 pg/ml, tetracycline 0.1 pg/ml, erythromycin 0.2 pg/ml), B. subtilis (10.5 ftg/ml, tetracycline 0.2 pg/ml) and Mycobacterium smegmatis (12.5 pg/ml,... 

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