Autonomous and induced pterocarpanoid formation in the leguminosae

The occurrence of pterocarpanoids (either ‘autonomously formed’ or ‘induced’) is surveyed and a chemotaxonomic evaluation is made of this and new data. A hypothesis is proposed for their biosynthetic relationships involving a pterocarp-6a-en intermediate.     

N-methyltyramine,a biologically active amine in Acacia seeds

The seeds of Acacia species belonging to the ‘pennata’ group characteristically contain N-methyltyramine (approximately 0.5% dry weight). Like tyramine, N-methyltyramine increases blood pressure in the anaesthetized rat, relaxes guinea pig ileum and increases both the force and rate of contraction of guinea-pig right atrium by inducing the release of noradrenaline.     

A stilbene and two flavanones from Derris rariflora

The wood of the vine Derris rariflora (Leguminosae-Lotoideae) contains 3,5-dimethoxy-4-prenylstilbene, (2S)-5,7-dihydroxy-6-prenylflavanone and (2S)-5-hydroxy-7-methoxy-6-prenylflavanone.     

A new amine,stizolamine, from Stizolobium hassjoo

A new pyrazine derivative, stizolamine (1-methyl-3-guanidino-6-hydroxymethylpyrazin-2-one), has been isolated from seeds of Stizolobium hassjoo. This amine, which has a blue fluorescence, gives guanidine, N-methyl-alanine, oxalic acid, alanine and glycine on treatment with 6 N HCl. The permanganate oxidation product of stizolamine is 4-amino-6-methylcarbamoyl-1,3,5-triazine-2-carboxylic acid.     

Acacipetalin from six species of Acacia of Mexico and Texas

Acacipetalin is the principal cyanogenic glycoside in Acacia chiapensis, A. cochliacantha, A. hindsii, A. macracantha, A. schaffneri var. schaffneri (all from Mexico) and A. schaffneri var. bravoensis (Texas).     

Alkaloid chemotaxonomy of the genus Sophora

Cytisine and matrine alkaloids detected in Sophora species have been used to classify the genus chemotaxonomically.     

l-3-(3′-Carboxy-4′-hydroxyphenyl)alanine (3-carboxytyrosine) in seeds of Neonotonia wightii (Glycine wightii) and its possible systematic significance

l-3-(3′-Carboxy-4′-hydroxyphenyl)alanine (3-carboxytyrosine) constitutes 3% of the seeds of Neonotonia wightii (Glycine wightii); it has also been detected in the seeds of 3 species belonging to 2 other genera of the Glycineae. The systematic significance of these findings is discussed.     

A revised classification of the tribe Phaseoleae (Leguminosae: Papilionoideae), and its relation to canavanine distribution

The subtribal classification of the tribe Phaseoleae has drifted into disorder since Bentham's (1865) scheme in the Genera Plantarum. A revised classification is here proposed, which for the first time accounts for all of the currently recognized genera. This classification has seven subtribes: Cajaninae, Diocleinae, Kennediinae, Phaseolinae, Glycininae, Ophrestiinae, and Erythrininae, of which the Ophrestiinae is new. A survey for the free amino acid, canavanine, shows that it is most often present in the Diocleinae and Kennediinae and frequently absent in the rest of the tribe.     

Some highly proteinaceous Acacia gum exudates of the subseries Juliflorae

Analytical data for the gum exudates from Acacia difficilis, A. dimidiata, A. eriopoda, A. maidenii, A. stipuligera, A. torulosa and A. tumida are presented. Of these, five are highly proteinaceous; they also have high methoxyl contents and very low rhamnose contents. In contrast, A. dimidiata shows no unusual analytical parameters, and A. maidenii gum has alowarabinose content and a high rhamnose content, thus having a sugar composition of the type first observed in the gum from A. saligna. The gum from A. maidenii is also of interest as its analytical data are closely similar to those for A. longifolia, the only other tetramerous member of the subseries Juliflorae to have been studied. The data reported extend even further the unusual ranges of analytical parameters found within the Juliflorae, and confirm its great heterogeneity and chemotaxonomic interest.     

Biosynthesis of stizolamine in Stizolobium hassjoo

In Stizolobium hassjoo, stizolamine is located in seeds and pericarps and is not found in mature leaves, stems and roots. The content of stizolamine in seeds and the fruits increases with their maturation but do not correlate with their dry weights. A feeding experiment showed that guanosine triphosphate [U-¹⁴C] is effectively incorporated into stizolamine in pericarps.     

Systematic significance of canavanine in the Papilionoideae (faboideae)

Canavanine is a nitrogen-rich non-protein amino acid, with a supposedly dual role of food storage and defence in seeds and seedlings. It seems to be unique to Leguminosae subfamily Papilionoideae although it does not occur in all species or genera. This report extends the previous surveys for canavanine to 1200 species in 240 genera (including first records for 70 genera) and assesses the systematic and ecological significance of its distribution.     

The proteinaceous components of the gum exudates from some phyllodinous Acacia species

Acacia gum exudates are proteinaceous polysaccharides; their protein content ranges from ca 0.2 to 45%.The data presented show that the amino acid compositions of the gums from 12 phyllodinous species (10 from Bentham's sub-series Uninerves racemosae, two from sub-series Juliflorae) also vary considerably, particularly in respect of their hydroxyproline content (55 residues per 1000 residues in A. aestivalis gum, 287 residues per 1000 in A. saliciformis gum). The proportions of some other amino acids, e.g. alanine, aspartic acid, proline and serine also vary considerably, but the proportions of others, e.g. cystine, methionine, histidine, threonine, tyrosine and valine, are remarkably constant. The amino acid composition of gums with a very low protein content (e.g. A. victoriae and A. mycrobotrya) is similar to that for a highly proteinaceous gum (A. tumida). There are, however, considerable differences between the amino acid compositions of the gums from A. saligna and A. pycnantha (South African and Western Australian specimens). This strengthens previous chemotaxonomic evidence, based on the polysaccharide parameters of their gums, that these two species are not as close taxonomically as was originally believed from morphological considerations.     

The isopentenyl isoflavone luteone as a pre-infectional antifungal agent in the genus Lupinus

The prenylated isoflavone luteone has been isolated from healthy leaves of Lupinus albus and 11 other lupin species. Evidence is presented that this compound occurs as a leaf surface constituent. In vitro tests indicate that luteone and a second unidentified isoflavone frorn L. albus possess antifungal activity sufficient to support their proposed role as pre-infectional resistance factors. No evidence was obtained to suggest that phytoalexins were produced by the fungus-infected leaves of L. albus.     

Partial structural studies of four Acacia gum exudates of the series phyllodineae

Methylation and hydrolysis studies have shown that gum specimens from Acacia difformis, A. mabellae, A. retinodes and A. rubida, which belong to Bentham's Series I (Phyllodineae), subseries 6F (Uninerves Racemosae), are similar structurally to those from A. podalyriifolia and A. pycnantha. This is further evidence that A. cyanophylla, which was placed next to A. pycnantha by Bentham, is atypical of the Series I Acacias.     

The composition of eight Acacia gum exudates from the series Gummiferae and Vulgares

An analytical study has been made of gum specimens from Acacia hebeclada, A. kirkii, A. newbrownii and A. reficiens (all of the series Gummiferae) and of Acacia erubescens, A.fleckii, A. mellifera ssp. mellifera and A. mellifera ssp. detinens (all of the series Vulgares). The data obtained give further support for the main chemotaxonomic differences between the Gummiferae and Vulgares species recorded previously. In addition, two of the species studied have exceptional features; the gum exudate from A. hebeclada contains 9.4% of nitrogen; that from A. erubescens contains 12% of glucose.