Amaranthus caudatus

The arsenal of plant defense peptides contains members capable of binding carbohydrate residues, namely /31-4 linked A -acetyl glucosamine residues that form the biopolymer chitin. The actual mode of action remains unclear. Antifungal and antimicrobial activity has been shown in vitro. For example Ac-AMP2 is a small disulfide-rich chitin-binding peptide isolated from the seeds of Amaranthus caudatus with antimicrobial activity. It differs from Ac-AMP 1 by one additional arginine residue at the C-terminus. The structure was determined by NMR and contains a cystine knot motif. Ac-AMP2 displays a so-called hevein domain partly... 

We found that the seeds of several other plants (e.g. of Raphanus sp. or of Amaranthus caudatus) are much more sensitive against inhibitors from oat caryopses than oats itself. This means that germination of such seeds is effectively inhibited if they are in the immediate neighborhood of oat caryopses even if germination of oats itself can take place. Oats are more active in allelopathy than other cereals (2). 

Table II. Inhibition of Germination of Amaranthus caudatus Seeds by Carboxylic Acid Methyl Esters...

DiOH-4 -OMe 8-Me C17H16O5 300 8-Methylisosakuranetin Amaranthus caudatus Amaranthaceae Flower 57... 

Amaranthus caudatus Leptospermum polygalifolium ssp. polygalifolium Leptospermum polygalifolium ssp. polygalifolium Trifolium alexandrium... 

Amaranthus caudatus L. Wei Sui Xian (Amaranth) (leaf) Betaine.48 A tonic. 

Amaranthus caudatus, A. paniculatus, Astragalus complanatus, A. henyri, A. hoantchy, A. membranaceus, A. melilotoides, A. mongholicus, A. reflexistipulus, A. sinensis, Firmiana simplex, Lycium chinense,... 

Since the use of techniques to measure IAA, bioassays have been important to discover PGR activity of many other compounds. Several bioassays for the PGR gibberellic acid (GA3) have been developed. One bioassay was based on reduction of amaranthin levels in Amaranthus caudatus (tassel flower) seedlings.63 This method was sensitive to GA3 from 0.01 to 1 mg L"1. GA3 was also bioassayed, based on anthocyanin reduction in tomato (Lycopersicon esculentum L.).62 Reduction of anthocyanin in tomato seedlings was linear from 10"5 to 10 mg L 1, and thus, this latter plant bioassay method was more sensitive. A multitude of bioassays for nonvolatile and volatile plant growth regulator compounds have been developed and their uses and limitations have been discussed.129 Since many allelochemicals have been shown to have relatively weak phytotoxicity (especially compared to herbicides), some of these bioassays that have been developed for detecting and quantitatively measuring PGR activity may be useful in allelopathy. 

Kinsman, L. T., Pinfield, N. J., and Stobart, A. K. 1975. A gibberellin bioassay based on betacyanin production in Amaranthus caudatus seedlings. Planta 127, 149-152... 

Phenyl-l,2,3-triazolo[4,5-d]pyrimidin-7(6//)-one has bactericidal activity against Bacillus subtilis and Staphylococcus aureus (94MI2). 1-Benzyl-4-ethoxycarbonylpiperazinyl-l//-l,2,3-triazolo[4,5-d]pyrimidine almost completely removed cytokinin-stimulated effects in betacyanin synthesis in Amaranthus caudatus cotyledons, growth of radish cotyledons, and retention of chlorophyll in leaf explants (94MI4). Analogs of 117 were used as effective inhibitors of xanthine oxidase (95FA257). 

Amaranthus CBP Ac-AMP2 Amaranthus caudatus Chitin [antifungal]... 

Stobart, A.K. and Kinsman, L.T. (1977) The hormonal control of betacyanin synthesis in Amaranthus caudatus. Phytochemistry, 16,1137-42. 

The mode of substitutions of the molecules may trigger effects on monocots and dicots. Thus, 5-chloro-6-methoxy-2-benzoxazolinone was fovmd to be especially toxic to the monocots Avena sativa, Phleum pratense L., Digitaria sanguinalis (L.) Scop., and Lolium multiflorum Lam. [99]. The dicots Amaranthus caudatus L., Lepidium sativum, and Lactuca sativa were less affected. The molecular reasons for the switch in sensitivity were, however, not discussed. 

Phaseolus lunatus, Amphicarpa bracteata, Griffonia simplicifolia ly Amaranthus caudatus, Irisxhollandica Amaranthus spp., Alocasia indica, Hericium erinaceum Vida cracca... 

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