Yamasaki T et al. (2002) J Nat Toxins "Toxicity of tannins towards the free-living nematode Caenorhabditis elegans and the brine shrimp Artemia salina."

Tsukioka J, Mohamed ASA, Mori T, Fujii K, Yamasaki T, Sato M

[J Nat Toxins, 2002]

Toxicities of gallo- and condensed tannins towards the free-living nematode Caenorhabditis elegans is dependent on the tannins' molecular sizes. In the present paper we investigate the toxicity of ellagitannins to C. elegans and the toxicity of ellagi-, gallo-, and condensed tannins to the brine shrimpArtemia salina. Ellagitannins 1 and 2 were isolated from Euphorbia supina and identified as tellimagrandin I and rugosin A methyl ester, respectively. An ellagitannin preparation from Cornus officinalis was chromatographically fractionated into ellagitannins A through H, having different molecular weights and specific rotations. Three of the ten ellagitannins, 2, G, and H produced significant toxicity towards C. elegans, showing the presence of an activity-structure relationship, as opposed to the results from tests of gallo- and condensed tannins. Ellagi-, gallo-, and condensed tannins also produced toxicity in A. salina.

Mohamed ASA et al. (2000) Journal of Pesticide Science "Lethal activity of galo- and condensed tannins against the free-living soil-inhabiting nematode, Caenorhabditis elegans."

Mohamed ASA, Sato M, Islam SQ, Yamasaki T, Mori T

[Journal of Pesticide Science, 2000]

Great amounts of structurally diverse tannins are annually produced. Tannins have been well known as food phytochemicals (e.g. 3T-O-a-L-arabinopyranosyl-ent-epicatechin-(2a->O-7,4a->8)-epicat echin in cacao mass), medicinal properties (e.g. geraniin in Geranium thunbergii as tonic or antidiarrhoic) or tanning materials for leather manufacture (e.g. wattle tannins in Acacia mollissima). Recently, condensed tannin dimers (procyanidins B-1 and B-3) and its polymers were isolated from Pinus densiflora and characterized as members of the oviposition-stimulating multicomponent system in pine for the cerambycid beetle, Monochamus alternatus. Condensed tannins have also been regarded as antifeedants for phytophagous insects. A marine phlorotannin preparation, polymer of phloroglucinol, obtained from the brown alga Sargassum furvellum inhibits growth of the green algae Dunaliella and Enteromorpha spp. This paper describes isolation and identification of gallo- and condensed tannins and their nematicidal acitivity against the soil-inhabiting nematode, Caenorhabditis elegans.