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Ants (Hymenoptera, Apocrita, Aculeata, Formicoidea) comprise a well-succeeded group of animals. Like bees and wasps, ants are mostly venomous, having a sting system to deliver a mixture of bioactive organic compounds and peptides. The predatory giant ant Dinoponera quadriceps belongs to the subfamily Ponerinae that includes one of the largest known ant species in the world. In the present study, low molecular weight compounds and peptides were identified by online peptide mass fingerprint. These include neuroactive biogenic amines (histamine, tyramine, and dopamine), monoamine alkaloid (phenethylamine), free amino acids (e.g. glutamic acid and proline), free thymidine, and cytosine. To the best of our knowledge, most of these components are described for the first time in an ant venom. Multifunctional dinoponeratoxin peptide variants (pilosulin- and ponericin-like peptides) were characterized that possess antimicrobial, hemolytic, and histamine-releasing properties. These venom components, particularly peptides, might synergistically contribute to the overall venom activity and toxicity, for immobilizing live prey, and for defending D. quadriceps against aggressors, predators, and potential microbial infection. [ABSTRACT FROM AUTHOR]

Bunodosine 391 (BDS 391), a low molecular weight compound isolated from the sea anemone Bunodosoma cangicum, increases the nociceptive threshold and inhibits inflammatory hyperalgesia. Serotonin receptors are involved in those effects. In this study, we have expanded the characterization of the antinociceptive effect of BDS 391 demonstrating that, in rats: (a) the compound inhibits (1.2-12 ng/paw) overt pain, in the formalin test, and mechanical hyperalgesia (0.6-6.0 ng/paw) detected in a model of neuropathic pain; (b) intraplantar administration of ondansetron, a selective 5-HT3 receptor antagonist, blocks the effect of BDS 391, whereas ketanserin, a 5-HT2 receptor antagonist, partially reversed this effect, indicating the involvement of peripheral 5-HT2 and 5-HT3 receptors in BDS 391 antinociception; and (c) in binding assay studies, BDS 391 was not able to displace the selective 5-HT receptor antagonists, suggesting that this compound does not directly bind to these receptors. The effect of biguanide, a selective 5-HT3 receptor agonist, was also evaluated. The agonist inhibited the formalin's nociceptive response, supporting an antinociceptive role for 5-HT3 receptors. Our study is the first one to show that a non-peptidic low molecular weight compound obtained from a sea anemone is able to induce antinociception and that activation of peripheral 5-HT3 receptors contributes to this effect. [ABSTRACT FROM AUTHOR]

Flowers of the butterfly pea ( Clitoria ternatea) accumulate a group of polyacylated anthocyanins, named ternatins, in their petals. The first step in ternatin biosynthesis is the transfer of glucose from UDP-glucose to anthocyanidins such as delphinidin, a reaction catalyzed in C. ternatea by UDP-glucose:anthocyanidin 3- O-glucosyltransferase ( Ct3GT-A; AB185904). To elucidate the structure-function relationship of Ct3GT-A, recombinant Ct3GT-A was expressed in Escherichia coli and its tertiary structure was determined to 1.85 Å resolution by using X-ray crystallography. The structure of Ct3GT-A shows a common folding topology, the GT-B fold, comprised of two Rossmann-like β/α/β domains and a cleft located between the N- and C-domains containing two cavities that are used as binding sites for the donor (UDP-Glc) and acceptor substrates. By comparing the structure of Ct3GT-A with that of the flavonoid glycosyltransferase VvGT1 from red grape ( Vitis vinifera) in complex with UDP-2-deoxy-2-fluoro glucose and kaempferol, locations of the catalytic His-Asp dyad and the residues involved in recognizing UDP-2-deoxy-2-fluoro glucose were essentially identical in Ct3GT-A, but certain residues of VvGT1 involved in binding kaempferol were found to be substituted in Ct3GT-A. These findings are important for understanding the differentiation of acceptor-substrate recognition in these two enzymes. [ABSTRACT FROM AUTHOR]

The article presents a study which analyzes flower Tulipa gesneriana (Tg) 's co-pigment anthocyanin, iron contents, and the expression of TgVit1 mRNA in 13 cultivars with blue colors. The study adopts a reproduction experiment to identify the same anthocyanin component knows as delphinidin 3-rutinoside. Results show that iron complexation to delphinidin 3-rutinoside causes the blue coloration in tulip petals and flavonol glycosides stabilizes the iron complex.

We previously identified 92 toxin-like peptides and proteins, including pilosulin-like peptides 1–6 from the predatory ant Odontomachus monticola, by transcriptome analysis. Here, to further characterize venom components, we analyzed the venom and venom sac extract by ESI-MS/MS with or without trypsin digestion and reducing agent. As the low-molecular-mass components, we found amino acids (leucine/isoleucine, phenylalanine, and tryptophan) and biogenic amines (histamine and tyramine) in the venom and venom sac extract. As the higher molecular mass components, we found peptides and proteins such as pilosulin-like peptides, phospholipase A2s, hyaluronidase, venom dipeptidyl peptidases, conotoxin-like peptide, and icarapin-like peptide. In addition to pilosulin-like peptides 1–6, we found three novel pilosulin-like peptides that were overlooked by transcriptome analysis. Moreover, pilosulin-like peptides 1–6 were chemically synthesized, and some of them displayed antimicrobial, hemolytic, and histamine-releasing activities. [ABSTRACT FROM AUTHOR]

The methanolic extract and its subfractions from red peony root, the dried roots of Paeonia lactiflora Pallas showed potent antiallergic effects, as inhibition of immunoglobulin E (IgE)-mediated degranulation in rat basophil leukemia (RBL)-2H3 cells. Bioassay-guided fractionation led to the isolation of 16 monoterpene derivatives, including 3 new compounds, paeoniflorol ( 1 ), 4′-hydroxypaeoniflorigenone ( 2 ) and 4- epi -albiflorin ( 3 ), together with 13 known ones ( 4–16 ). The chemical structures of the new compounds were elucidated on the basis of spectroscopic and chemical evidences. Among the isolated monoterpene derivatives, nine compounds showed potent anti-allergic effects and compound 1 was the most effective. A primary structure-activity relationship of monoterpene derivatives was discussed. [ABSTRACT FROM AUTHOR]