New Pyridyl and Dihydroisoquinoline Alkaloids Isolated from the Chevron Nemertean .

Nemertean worms contain toxins that are used to paralyze their prey and to deter potential predators. Hoplonemerteans often contain pyridyl alkaloids like anabaseine that act through nicotinic acetylcholine receptors and crustacean chemoreceptors. The chemical reactivity of anabaseine, the first nemertean alkaloid to be identified, has been exploited to make drug candidates selective for alpha7 subtype nAChRs.

Discovery of the Nicotinic Receptor Toxin Anabaseine in a Nemertean.

Nemerteans (also called Nemertines) are a phylum of predominantly marine worms that use toxins to capture prey and to defend themselves against predators. Hoplonemerteans have a proboscis armed with one or more stylets used in prey capture and are taxonomically divided into Order Monostilifera, whose members possess a single large proboscis stylet, and Order Polystilifera, whose members have multiple small stylets. Many monostiliferans contain alkaloidal toxins, including anabaseine, that stimulate and then desensitize nicotinic acetylcholine receptors that are present in all animals.

The nonopioid cholinergic agonist GTS-21 mitigates morphine-induced aggravation of burn injury pain together with inhibition of spinal microglia activation in young rats.

Background: Repetitive opioid use does not always alleviate basal pain, procedural pain, or both after burn injury. Mitigation of burn injury-site pain can be achieved by GTS-21 stimulation of α7-acetylcholine nicotinic receptors (α7AChRs) and reduced microglia activation in rat. We tested the hypothesis that morphine exaggerates burn injury-site pain and GTS-21 alleviates both morphine-induced aggravated burn injury pain and microglia activation.

Interactions of Nereistoxin and Its Analogs with Vertebrate Nicotinic Acetylcholine Receptors and Molluscan ACh Binding Proteins.

Nereistoxin (NTX) is a marine toxin isolated from an annelid worm that lives along the coasts of Japan. Its insecticidal properties were discovered decades ago and this stimulated the development of a variety of insecticides such as Cartap that are readily transformed into NTX. One unusual feature of NTX is that it is a small cyclic molecule that contains a disulfide bond.