{"id":173,"date":"2010-05-26T09:41:05","date_gmt":"2010-05-26T09:41:05","guid":{"rendered":"http:\/\/blogs.hsc.edu\/biology\/?p=173"},"modified":"2023-09-26T14:32:39","modified_gmt":"2023-09-26T14:32:39","slug":"chemical-warfare-at-ground-level","status":"publish","type":"post","link":"https:\/\/blogs.hsc.edu\/biology\/2010\/05\/26\/chemical-warfare-at-ground-level\/","title":{"rendered":"Chemical warfare at ground level"},"content":{"rendered":"

Collaborating with Dr. Tappey Jones in the Chemistry Department at VMI, Dr. Shear has been working on the chemical defenses of soil arthropods. \u00a0Interesting results have included the discovery of compounds new to arthropods, and at least two molecules that have not been found previously in nature.<\/p>\n

Two groups of soil and litter-dwelling arthropods that use chemical weapons for defense are opiliones (harvestmen or daddy-long-legs) and millipedes (thousand-leggers). \u00a0Harvestmen produce their chemicals from a pair of glands near the front of the body, while millipedes have paired glands on most of their many segments. \u00a0The secretions range from the merely unpleasant (aromatic long-chain alcohols and ketones) through the corrosive (hydroquinones and phenolic compounds) to the lethal (hydrogen cyanide). \u00a0In both groups of animals it appears that the nature of the secretions correlates with evolutionary relationships. \u00a0For example, all millipedes of the orders Julida, Spirobolida and Spirostreptida use quinones for defense. \u00a0Harvestmen in the family Sclerosomatidae (our familiar daddy-long-legs) produce alcohols and ketones.<\/p>\n

However, some groups get pretty exotic. \u00a0We have recently identified a complex mixture of compounds from the tiny harvestman Erebomaster acanthina,<\/em> which occurs mostly in caves and crevices in the midwest. \u00a0Components of the secretion include alkaloids like nicotine, but also\u00a0\u00a0benzothiazoles, salicyl alcohol and a coumarin! \u00a0The major component is an alkaloid related to nicotine, anabaseine. \u00a0Anabaseine is being investigated as possible drug for use in treating Alzheimer’s disease; it is also found in the venoms of ants and of ribbon worms.<\/p>\n

One of our local centipedes (Hemiscolopendra marginata<\/em>) has also been investigated. \u00a0We found a recently discovered molecule called jineol, which has highly cytotoxic effects and may be used by the animals to protect their eggs and young against bacterial and fungal infections. \u00a0Dr. Jones and one of his students have developed a new synthetic procedure for jineol and our results will be published later in the Journal of Natural Products. \u00a0It is exciting that we have also found a totally unknown compound accompanying jineol, and Dr. Jones is working with students to elucidate its structure.<\/p>\n

Drs. Shear and Jones will participate in a grant proposal from a colleague at the University of San Diego to continue this work and investigate ways in which it might provide evidence for the evolution of the animals involved. \u00a0While Dr. Jones has already involved students, Dr. Shear is still looking for candidates at Hampden-Sydney to participate in the research. \u00a0Any takers?<\/em><\/p>\n

<\/p>\n

\"Chonaphe<\/a>

Chonaphe armata, a millipede from Idaho, produces lethal hydrogen cyanide from glands on either side of most of its body segments. The bright yellow and black coloration warns potential enemies of the danger.<\/p><\/div>\n

<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

Collaborating with Dr. Tappey Jones in the Chemistry Department at VMI, Dr. Shear has been working on the chemical defenses of soil arthropods. \u00a0Interesting results have included the discovery of compounds new to arthropods, and at least two molecules that … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-173","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/blogs.hsc.edu\/biology\/wp-json\/wp\/v2\/posts\/173","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.hsc.edu\/biology\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.hsc.edu\/biology\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.hsc.edu\/biology\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.hsc.edu\/biology\/wp-json\/wp\/v2\/comments?post=173"}],"version-history":[{"count":1,"href":"https:\/\/blogs.hsc.edu\/biology\/wp-json\/wp\/v2\/posts\/173\/revisions"}],"predecessor-version":[{"id":2272,"href":"https:\/\/blogs.hsc.edu\/biology\/wp-json\/wp\/v2\/posts\/173\/revisions\/2272"}],"wp:attachment":[{"href":"https:\/\/blogs.hsc.edu\/biology\/wp-json\/wp\/v2\/media?parent=173"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.hsc.edu\/biology\/wp-json\/wp\/v2\/categories?post=173"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.hsc.edu\/biology\/wp-json\/wp\/v2\/tags?post=173"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}