Recent aspects of chemical ecology: Natural toxins, coral communities, and symbiotic relationships

Abstract

The discovery of new ecologically active compounds often triggers the development of basic scientific concepts in the field of biological sciences, since such compounds have direct physiological and behavioral effects on other living organisms. We have focused on the identification of natural key compounds that control biologically and physiologically intriguing phenomena. We describe three recent aspects of chemical ecology that we have investigated: natural toxins, coral communities, and symbiotic relationships. Blarina toxin (BLTX) is a lethal mammalian venom that was isolated from the short-tailed shrew. Duckbilled platypus venom shows potent Ca 2+ influx in neuroblastoma cells. The venom of the solitary wasp contains arginine kinase-like protein and is used to paralyze its prey to feed its larva. The ecological behaviors of corals are controlled by combinations of small molecules. The polyol compound symbiodinolide may serve as a defense substance for symbiotic dinoflagellates to prevent digestion of their host animals. These compounds reveal the wonder of nature, in both terrestrial and marine ecological systems.

Bioactive secondary metabolites from symbiotic marine dinoflagellates: symbiodinolide and durinskiols

“…A variety of biologically and physiologically active secondary metabolites of marine origin have been isolated. In particular, huge polyol and polyether compounds composed of a long carbon backbone functionalized by oxygen atoms, referred to as “super‐carbon‐chain compounds (SCC),”1 such as palytoxin, halichondrin, ciguatoxin, and maitotoxin, are some of the most attractive molecules in natural products chemistry 1–7. It has been suggested that the primary producers of such secondary metabolites may be microalgae, bacteria, and fungi, and they are carried through symbiosis, association, a food chain, and other forms of nutrient‐dependency 8–11.…”

Recent insights into natural venoms

“…We collected and stored 1 to 2 μl of venom from each individual. The important problems in this study were: (1) how to inject a microliter of venom into the prey, and (2) what to select as the targeted larva food. We solved problem 1 by devising a microliter syringe, and problem 2 by using only spiders.…”

“…Diverse natural products [1][2][3][4][5][6][7][8][9][10][11][12][13][14] with extraordinary chemical structures and significant biological activities have been isolated and characterized from both marine and terrestrial organisms [15,16], and they have been studied for a long time [17]. Discovery of new compounds with potent activity can develop and even create scientific fields.…”

“…The discovery of new basic compounds holds the key for the advancement of materials science. First, as specific and successful examples, we will describe the recent findings regarding palytoxin (1) and halichondrin B (2). Next, as examples of the power of these naturally occurring organic molecules, we will discuss (1) natural venoms, (2) marine sunscreen, and (3) marine huge molecules.…”

Duck-Billed Platypus Venom Peptides Induce Ca2+ Influx in Neuroblastoma Cells

“…8 Guided by this bioassay, we have identified 11 novel peptides 1-11 ( Figure 1). Here we describe the purification and characterization of these peptides found in the venom.…”