Muitos dos medicamentos prescritos atualmente foram inicialmente descobertos na natureza. A despeito dos avanços da química e dos sofisticados instrumentos utilizados para a síntese combinatorial de novas drogas, os cientistas ainda recorrem à natureza como fonte de inspiração para o desenvolvimento de novos compostos. Uma fração substancial dos medicamentos em uso atualmente foi direta ou indiretamente derivada de compostos bioativos produzidos por plantas e/ou microrganismos. Recentemente, os compostos de baixo peso molecular de origem animal também têm sido objeto de interesse pelas industrias agroquímicas e/ou farmacêuticas.

Os Artrópodes são considerados uma fonte potencialmente muito importante de novas moléculas que oferecem notáveis propriedades tais como: alta eficiência, baixa probabilidade de resistência microbiana, toxicidade limitada e baixa imunogenicidade para o homem.

Aranhas e vespas constituem um grande grupo de Artrópodes presentes na maioria dos ecossistemas terrestres. As secreções tóxicas de aranhas e vespas são utilizadas para paralisar os insetos-presa por paralisia da transmissão sináptica nas junções neuromusculares destes insetos. Esforços consideráveis têm sido realizados para isolar e identificar compostos neuroativos nas secreções de aranhas e vespas, resultando na descoberta de muitas moléculas que bloqueiam os receptores de glutamato e/ou canais de cálcio. Assim, vários destes compostos se tornaram modelos estruturais para o desenvolvimento racional de drogas neuroprotetoras para diferentes desordens neurológicas. As pequenas moléculas orgânicas existentes em muitas das secreções tóxicas de aranhas e vespas são candidatos naturais à bioprospecção de compostos-líderes para o desenvolvimento de drogas de uso neuroterapêutico e/ou como bioinseticidas seletivos.

----

Arthropods are the largest and the most diverse group of living animals, accounting for over 70% of all known species. They have adapted remarkably well to many different environments of earth as they have potentially been confronting many different types of adversities in the course of evolution and evolving complex cell cycle regulatory mechanisms during the last 500 million years. They have evolved powerful chemical defense systems, since compounds prevent actions of infectious microorganisms until those causing lethal actions against their enemies; these defense systems rely mainly on the biosynthesis of a series of small molecules with predetermined pharmacological activities.

The most of medicines prescribed currently were first discovered in the nature. Nowadays, despite the advanced chemistry and sophisticated instruments for churning out new drugs, scientists still turn to nature for inspiration in developing novel compounds while imperiled forests and/or endangered organisms lasts. A substantial fraction of the medicines currently in use were derived, directly or indirectly, from bioactive compounds produced by microorganisms or plants. Recently, low molecular weight compounds of animal origin have been also subject of a keen interest of the pharmaceutical, agrochemical and bioprospection companies. Historically, initial interest in molecular and mechanistic studies of low molecular weight toxic compounds from Arthropods was to develop means to understand, to prevent or to reverse their toxic actions. Subsequently became apparent that the potent and specific interactions of many of these toxic compounds with their molecular targets made them useful probes of critical process in mammalian cells.

Arthropods provide access to a vast source of potentially important and novel molecules which offer remarkable properties such as high efficacy, low probability of resistance by the micro-organisms, limited toxicity and immunogenicity to the men.

Spiders and wasps constitute a large group of Arthropods present in the most of ecosystems of earth, since the deserts to the wet darkness of the rain forests, since the beaches to the heights of the mountains. The toxic secretions of many spiders and wasps were demonstrated to paralyze their insect-prey by blocking the process of glutamatergic synaptic transmission at the prey’s neuromuscular junctions . Accordingly, considerable research efforts have been mounted to isolate and identify neuroactive compounds in these secretions, resulting in the discovery of many peptides and small molecules which block glutamate receptors and/or calcium channels. Thus, the secretion of many of these animals proved to be useful tools for physiological studies of neuronal function, and several of the neurotoxic compounds produced by their defensive/aggressive secretions may become structural models for the rational development of neuroprotective agents for different neurological disorders. Thus, the small organic molecules occurring in these secretions seems to be natural candidates to be mined in the search for leader compounds for development of neurotherapeutical medicine drugs.