This volume comprises three reviews. The first describes isolation, structure determination, syntheses, and biochemistry of the low molecular weight compounds of the secretion of exocrine glands of termies with emphasis to pheromones and defensive compounds. The second review describes recent studies on isolation and structure elucidation of bioactive compounds involved in the life cycle and determination of the molecular mechanisms of the developmental events observed in higher plants. The third contribution reports on the current body of knowledge of African propolis, with a particular emphasis on its chemistry and biological activity.