摘要：Plants are sources of diverse classes of natural products, some of which have biological activity such as phytotoxins, nematocidal, antimicrobial, phytoalexins, provide nutrition to soil microbes and are allelopathic. In fact the chemical compounds that are released from plant organs (i.e. leaves, stem, roots, flowers and seeds), have an effect on the environment and are known as allelochemicals. These allelochemicals comprises of low molecular weight compounds (such as sugars, inorganic ions, vitamins, nucleotides, amino acids and phenolics), as well as high molecular weight substances (polysaccharides and enzymes and other proteins). Furthermore, the allelochemicals from the source plant can enter the environment through leaching, volatilisation, root exudation and seed-coat exudation in order to protect themselves from the threat around them. The aim of this study is to give a picture of different classes of allelochemicals and their properties. Besides, this review will provide an insight regarding the utilisation of the compounds of interest as a growth regulator, antimicrobial, nemati- cidal, and/or natural herbicide. Certainly, this paper will help in promoting green agriculture and controlling pollution caused by synthetic chemicals.
