We have reviewed the natural compounds present in rice (Oryza sativa L) plant. Several classes of compounds (diterpenoids, steroids and steroidal glycosides, aliphatic, anthracene derivatives, flavonoids and other classes of compounds) have been reported from the hulls and other plant parts of this genus. Many compounds identified from rice hulls, rice leaves and stems possess herbicidal activities. The rice hull is most abundant agricultural product in rice growing areas, possessing phytoalexin substances that could serve as natural herbicides to suppress weeds. Such information indicates that the inhibitory substances from rice hulls could potentially control weeds in an environmentally acceptable and sustainable manner.
Allelochemicals, allelopathic natural substances, herbicidal agents, Oryza sativa, rice composition
