What type of natural compounds are the largest group of non-nitrogen containing substances?

The largest group of non-nitrogen containing substances among natural compounds is terpenes. Terpenes are a diverse class of organic compounds produced by a variety of plants, particularly conifers, which are characterized by their distinctive aromatic properties. They are primarily made of isoprene units and can form various structures, from simple monoterpenes to complex polyterpenes, contributing to the vast diversity of scents and flavors in nature.

Terpenes play significant roles in plant ecology, including attracting pollinators, deterring herbivores, and serving as allelochemicals that can inhibit the growth of surrounding plants. Additionally, many terpenes have been studied for their medicinal properties, acting as anti-inflammatory, antimicrobial, or antioxidant agents.

While tannins, saponins, and phenolics all represent significant classes of natural compounds, terpenes outnumber these groups in terms of overall diversity and occurrence, making them the largest category of non-nitrogen containing substances. This understanding of terpenes is crucial in fields such as pharmacognosy and herbal medicine, where they are often targeted for their beneficial properties.