A nitro compound is defined as a chemical compound that features a nitro group (-NO$_2$) bonded to a carbon atom.

Nitro compounds are synthesized through a process known as nitration. This process involves the reaction of a substrate with nitric acid or a combination of nitric acid and sulfuric acid. During nitration, a hydrogen atom on the carbon chain is substituted with a nitro group. This reaction is usually performed under strictly controlled conditions due to its highly exothermic nature, which poses potential hazards.

In industrial applications, nitro compounds are extensively utilized, particularly in the manufacture of explosives, dyes, and pharmaceuticals. Additionally, these compounds occur naturally in various plants and animals, where they contribute to defense mechanisms. However, it is important to note that nitro compounds can be toxic and may have carcinogenic properties, hence exposure to them should be minimized.

In biological systems, nitro compounds can function as signaling molecules, influencing a range of physiological processes. For instance, nitric oxide (NO) is a notable nitro compound produced by cells in the body. It plays a crucial role in regulating blood pressure, immune responses, and neurotransmission. Furthermore, nitro compounds have been explored as potential therapeutic agents for various diseases, including cancer, cardiovascular conditions, and neurodegenerative disorders.