Which statement is true about alkaloids?

Alkaloids are indeed naturally occurring compounds primarily found in plants, and they can be extracted from these plant sources. This characteristic is what makes the statement about them being naturally occurring chemicals that can be extracted accurate. Alkaloids have a wide range of physiological effects and are known for their potential medicinal properties, functioning as important pharmacological agents in many therapeutic applications.

Key examples of alkaloids include morphine, caffeine, and nicotine, which are derived directly from plants. The extraction process typically involves methods like solvent extraction or acid-base extraction, illustrating that these compounds naturally exist in the environment and do not need to be artificially synthesized.

In contrast, the other statements are not correct. Alkaloids do not exclusively require a chemical reaction for extraction; they can be obtained through straightforward extraction techniques. Additionally, the potency of alkaloids can vary widely, and it cannot be generalized that they are always less potent than synthetic drugs; many alkaloids are highly potent and effective in their pharmacological action.