Which of the following substances is a Natural Alkaloid of opium?

Codeine is a natural alkaloid derived from opium, which is obtained from the opium poppy plant (Papaver somniferum). Alkaloids are a class of naturally occurring organic compounds that usually contain basic nitrogen atoms, and many of them have pharmacological effects. Codeine is one of several alkaloids present in opium, along with morphine, which is another well-known natural opiate.

The significance of recognizing codeine as a natural alkaloid lies in its historical and clinical context. It has been used for pain relief and cough suppression, representing a direct compound sourced from nature. Understanding the properties of codeine, including its efficacy, side effects, and potential for addiction, is crucial for drug recognition experts.

In contrast, other substances listed, such as Dilaudid (which contains hydromorphone), oxycodone, and fentanyl, are either semi-synthetic or synthetic opioids. These substances may be derivatives of natural alkaloids but do not fall under the category of natural alkaloids from opium. Therefore, codeine's classification as a natural alkaloid makes it the correct choice in this question.