Scientists from the Scripps Research Institute in Jupiter, Florida have synthesized a rare natural product isolated from the bark of a plant widely used in traditional medicine, that has potential as a non-narcotic pain killer. Their findings appear online in the journal Nature Chemistry (paid subscription required).
The study defined a way to generate quantities of conolidine, a rare natural product. Conolidine is derived from the bark of a common tropical flowering plant Tabernaemontana divaricata, also known as crepe jasmine (pictured right). Extract from the leaves has been used in traditional medicine in Asia as an anti-inflammatory applied to wounds, while the root has been chewed to fight the pain of toothache.
The study also suggests that synthetic conolidine, when tested on mice, is an analgesic as effective as morphine in alleviating inflammatory and acute pain, with few, if any, side effects. While widely prescribed for pain, morphine has a number of adverse side effects that range from the unpleasant to the lethal, including nausea, chronic constipation, addiction, and breathing depression.
Conolidine is a rare member of a larger class of natural products, called C5-nor stemmadenines, some of which have been described as opioid analgesics. Despite the potential value of conolidine and related C5-nor stemmadenines as leads for therapeutics, efficient methods to prepare these molecules have not been developed. Glenn Micalizio from the Scripps chemistry faculty created the first lab-based synthesis of those molecules.
The pharmacological assessment, conducted by Scripps’s Laura Bohn, showed that the new synthetic compound has effective analgesic properties. In various models of pain, the synthetic compound suppressed acute pain and inflammatory-derived pain, two key measures of efficacy. The compound also passed easily through the blood-brain barrier, and was present in the brain and blood at relatively high concentrations up to four hours after injection.
The compound has shown few, if any, side effects. “The lack of side effects makes it a very good candidate for development,” Bohn says. “On the other hand,” she adds, “if there were side effects, they might provide additional clues as to how the compound works at the molecular level.”
Read more: New Initiative to Speed Pain Treatments
Photo: Srinivasan G/Flickr
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