Discovery of daphnane diterpenoids with odd-numbered aliphatic side chains in Daphne pedunculata

A research group led by Professor Wei Li of the Department of Pharmacognosy, Faculty of Pharmaceutical Sciences, Toho University, in collaboration with Shenyang Pharmaceutical University in China and Duke University Medical Center in the United States, discovered that Daphne pedunculata, (Thymelaeaceae) contains rare daphnane diterpenoids with odd-numbered aliphatic side chains. Furthermore, these researchers revealed that these compounds inhibit the replication of the human immunodeficiency virus (HIV). This discovery is anticipated to lead to the development of novel HIV therapeutics with excellent anti-HIV activity. The research of this research was published in the “Journal of Natural Medicines” of the Japanese Society of Pharmacognosy on May 23rd, 2024.

Key Points

• Daphne pedunculata (Thymelaeaceae) contains daphnane diterpenoids with odd-numbered aliphatic side chains.
• Daphnane diterpenoids from Daphne pedunculata exhibit potent anti-HIV activity, which is influenced by the length of the aliphatic side chains.
• Further elucidation of the bioactive diterpenoids in plants of the Thymelaeaceae family is expected to contribute to discovery of new anti-HIV drugs.

Summary of Findings
The plant family Thymelaeaceae comprises 53 genera and more than 800 species that are widely distributed worldwide, excluding the polar regions. These plants contain diterpenoids with notable biological activities, including anticancer and anti-HIV activities. Daphne pedunculata is an evergreen shrub endemic to Yunnan Province in China, that blooms yellow flowers from November to December. The research group has previously isolated and structurally determined novel macrocyclic daphnane diterpenoids with anti-HIV activity from D. pedunculata. In this study, two novel daphnane diterpenoids with unusually odd-numbered aliphatic side chains were isolated from D. pedunculata and their anti-HIV activity was elucidated. The results of this study will contribute to further our knowledge of the structure–activity relationship between daphnane diterpenoids and anti-HIV activity, and are expected to lead to the discovery of new drugs for the treatment of HIV infection.