9-Dihydro-13-acetylbaccatin III (9-DHAB)
A paclitaxel intermediate isolated from the Canadian yew tree (Taxus canadensis)
9-dihydro-13-acetylbaccatin III, a.k.a. 7,9-deacetylbaccatin VI, is the most abundant taxane found in the Canadian yew tree (Taxus canadensis) (Zamir, et al.). Numerous patents exist for converting 9-dihydro-13-acetylbaccatin III into paclitaxel, an anti-mitotic product with potent anticancer activity, which is also found in yew trees.
Biological Activity:9-dihydro-13-acetylbaccatin III is the most abundant taxane found in the Canadian yew tree (Zamir, et al., 1995).
Taxanes disrupt mitosis by preventing microtubule destabilization and spindle fiber formation in animal cells (Molè-Bajer, 1983). As a consequence of this mechanism, yew trees are slow growing organisms. Without mitosis, cells, especially cells with a high replication rate such as tumor cells, cannot divide. Taxanes are currently being investigated as possible treatment for certain cancers, and paclitaxel is currently approved by the FDA for treatment of AIDS-related Kaposi sarcoma, breast cancer, non-small cell lung cancer, and ovarian cancer (National Cancer Institute, 2012).
References:Elmer W, Mattina M and MacEachern G. (1994) Sensitivity of plant pathogenic fungi to taxane extracts from ornamental yews. Phytopathology. 84(10), 1179-1185.
Molè-Bajer J and Bajer A. (1983) Action of Taxol on Mitosis: Modification of Microtubule Arrangements and Function of the Mitotic Spindle in Haemanthus Endosperm. Journal of Cell Biology. 96, 527-540.
National Cancer Institute. (2012) Cancer Drug Information: Paclitaxel. www.cancer.gov.
Zamir L, Nedea M, Zhou Z, Bélair S, Caron G, Sauriol F, Jacqmain E, Jean F, Garneau F and Mamer O. (1995) Taxus canadensis taxanes: structures and stereochemistry. Canadian Journal of Chemistry. 73(5), 655-665.