The 10-Hydroxycamptothecin (10-HCPT) contains a lactone ring structure, which is key in keeping its anticancer activity. When the ring is hydrolyzed and opened, the activity of the 10-HCPT will be significantly reduced or inactivated. The stability of the ring structure of the lactone in the 10-HCPT is strongly related to the pH value. The structure of the lactone ring will be a closed loop when the pH value is less than 5, and the activity of 10-HCPT can be enhanced. When the pH value exceeds 7.4, the lactone ring will be broken, and the hydroxyl lactone will be inactivated. Accordingly, 10-HCPT has poor stability and low aqueous solubility. Nevertheless, previous reports have indicated that the water solubility and stability of 10-HCPT can be improved by complexation with liposomes. Furthermore, the delivery system of the liposome can increase the treatment efficacy of drugs by decreasing renal clearance and prolonging blood circulation[2].
10-Hydroxycamptothecin: An Inhibitor of Topoisomerase I with Antitumor Activity
10-hydroxycamptothecin (10-HCPT) is an inhibitor of topoisomerase I originally isolated from the Chinese tree C. acuminata. 10-HCPT, a member of the camptothecin family, interferes with DNA synthesis by inhibiting the enzyme topoisomerase-I and has a broad spectrum of antitumor activity and less toxicity as camptothecins. However, 10-HCPT is insoluble in both water and physiological acceptable organic solvents and tends to change into its carboxylate form, which shows minimal antitumor activity and several unpredictable side effects. Therefore, appropriate drug delivery systems (DDS) for 10-HPCT have been developed to improve the stability of its lactone form. 10-HCPT is also an important precursor for the synthesis of clinically useful anticancer agents, such as irinotecan[1].
mp 268-270°C loss on drying <1%
therapeutic effects for liver cancer, stomach, and neck cancer and leukemia.
10-Hydroxycamptothecin (10-HCPT), a natural alkaloid derived from camptothecin analogues, has been successfully used to treat various tumors in the clinic, like liver cancer, colorectal cancer, lung cancer, and leukemia. The action of the 10-HCPT on cancer is similar to that of CPT, while the 10-HCPT is safer than CPT. The 10-HCPT can inhibit the DNA synthesis phase by acting on topoisomerase I, suppressing DNA replication and RNA synthesis[2].
[1] Chunjian Zhao. “Determination of Camptothecin and 10-Hydroxycamptothecin in Camptotheca acuminata by LC-ESI-MS/MS.” Analytical Letters 6 1 (2010): 2681–2693.
[2] Ruonan Shuang. “Pharmacokinetics of 10-hydroxycamptothecin–tetrandrine liposome complexes in rat by a simple and sensitive ultra-high performance liquid chromatography with tandem mass spectrometry.” Journal of separation science 43 3 (2019): 569–576.
