Charantin is a chemical substance obtained from the Asian bitter melon (Momordica charantia), reputed to be responsible for the hypoglycaemic properties of those plants. It was identified by Lolitkar and Rao in 1960. It was also found in the similar African species M. foetida, by A. Olaniyi in 1975, under the name foetidin.
Charantin is actually a 1:1 mixture of two steroidal saponins, β-sitosteryl glucoside (C
6) and 5,25-stigmasteryl glucoside (C
6). It is a whitish crystalline substance, neutral and tasteless, melting at 266–268 °C. It is sparingly soluble in water or other highly polar solvents, as well as in apolar solvents like hexane, but is soluble in ether, ethanol and methanol, and can be efficiently extracted from the plant by pressurized ethanol or acetone at 100 °C.
- napin, another 7.8 kDa peptide isolated from bitter melon seeds.
- M. M. Lolitkar and M. R. Rajarama Rao (1962). "Note on a Hypoglycaemic Principle Isolated from the fruits of Momordica charantia". Journal of the University of Bombay 29: 223–224.
- Raman, A.; Lau, C. (1996). "Anti-diabetic properties and phytochemistry of Momordica charantia L. (Cucurbitaceae)". Phytomedicine 2 (4): 349. doi:10.1016/S0944-7113(96)80080-8.
- Olaniyi, A. A. (1975). "A neutral constituent of Momordica foetida". Lloydia 38 (4): 361–362. PMID 1186439.
- Pitipanapong, J.; Chitprasert, S.; Goto, M.; Jiratchariyakul, W.; Sasaki, M.; Shotipruk, A. (2007). "New approach for extraction of charantin from Momordica charantia with pressurized liquid extraction". Separation and Purification Technology 52 (3): 416. doi:10.1016/j.seppur.2005.11.037.
- Parkash, A.; Ng, T. B.; Tso, W. W. (2002). "Purification and characterization of charantin, a napin-like ribosome-inactivating peptide from bitter gourd (Momordica charantia) seeds". The journal of peptide research : official journal of the American Peptide Society 59 (5): 197–202. PMID 11966976.