Description
Conessine is a naturally occurring steroid alkaloid found in a number of plant species from the
Apocynaceae family, which have been used in traditional herbal medicine as a treatment for amoebic dysentery. In a radioligand-
based high-
throughput screen, conessine demonstrated high affinity for both rat and human histamine H3 receptors (K
is = 5.2 and 24.5 nM, respectively) and high selectivity against histamine receptors H1, H2, and H4. Though conessine potently blocks H3 agonist-
stimulated GTPγS binding in cell-
and tissue-
based functional assays and efficiently crosses the blood-
brain barrier, it has a poor rate of CNS clearance.
Uses
antiamebic, antibacterial, antineoplastic, anesthetic (local)
Uses
Conessine is a steroidal dibasic alkaloid with a rigid steroid-based skeleton. Conessine is a potent and selective histamine H3 receptor antagonist.
Definition
ChEBI: A steroid alkaloid that is con-5-enine substituted by a N,N-dimethylamino group at position 3. It has been isolated from the plant species of the family Apocynaceae.
Biological Activity
Potent and selective histamine H 3 receptor antagonist (pK i values are 7.61 and 8.27 at rat and human H 3 receptors respectively). A steroidal alkaloid that displays in vitro antiplasmodial activity (IC 50 = 1.04 μ M). Also has high affinity for α 2C adrenoceptors (pK i = 7.98).
Purification Methods
It crystallises from acetone, sublimes at 95o/0.01mm and boils at 0.1mm with bath temperature at 220o. The dihydrochloride has m >340o (browns at 235o and decomposes at 338-240o) and has [] D +9.3o (c 2, H2O). [Marshall & Johnson J Am Chem Soc 84 1458 1962, Beilstein 22 III/IV 4382.]
References
[1] BINA S SIDDIQUI. Antimicrobial activity of the methanolic bark extract of Holarrhena pubescens (Buch. Ham), its fractions and the pure compound conessine.[J]. Natural Product Research, 2012, 26 11: 987-992. DOI:
10.1080/14786419.2010.537268[2] De Souza, F.I., Zumiotti, A.V., and Da Silva, C.F. Neuregulins 1-α and 1-β on the regeneration the peripheral nerves[J]. Acta Ortop Bras.
[3] VIRENDRA K DUA. Anti-malarial property of steroidal alkaloid conessine isolated from the bark of Holarrhena antidysenterica.[J]. Malaria Journal, 2013, 12: 194. DOI:
10.1186/1475-2875-12-194[4] LIANG SHEN. High-Throughput Screening and Identification of Potent Broad-Spectrum Inhibitors of Coronaviruses.[J]. Journal of Virology, 2019, 93 12. DOI:
10.1128/jvi.00023-19[5] CHEN ZHAO*. The Alkaloid Conessine and Analogues as Potent Histamine H3 Receptor Antagonists[J]. Journal of Medicinal Chemistry, 2008, 51 17: 5423-5430. DOI:
10.1021/jm8003625
