title: Ionic derivatives of betulinic acid as novel HIV-1 protease inhibitors.
abstract: Betulinic acid is a natural product possessing abundant and favourable biological activity, including anti-cancer, anti-malarial, anti-inflammatory and anti-HIV properties, while causing minimal toxicity to unaffected cells. The full biological potency of betulinic acid cannot be fully unlocked, however, for a number of reasons, a primary one being its limited solubility in aqueous and biologically pertinent organic media. Aiming to improve the water solubility of betulinic acid without disrupting its structurally related bioactivity, we have prepared different ionic derivatives of betulinic acid. Inhibition bioassays on HIV-1 protease-catalysed peptide hydrolysis indicate significantly improved performance resulting from converting the betulinic acid to organic salt form. Indeed, for one particular cholinium-based derivative, its water solubility is improved more than 100 times and the half maximal inhibitory concentration (IC(50)) value (22 μg mL(-1)) was one-third that of wide-type betulinic acid (60 μg mL(-1)). These encouraging results advise that additional studies of ionic betulinic acid derivatives as a therapeutic solution against HIV-1 infection are warranted.
authors: Department of Natural Sciences, Savannah State University, Savannah, GA 31404, USA. huazhao98@gmail.com
authors: Hua
authors: H
authors: Zhao
authors: Shaletha S
authors: SS
authors: Holmes
authors: Gary A
authors: GA
authors: Baker
authors: Suresh
authors: S
authors: Challa
authors: Himangshu S
authors: HS
authors: Bose
authors: Zhiyan
authors: Z
authors: Song
mesh_terms: D002384:Catalysis; D005998:Glycine / Q000737:chemistry; D016333:HIV Protease / Q000187:drug effects*; D017320:HIV Protease Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D006868:Hydrolysis; D007477:Ions; D009682:Magnetic Resonance Spectroscopy; D053978:Pentacyclic Triterpenes; D012995:Solubility; D014315:Triterpenes / Q000737:chemistry / Q000494:pharmacology*; D000094062:Betulinic Acid
chemical_list: D017320:HIV Protease Inhibitors; D007477:Ions; D053978:Pentacyclic Triterpenes; D014315:Triterpenes; D016333:HIV Protease; C514803:p16 protease, Human immunodeficiency virus 1; D005998:Glycine; D000094062:Betulinic Acid