Liquid Chromatographic Analysis of Cinchona Alkaloids in Beverages

Abstract

A method for the determination of Cinchona extract (whose main components are the alkaloids cinchonine, cinchonidine, quinidine, and quinine) in beverages by liquid chromatography was developed. A beverage with an alcohol content of more than 10% was loaded onto an OASIS HLB solid-phase extraction cartridge, after it was adjusted to pH 10 with 28% ammonium hydroxide. Other beverages were centrifuged at 4000 rpm for 5 min, and the supernatant was loaded onto the cartridge. The cartridge was washed with water followed by 15% methanol, and the Cinchona alkaloids were eluted with methanol. The Cinchona alkaloids in the eluate were chromatographed on an L-column ODS (4.6 mm id × 150 mm) with methanol and 20 mmol/L potassium dihydrogen phosphate (3 + 7) as the mobile phase. Cinchona alkaloids were monitored with an ultraviolet (UV) detector at 230 nm, and with a fluorescence detector at 405 nm for cinchonine and cinchonidine and 450 nm for quinidine and quinine (excitation at 235 nm). The calibration curves for Cinchona alkaloids with the UV detector showed good linearity in the range of 2400 μg/mL. The detection limit of each Cinchona alkaloid, taken to be the concentration at which the absorption spectrum could be identified, was 2 μg/mL. The recovery of Cinchona alkaloids added at a level of 100 μg/g to various kinds of beverages was 87.6-96.5%, and the coefficients of variation were less than 3.3%. A number of beverage samples, some labeled to contain bitter substances, were analyzed by the proposed method. Quinine was detected in 2 samples of carbonated beverage.

Enzymatic Activities of CYP3A4 Allelic Variants on Quinine 3-Hydroxylation In Vitro

“…Quinine is recommended as the treatment for uncomplicated malaria, particularly in the first trimester of pregnancy (W. H. Organization, 2015), or is used to treat severe malaria if the first-line drug fails or is not available (W. H. Organization, 2015). Further, quinine is used as a flavor modifier in beverages such as bitter lemon and tonic water (Horie et al, 2006; Bel et al, 2009), and is an ingredient of some lotions and shampoos. Quinine is eliminated over 80% via hepatic biotransformation and is excreted unchanged about 20% by the kidneys.…”

Quantitative determination of major alkaloids in Cinchona bark by Supercritical Fluid Chromatography

“…It became the primary remedy against this disease worldwide, and only after World War 2 synthetic antimalarials like chloroquine replaced the natural product [1]. However, due to increasing resistances and also availability issues quinine is still relevant for malaria treatment today [2]; besides that the compound is added to beverages as bitter agent [3], serves a catalyst in asymmetric organic synthesis [4], or acts as chiral selector in stationary phases [5]. The alkaloid pattern in Cinchona bark is rather complex with more than 30 known representatives [6].…”

“…is based on a photometric determination of quinine (348 nm) and cinchonine-type (316 nm) alkaloids. Research papers mainly emphasized on the separation of the dominant representatives utilizing TLC [7], isotachophoresis [8], aqueous [9] and non-aqueous CE [10], vibrational spectroscopy [11], NMR [12] and HPLC [3,6,13–16]. For example, Hoffmann et al utilized a chiral strong cation exchange material to excellently resolve eight Cinchona alkaloids in 15 min, yet an application to plant material is missing [16].…”

A new trick for an ancient drug: quinine dissociates antiphospholipid immune complexes

“…5 Quinine usage extends to the beverage industry, where it is used as a flavor modifier. 6,7 In the less-regulated supplement industry or homeopathic medicines, quinine can be found in products containing cinchona bark for its antimalarial properties and other purported therapeutic applications. 8 Although evidence for quinine usage in autoimmune diseases is lacking, its structural similarities to the synthetic antimalarial hydroxychloroquine (HCQ) make it an interesting candidate for investigating its pharmacologic effects in relation to antiphospholipid syndrome (APS).…”