Determination of coenzyme Q10 and Q9 in vegetable oils

A new sensitive and selective method has been developed for the quantification of the total coenzyme Q9 (CoQ9) and coenzyme Q10 (CoQ10) concentration in vegetable oil samples. The coenzyme Q fraction is isolated by solid-phase extraction (SPE) on amino phase eluting with a mixture of heptane:ethyl ether. The organic solvent is evaporated under nitrogen, and the residue is dissolved in a mixture of acetonitrile:tetrahydrofuran and finally is analyzed by reverse-phase high-performance liquid chromatography with a mass detector. The sensitivity of the method is based on the high efficient formation of the radical anions [M (-.)] of CoQ9 and CoQ10 by negative atmospheric pressure ionization. Interferences are minimized by using mass detection of the [M (-.)] ions ( m/ z = 797.5 for CoQ9 and m/ z = 862.5 for CoQ10) in selective reaction monitoring mode ( m/ z = 797.5 --> m/ z = 779.5 and m/ z = 862.5 --> m/ z = 847.5) using a triple-quadrupole mass spectrometer. The method was successfully applied to sunflower, soybean, and rapeseed oils, with a limit of quantification of 0.025 mg/kg for both compounds.     

Determination of coenzyme Q10, coenzyme Q9, and melatonin contents in virgin argan oils: comparison with other edible vegetable oils

Virgin argan oil possesses high antioxidant capacity (AC), which may be partially explained by its high content in antioxidant molecules such as polyphenols and tocopherols. However, the content in other antioxidant molecules, for example, coenzyme Q10 (CoQ(10)), coenzyme Q9 (CoQ(9)), and melatonin (Mel), which have been identified in other edible vegetable oils, have not been evaluated in virgin argan oil. Consequently, it was decided to evaluate the contents of CoQ(10), CoQ(9), and Mel in virgin argan oils and compare the results to those obtained in extra virgin olive oils and some varieties of seed oils. By the use of sensitive HPLC-EC/F methods, the results showed that virgin argan oil is a rich source of CoQ(10) and Mel, but no CoQ(9) was detected. Extra virgin olive oil showed higher levels of CoQ(10) and lower levels of Mel than virgin argan oil. Between the seed oil samples, only virgin soybean oil showed higher CoQ(10) and Mel levels than virgin argan oil. The results may be relevant for the contribution of CoQ(10) and Mel to the biological activities of virgin argan oil.     

Optimization in the preparation of coenzyme Q10 nanoliposomes

The optimal formulation of coenzyme Q10 (CoQ10) nanoliposomes and the feasibility of production in a pilot scale were investigated. The nanoliposomes were prepared by ethanol injection and sonication techniques for a desired vesicle size in the laboratory. Optimization of formulation in the preparation of CoQ10 nanoliposomes was achieved by an orthogonal array design. The best formulation was found to be phospholipid/CoQ10/cholesterol/Tween 80 (2.5:1.2:0.4:1.8, w/w) with phosphate buffer solution (pH 7.4, 0.01 M) as the hydration media. The z-average diameter (D(z)) was about 68 nm. The encapsulation efficiency was greater than 95% with a retention ratio higher than 90% and a particle size change lower than 10% after storage at 4 degrees C in the dark for 90 days. CoQ10 incorporation resulted in a dramatic increase of the microviscosity of nanoliposomes and inhibited the peroxidation of phospholipid. The D(z) of CoQ10 nanoliposomes produced in a pilot scale was about 67 nm. Results suggest that the technology developed by this investigation is practical to produce the CoQ10 nanoliposomes with the expected encapsulation quality and stability not only in the laboratory but also in a pilot scale.     

Interaction of coenzyme Q10 with the intestinal drug transporter P-glycoprotein

In clinical trials, patients usually take many kinds of drugs at the same time. Thus, drug-drug interactions can often directly affect the therapeutic safety and efficacy of many drugs. Oral delivery is the most desirable means of drug administration. Changes in the activity of drug transporters may substantially influence the absorption of administered drugs from the intestine. However, there have been a few studies on food-drug interactions involving transporters. It is important to be aware of the potential of food-drug interactions and to act in order to prevent undesirable and harmful clinical consequences. Coenzyme Q10 (CoQ10) is very widely consumed by humans as a food supplement because of its recognition by the public as an important nutrient in supporting human health. Since intestinal efflux transporter P-glycoprotein (P-gp) is one of the major factors in drug-drug interactions, we focused on this transporter. We report here for the first time that CoQ10, which is widely used as a food supplement, affects the transport activity of P-gp.     

复配亚麻籽油和辅酶Q10乳液的制备及表征

亚麻籽油和辅酶Q10都具有水中溶解度低、稳定性差、生物利用度低等缺点。将亚麻籽油和辅酶Q10(coenzyme Q10,CoQ10)同时负载于乳液中,可解决两者的应用瓶颈。使用阿拉伯胶为乳化剂,采用高压均质法制备复配亚麻籽油和CoQ10乳液。采用动态光散射、透射电子显微镜、体外模拟消化、体外释放、稀释稳定性、冻融稳定性、离子强度稳定性、光稳定性和加速氧化稳定性方法对所制备乳液的理化性质进行表征。结果显示,制备的乳液平均粒径为(284±5.6) nm,多分散指数(polydispersity index,PDI)为0.112±0.025,为均匀分散的球形液滴。制备的乳液在模拟小肠液中消化,和亚麻籽油、CoQ10混悬液相比,乳化后亚麻籽油的消化速率和CoQ10的生物可给率明显提高。乳液中CoQ10的释放表现出缓释效果。制备的乳液具有较好的稀释和冻融稳定性。Na^+和Ca^2+会造成乳液Zeta电位的下降,对乳液稳定性影响较大。乳液载体化后CoQ10的光稳定性得到了提高。CoQ10对亚麻籽油具有较好的保护作用。     

Comparison of in-line connected diode array and electrochemical detectors in the high-performance liquid chromatographic analysis of coenzymes Q(9) and Q(10) in food materials

In-line connected electrochemical (EC) and diode array (DAD) detectors were compared in the reversed-phase high-performance liquid chromatographic (RP-HPLC) analysis of coenzymes Q(9) and Q(10) in some food materials (beef steak, beef heart, Baltic herring fillet, and rye flour). Coenzymes Q(9) and Q(10) were extracted from the samples using a 5:1 n-hexane-ethanol mixture. Coefficient of variation (CV%) of quadruplicate or quintuplicate determined samples for coenzymes Q(9) and Q(10) was <10 by both EC detector and DAD. Responses of the detection systems were linear in the range evaluated, 10-200 ng/injection, and had correlation coefficients exceeding 0.999. Recoveries of added coenzymes Q(9) and Q(10) varied 73-105% for DAD and 74-103% for EC detector, respectively. Detection limits for coenzymes Q(9) and Q(10) using the DAD system were 4 and 6 ng/injection, respectively, and 0.2 and 0.3 ng/injection by EC detection. Results derived from the two detection systems were generally similar. However, although EC detector was 20-fold more sensitive, the selectivity was, in some cases, poorer than that of DAD.