Parkinson’s disease (PD) is the most common age-related movement disorder characterized by the progressive loss of nigrostriatal dopaminergic neurons. To date, PD treatment strategies are mostly based on dopamine replacement medicines, which can alleviate motor symptoms but do not slow down the progression of neurodegeneration. Thus, there is a need for disease-modifying PD therapies. The aim of this work was to evaluate the neuroprotective effects of the novel compound PA96 on dopamine neurons in vivo and in vitro, assess its ability to alleviate motor deficits in MPTP- and haloperidol-based PD models, as well as PK profile and BBB penetration. PA96 was synthesized from (1R,2R,6S)-3-methyl-6-(prop-1-en-2-yl) cyclohex-3-ene-1,2-diol (Prottremin) using the original three-step stereoselective procedure. We found that PA96: (1) supported the survival of cultured näive dopamine neurons; (2) supported the survival of MPP⁺-challenged dopamine neurons in vitro and in vivo; (3) had chemically appropriate properties (synthesis, solubility, etc.); (4) alleviated motor deficits in MPTP- and haloperidol-based models of PD; (5) penetrated the blood–brain barrier in vivo; and (6) was eliminated from the bloodstream relative rapidly. In conclusion, the present article demonstrates the identification of PA96 as a lead compound for the future development of this compound into a clinically used drug.

Для внедрения субстанции в медицинскую практику в рамках доклинических испытаний необходимо доказательство ее чистоты. Одним из показателей контроля качества субстанции является содержание остаточных органических растворителей, которые могут влиять на фармакологическую активность лекарственного препарата. В ходе синтеза и выделения субстанции используют четыре растворителя: дихлорметан, этилацетат, метил-трет-бутиловый эфир (МТБЭ), н-гексан. В работе предложено два способа определения остаточных органических растворителей методом газовой хроматографии в субстанции (2R,4R,4аR,7R,8аR)-4,7-диметил-2-(тиофен-2-ил)октагидро-2Н-хромен-4-ол — с вводом газовой пробы и разделением определяемых компонентов на коммерческой капиллярной колонке HP-5ms (30 м × 0,35 мм × 0,25 мкм); с вводом жидкой пробы и разделением на капиллярной колонке (30 м × 0,32 мм × 0,30 мкм), заполнен­ной модифицированным поли(1-триметилсилил-1-пропином) (ПТМСП). Поскольку первым способом удалось определить только н-гексан и этилацетат, была разработана и валидирована методика определения четырех остаточных растворителей — дихлорметана, этилацетата, МТБЭ, н-гексана в исследуемой субстанции методом газовой хроматографии на колонке с модифицированной фазой на основе ПТМСП. Обнаружены следовые количества этилацетата и МТБЭ, содержания дихлорметана и н-гексана в субстанции — ниже пределов обнаружения. Средние содержания этилацетата и МТБЭ в субстанции для 9 параллельных определений составили 0,10 и 0,20 ppm, что ниже ПДС (5000 ppm) в 5 и 2,5 • 10⁴ раз соответственно. Проведена оценка разработанной методики по следующим характеристикам: специфичность, линейность градуировочного графика, правильность, прецизионность на уровне повторяемости и внутрилабораторной прецизионности, устойчивость хроматографической системы. Стандартные отклонения результатов при определении этилацетата и МТБЭ в субстанции с использованием разработанной методики не превышают 0,03 и 0,09 соответственно. Методика является специфичной, точной и достоверной для определения остаточных органических раство­рителей в субстанции.

The novel antiparkinsonian agent PA-96 is the focus of our research. PA-96 supported the survival of cultured naïve dopamine neurons, alleviated motor deficits in MPTP and haloperidol-based mice models of Parkinson’s disease, and increased the density of tyrosine hydroxylase positive neurons and dopamine concentration in the midbrain of an MPTP-damaged brain. In this work, an HPLC–MS/MS method was developed and validated, and the pharmacokinetics of the agent was investigated in mice after a single or multiple oral administration (p.o.) and intravenous injection (i.v.) at various doses. The dose proportionality was also evaluated after a single p.o. administration of three ascending doses (1, 5, and 10 mg/kg) and a single i.v. injection of two doses (1 and 10 mg/kg); also, the bioavailability was estimated. The disproportionality of pharmacokinetic parameters could be explained by the saturation of active centres of enzymes or receptors binding the substance: at low doses, part of the compound is bound, leaving a small amount circulating in blood, and rapidly metabolised and/or bound too. The bioavailability of PA-96 was c.a. 7 and 35% for the doses of 5 and 10 mg/kg, correspondingly.

INTRODUCTION. According to the literature, alcoholic extracts of Nonea rossica Steven have anticoagulant, antimicrobial, and antifungal properties, which may be due to the presence of caffeic acid and its derivatives in the plant. The standardisation of this herbal drug requires the development of an analytical procedure for the quantitative determination of caffeic acid, and the most promising method for this is high-performance liquid chromatography (HPLC).AIM. This study aimed to develop and validate an analytical procedure for the quanti­tative determination of caffeic acid in Nonea rossica herb by HPLC.MATERIALS AND METHODS. The study focused on the aerial parts of Nonea rossica plants collected in a steppificated meadow in the Novosibirsk Region during the flowering stage. The study used an Agilent 1100 Series HPLC system equipped with a Zorbax SB-C18 column (150 × 2.1 mm, 3.5 μm) and a detector operating at a wavelength of 330 nm.RESULTS. The authors selected chromatographic conditions to obtain one peak per one molecular form of caffeic acid, an acceptable resolution of the extract components, and the maximum intensity of the analyte peak. The gradient elution conditions developed in this study were as follows: a two-component mobile phase, including a 0.01 M aqueous solution of KH2PO4 with a pH of 2.70 (Solvent A) and methanol (Solvent B), and a flow rate of 0.25 mL/min. Under these conditions, caffeic acid eluted at 13.5 minutes, and the total analysis time was 60 minutes. The analytical procedure was validated for its specificity, analytical range, detection limit, quantitation limit, accuracy, repeatability, and intralaboratory precision.CONCLUSIONS. The developed and validated analytical procedure for the quantita­tive determination of caffeic acid in Nonea rossica herb by HPLC provides results with a relative standard deviation of ≤5.0%. The analytical procedure can be used to standardise the herbal drug Noneae rossicae herba for further use in medicinal practice.