The composition of lipophilic components of sea buckthorn leafy shoots, a large tonnage waste in the production of sea buckthorn oil and during renewing the cultural plantings of sea buckthorn, was...

Currently, SARS-CoV-2 spike receptor-binding-domain (RBD)-based vaccines are considered one of the most effective weapons against COVID-19. During the first step of assessing vaccine immunogenicity, a mouse model is often used. In this paper, we tested the use of five experimental animals (mice, hamsters, rabbits, ferrets, and chickens) for RBD immunogenicity assessments. The humoral immune response was evaluated by ELISA and virus-neutralization assays. The data obtained show hamsters to be the least suitable candidates for RBD immunogenicity testing and, hence, assessing the protective efficacy of RBD-based vaccines.

Identification of factors behind the level and duration of persistence of the SARS-CoV-2 antibodies in the blood is assumed to set the direction for studying humoral immunity mechanisms against COVID-19, optimizing the strategy for vaccine use, antibody-based drugs, and epidemiological control of COVID-19. Objective: This study aimed to study the relationship between clinical and demographic characteristics and the level of IgG antibodies to the RBD of SARS-CoV-2 spike protein after COVID-19 in the long term. Residents of the Altai Region of Western Siberia of Russia, Caucasians, aged from 27 to 93 years (median 53.0 years), who recovered from COVID-19 between May 2020 and February 2021 (n = 44) took part in this prospective observational study. The titer of IgG antibodies to the RBD of SARS-CoV-2 spike protein was measured repeatedly in the blood at 4–13 months from the beginning of the clinical manifestation of COVID-19 via the method of enzyme-linked immunosorbent assay. The antibody titer positively correlated with age (p = 0.013) and COVID-19 pneumonia (p = 0.002) at 20–40 and 20–24 weeks from the onset of COVID-19 symptoms, respectively. Age was positively associated with antibody titer regardless of history of COVID-19 pneumonia (beta regression coefficient p = 0.009). The antibody titer decreased in 15 (34.1%) patients, increased in 10 (22.7%) patients, and did not change in 19 (43.2%) patients from the baseline to 48–49 weeks from the onset of COVID-19 symptoms, with seropositivity persisting in all patients. Age and COVID-19 pneumonia are possibly associated with higher IgG antibodies to the spike protein RBD of SARS-CoV-2 following COVID-19 in the long term. Divergent trends of anti-RBD IgG levels in adults illustrate inter-individual differences at 4–13 months from the onset of COVID-19 symptoms.

Изучен состав липофильных компонентов облиствленных побегов облепихи – крупнотоннажного отхода при производстве облепихового масла и при омолаживающих рубках культурных насаждений облепихи. В качестве экстрагента сырья использован гексан, обеспечивающий высокую степень извлечения липофильных компонентов и являющийся аналогом экстракционного бензина, применяющегося в пищевой и парфюмерной промышленности. Методами хроматомасс-спектрометрии и высокоэффективной жидкостной хроматографии исследован химический состав гексанового экстракта облиствленных побегов облепихи. Идентифицированы 67 нейтральных и 29 кислых компонентов, в том числе полипренолы, долихолы, тритерпеновые спирты и кислоты, стерины. Основной компонент стериновой фракции – β-ситостерин. Его содержание – 6,9% от массы экстракта, что значительно выше, чем в эфирных экстрактах листьев и жома плодов облепихи. В экстракте он обнаружен преимущественно в свободном виде. В кислой фракции наряду с мажорными алифатическими кислотами содержатся высокоактивные тритерпеновые кислоты (до 5% массы экстракта). Во фракции полипренолов и долихолов (до 4,2%) преобладают компоненты с длиной цепи 11 и 17 изопреновых единиц. Полученные результаты позволяют считать облиственные побеги облепихи перспективным источником биологически активных соединений.

Current strategy for the blockade of molecules inhibiting T-cell immunity, the immune checkpoints (ICP), such as CTLA-4, PD-1, and B7-H1(PD-L1), using monoclonal antibodies (mAbs), showed significant...

The composition of the lipophilic components of Centaurea scabiosa L. has been studied. The raw material was subjected to extraction with hexane and methyl tert-butyl ether (MTBE) using both exhaustive and sequential schemes for a detailed characterization. The resulting extracts were fractionated into acidic and neutral components via treatment with alkali solutions. The acidic compounds were converted into methyl esters for subsequent gas chromatography–mass spectrometry (GC-MS) analysis, while the neutral unsaponifiable fractions were separated into groups of different polarities using column chromatography on silica gel. This approach enabled the identification of a complex profile of lipophilic substances. In the acidic fractions, aliphatic acids with chain lengths from C₁₀ to C₃₂, including unsaturated variants, were characterized. The neutral fractions revealed over compounds, encompassing n-alkanes, substantial levels of the unsaturated branched hydrocarbon squalene, and a diverse array of oxygenated terpenoids. The latter were mainly represented by highly active triterpene alcohols and ketones belonging to the ursane, oleanane, lupane, and cycloartane types. The sterol composition was dominated by β-sitosterol and accompanied by cholesterol, campesterol, stigmasterol, stigmast-7-en-3-β-ol, fucosterol, and stigmastan-3-β-ol. Bioactivity screening demonstrated that several of the obtained lipophilic extracts, particularly those of lower polarity, exhibited high inhibitory activity against the main protease of SARS-CoV-2, underscoring the potential of C. scabiosa as a valuable source of anti-coronavirus agents.