In this paper, fourteen new L-proline derivatives were designed and synthesized, and their acetlcholinesterase (AChE) inhibitory activities were also investigated in vitro. New L-proline derivatives were prepared from substituted 2-bromo-1-acetophenones through four-step reaction; and their bioactivities as AChE inhibitors were measured by Ellman spectrophotometry. The results showed that the target compounds had a certain AChE inhibitory activity to in vitro. The bioactivity of compound 8b was the best of them, and its IC50 value was 5.45 µmol.L-1, which was better than that of rivastigmine. So the acetylcholinesterase inhibitory activities of new L-proline derivatives were worth to be further studied.
Acetylcholinesterase ; Cholinesterase Inhibitors ; chemical synthesis ; chemistry ; Drug Design ; Proline ; analogs & derivatives ; Rivastigmine ; chemistry ; Structure-Activity Relationship

The coronavirus disease 2019 (COVID-19) pandemic has stimulated tremendous efforts to develop therapeutic agents that target severe acute respiratory syndrome coronavirus 2 to control viral infection. So far, a few small-molecule antiviral drugs, including nirmatrelvir-ritonavir (Paxlovid), remdesivir, and molnupiravir have been marketed for the treatment of COVID-19. Nirmatrelvir-ritonavir has been recommended by the World Health Organization as an early treatment for outpatients with mild-to-moderate COVID-19. However, the existing treatment options have limitations, and effective treatment strategies that are cost-effective and convenient for tackling COVID-19 are still needed. To date, four domestically developed oral anti-COVID-19 drugs have been granted conditional market approval in China. These drugs include azvudine, simnotrelvir-ritonavir (Xiannuoxin), leritrelvir, and mindeudesivir (VV116). Preclinical and clinical studies have explored the efficacy and tolerability of mindeudesivir and supported its early use in mild-to-moderate COVID-19 cases at high risk for progression. In this review, we discuss the most recent findings regarding the pharmacological mechanism and therapeutic effects focusing on mindeudesivir and other small-molecule antiviral agents for COVID-19. These findings will expand our understanding and highlight the potential widespread application of China's homegrown anti-COVID-19 drugs.
Humans ; Ritonavir/therapeutic use* ; COVID-19 ; Antiviral Agents/therapeutic use* ; China ; Nitriles ; Lactams ; Proline ; Adenosine/analogs & derivatives* ; Leucine

OBJECTIVE: To investigate the effects of stachydrine (STA) on apoptosis of Aβ-induced PC12 cells mimicking Alzheimer's disease and explore the mechanisms. METHODS: The differential genes of STA were analyzed based on GSE85871 data, and the target genes of STA were identified using STITCH database. PC12 cells were treated with Aβ to establish a cell model of Alzheimer's disease, and the changes in cell viability and cell cycle in response to STA treatment were assessed using MTT assay and flow cytometry, respectively. RT-PCR and Western blotting were used to detect the relevant gene or protein expressions in the treated cells. RESULTS: GSE85871 data showed 37 up-regulated genes and 48 down-regulated genes in cells following treatment with STA. Analysis of the data from the STITCH database indicated that RPS8 and EED were the target genes of STA. Treatment of PC12 cells with Aβ significantly lowered the cell viability ( < 0.05) and the expressions of RPS8 and EED at both the mRNA and protein levels ( < 0.05), and obviously inhibited the expression of apoptosis-related proteins Bcl-2 and p53 ( < 0.05). STA treatment of the cells significantly reversed the effect of Aβ and induced cell cycle arrest in G2/M phase, causing also significantly increases in the expression levels of RPS8, EED, Bcl-2 and p53 ( < 0.05). CONCLUSIONS STA plays an important role in inhibiting the apoptosis of PC12 cells induced by Aβ possibly by regulating RPS8 and EED expression to promote the expressions of Bcl-2 and p53.
Alzheimer Disease ; Animals ; Apoptosis ; drug effects ; Cell Survival ; drug effects ; Gene Expression Regulation ; drug effects ; Models, Biological ; PC12 Cells ; Proline ; analogs & derivatives ; pharmacology ; Rats

OBJECTIVETo observe the changes in the expression of connective tissue growth factor (CTGF), type I collagen (Col I), and type III collagen (Col III) among the rats with acute paraquat (PQ) poisoning and the intervention effect of pyrrolidine dithiocarbamate (PDTC) on their expression, and to investigate the mechanism of PQ-induced pulmonary fibrosis and the intervention effect of PDTC on the disease.

METHODSSprague-Dawley rats were randomly divided into control group (n = 6), PQ group (n = 36), and PQ + PDTC group (n = 36). The PQ group and PQ + PDTC group were given a single dose of saline-diluted PQ (80 mg/kg) by gavage; 2 h later, the PQ + PDTC group was intraperitoneally injected with a single dose of PDTC (100 mg/kg), and the PQ group was intraperitoneally injected with the same amount of saline. The control group was given saline (1 ml/kg) by gavage and was intraperitoneally injected with the same amount of saline 2h later. At 1, 3, 7, 14, 25, and 56 days after operation, the protein expression of CTGF was evaluated by Western blot; the mRNA expression of CTGF, Col I, and Col III was analyzed by real-time quantitative PCR; the content of hydroxyproline in lung tissue was measured, and the pathological changes of lung tissue of the poisoned rats were observed.

RESULTSThe protein expression of CTGF in the PQ group increased as the time went on, slowly from the 3rd to the 14th day and rapidly from the 28th to the 56th day, significantly higher than that in the control group at each time point (P < 0.05 or P < 0.01). The mRNA expression of CTGF in the PQ group began to rise markedly on the 1st day, increased rapidly from the 3rd to the 14th day, and remained at a relatively high level from the 28th to the 56th day, significantly higher than that in the control group at each time point (P < 0.01). The mRNA expression of Col I in the PQ group changed little on the 1st and 3rd day, increased slightly on the 7th day, and increased greatly from the 14th to the 56th day, significantly higher than that in the control group from the 7th to the 56th day (P < 0.05 or P < 0.01). The mRNA expression of Col III in the PQ group began to rise on the 1st day, reached the peak level on the 7th day, and then declined, significantly higher than that in the control group at each time point (P < 0.05 or P < 0.01). Masson staining showed that fibroblasts proliferated from the 14th to the 28th day, and collagen fibers increased gradually. Compared with the PQ group, the PQ + PDTC group showed significantly decreased protein expression of CTGF as well as mRNA expression of CTGF, Col I, and Col III (P < 0.05 or P < 0.01).

CONCLUSIONIn PQ-induced pulmonary fibrosis, the expression of CTGF keeps rising, and the collagen secretion and matrix synthesis are increased probably by upregulating the transcriptional levels of Col I and Col III; CTGF plays an important role in PQ-induced pulmonary fibrosis. PDTC can inhibit the expression of CTGF, thus reducing the lung injury in rats with PQ poisoning.

Animals ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Connective Tissue Growth Factor ; metabolism ; Male ; Paraquat ; poisoning ; Proline ; analogs & derivatives ; pharmacology ; Pulmonary Fibrosis ; chemically induced ; metabolism ; Rats ; Rats, Sprague-Dawley ; Thiocarbamates ; pharmacology

OBJECTIVETo study the function of nuclear factor-kappaB (NF-kappaB) signaling pathway in regulating vascular endothelial growth factor (VEGF) by hepatitis B virus X protein (HBx).

METHODSAfter the establishment of L02-HBx cell line with stable transfected HBx gene, NF-kappaB signaling pathway blocker PDTC was introduced to cut off its signal transduction. Double immunofluorescent staining and laser scanning confocal microscopy were applied to study the activation and deactivation of NF-kappaB signaling pathway. Real-time PCR and Western blot were used to observe the expression of VEGF gene before and after the HBx transfection, as well as the treatment with PDTC.

RESULTSThe NF-kappaB signaling pathway of L02-HBx cells was activated after transfection with HBx gene as compared to the control L02 cells without treatment. The mRNA and protein levels of VEGF in L02-HBx cells increased 4.07 +/- 0.31 and 4.34 +/- 0.64 times respectively. The difference was of statistical significance (P < 0.05) in comparison with the control cells. The mRNA levels of VEGF decreased to 2.33 +/- 0.22 and 1.86 +/- 0.18(P < 0.05) and at the same time the expression of VEGF also reduced to 2.52 +/- 0.29 and 2.17 +/- 0.34 (P < 0.05), after treatment with 25.0 micromol/L and 50.0 micromol/L PDTC for 24 h respectively when the NF-kappaB signaling pathway was blocked. There was no significant difference in VEGF mRNA and protein levels when treated with 12.5 micromol/L PDTC for 24 h.

CONCLUSIONNF-kappaB signaling pathway maybe one of the routes through which HBx up-regulate the expression of VEGF to promote angiogenesis in hepatocellular carcinoma.

Cell Line ; NF-kappa B ; genetics ; metabolism ; Proline ; analogs & derivatives ; pharmacology ; RNA, Messenger ; genetics ; Signal Transduction ; Thiocarbamates ; pharmacology ; Trans-Activators ; genetics ; Transfection ; Vascular Endothelial Growth Factor A ; genetics ; metabolism ; Viral Regulatory and Accessory Proteins ; genetics

AIMTo identify the main metabolites of stachydrine in rat.

METHODSThe ionization, cleavage and chromatographic characteristics of stachydrine were studied by using high-performance liquid chromatography-electrospray ionization ion trap tandem mass spectrometry (HPLC-ESI/MS) for the first time. These characteristics of stachydrine were used as the basis for the analyses of metabolites in rat urine. The 0 - 24 h urine samples of rats after ig 25 mg x kg(-1) stachydrine were collected and purified by using C10 solid-phase extraction cartridge, and then analyzed by HPLC-ESI/MS to identify stachydrine and its metabolites.

RESULTSThe parent drug (stachydrine), 6 phase I metabolites (N-demethyl, dehydrogenation, ring-oxidation) and 2 phase II metabolites (glycine conjugates of 2 ring-oxidation products) were identified existing in rat urine.

CONCLUSIONThe presented method was proved to be sensitive, rapid, high selective and specific for the identification of stachydrine and its metabolites in rat urine.

Animals ; Chromatography, High Pressure Liquid ; methods ; Plant Roots ; chemistry ; Plants, Medicinal ; chemistry ; Proline ; analogs & derivatives ; isolation & purification ; metabolism ; urine ; Rats ; Rats, Wistar ; Sensitivity and Specificity ; Spectrometry, Mass, Electrospray Ionization ; methods ; Stachys ; chemistry

OBJECTIVETo study the effect of DNR on HL-60 cells apoptosis in vitro and the related mechanism.

METHODSThe apoptosis of HL-60 was observed by microscope, flow cytometry (FCM) and DNA electrophoresis and various apoptosis-associated proteins expression by immunocytochemistry (IC) and FCM assays; the changes of apoptosis in HL-60 cells treated with DNR or suppressors PDTC or FB1 were also observed.

RESULTSWhen treated with 0.2 approximately 2.0 micro mol/L DNR, the percentage of apoptotic HL-60 cells increased with the dose increasing and the time extending, and the typical apoptotic cells and the appearance of apoptotic DNA ladder were observed. It was shown that after treatment with 1 micro mol/L DNR, the fluorescence intensity index (FI) of both bcl-2 and c-myc in HL-60 cells decreased, the FI of Bax, caspase-3 increased at 2 h, but decreased at 5 h, the FI of NF-kappaB increased. After adding PDTC, the apoptosis percentage of HL-60 cells decreased, but FB1 didn't present these effect.

CONCLUSIONIt suggested from the results that at certain concentration, DNR can induce the apoptosis of HL-60 cells in vitro. The mechanism was supposed by suppressing the expression of bcl-2 and c-myc and activating the expression of Bax and caspase-3, NF-kappaB and ROS had the marked correlation with the apoptosis process, but the ceramide synthase wasn't associated with it.

Apoptosis ; drug effects ; Caspase 3 ; Caspases ; analysis ; Ceramides ; biosynthesis ; Daunorubicin ; pharmacology ; Dose-Response Relationship, Drug ; HL-60 Cells ; Humans ; Immunohistochemistry ; NF-kappa B ; analysis ; Proline ; analogs & derivatives ; pharmacology ; Proto-Oncogene Proteins c-myc ; analysis ; Reactive Oxygen Species ; Thiocarbamates ; pharmacology

OBJECTIVETo investigate the relationship between activation of nuclear factor-kappa gene binding (NF-kappaB) and apoptosis induced by matrine in hepatocellular carcinoma cell line HepG2.

METHODSHepG2 cells were stimulated by different concentrations of matrine (0.8, 1.0, 1.5, 2.0, 2.5 g/L). The HepG2 cell survival rates were evaluated by MTT assay. Cultured HepG2 cells were implanted in culture flasks and divided into four groups: a control group, a pyrrolidine dithiocarbamate (PDTC) group (20 micromol/L), a matrine group (1.5 g/L) and a combination group, PDTC (20 micromol/L) + matrine (1.5 g/L) combination group. Apoptosis induced by matrine was analyzed by flow cytometry (FCM) and TUNEL. The DNA-binding activity of NF-kappaB was determined by electrophoretic mobility shift assay (EMSA).

RESULTSPDTC enhanced the inhibition of matrine on cell proliferation (F=183.92, P less than 0.01). The apoptosis and activation of NF-kappaB of HepG2 cells were induced by matrine. PDTC significantly suppressed NF-kappaB activation induced by matrine in HepG2 cells. PDTC increased the apoptosis induced by matrine of the HepG2 cells from 6.11% +/- 0.81% to 12.95% +/- 0.02%, chi2=9.67, P less than 0.01.

CONCLUSIONSMatrine could induce apoptosis, and at the same time induce activation of NF-kappaB in HepG2 cells. PDTC increases the apoptosis in hepatocellular carcinoma cells and it may be related to suppressing NF-kB activation of HepG2 cells.

Alkaloids ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; pathology ; Drug Synergism ; Hep G2 Cells ; Humans ; Liver Neoplasms ; pathology ; NF-kappa B ; metabolism ; Proline ; analogs & derivatives ; pharmacology ; Quinolizines ; pharmacology ; Thiocarbamates ; pharmacology

Even though chemistry is now in place that potentially allows high coupling efficiencies to be attained, successful coupling is usually a challenge when so-called "difficult sequences" is encountered in peptide synthesis. Some factors that affect the coupling efficiency have been discussed and related methods to overcome those obstacles have been introduced in present review. All suggestions proposed here are valuable and also feasible to improve the coupling completeness in both liquid-phase or solid-phase
Acylation ; Amino Acid Sequence ; Molecular Structure ; Organophosphorus Compounds ; chemistry ; Peptide Fragments ; chemical synthesis ; chemistry ; Peptides ; chemical synthesis ; chemistry ; Proline ; analogs & derivatives ; chemistry ; Resins, Synthetic ; chemistry ; Temperature ; Thiazoles ; chemistry ; Thiocyanates ; chemistry ; Triazoles ; chemistry

The quality and grade of traditional Chinese medicinal herbs were assessed by their characteristics traditionally. According to traditional experience, the quality of the purple Flos Farfarae is better than that of yellow buds. NMR-based metabolomic approach combined with significant analysis of microarray (SAM) and Spearman rank correlation analysis were used to investigate the different metabolites of the Flos Farfarae with different color feature. Principal component analysis (PCA) showed clear distinction between the purple and yellow flower buds of Tussilago farfara. The S-plot of orthogonal PLS-DA (OPLS-DA) and t test revealed that the levels of threonine, proline, phosphatidylcholine, creatinine, 4, 5-dicaffeoylquinic acid, rutin, caffeic acid, kaempferol analogues, and tussilagone were higher in the purple flower buds than that in the yellow buds, in agreement with the results of SAM and Spearman rank correlation analysis. The results confirmed the traditional medication experience that "purple flower bud is better than the yellow ones", and provide a scientific basis for assessing the quality of Flos Farfarae by the color features.
Caffeic Acids ; analysis ; Color ; Creatinine ; analysis ; Flowers ; chemistry ; Kaempferols ; analysis ; Magnetic Resonance Spectroscopy ; Metabolomics ; Phosphatidylcholines ; analysis ; Plants, Medicinal ; chemistry ; Principal Component Analysis ; Proline ; analysis ; Quinic Acid ; analogs & derivatives ; analysis ; Rutin ; analysis ; Sesquiterpenes ; analysis ; Threonine ; analysis ; Tussilago ; chemistry