Clinically Applicable AI System for Accurate Diagnosis, Quantitative Measurements, and Prognosis of COVID-19 Pneumonia Using Computed Tomography.

Many COVID-19 patients infected by SARS-CoV-2 virus develop pneumonia (called novel coronavirus pneumonia, NCP) and rapidly progress to respiratory failure. However, rapid diagnosis and identification of high-risk patients for early intervention are challenging. Using a large computed tomography (CT) database from 3,777 patients, we developed an AI system that can diagnose NCP and differentiate it from other common pneumonia and normal controls. The AI system can assist radiologists and physicians in performing a quick diagnosis especially when the health system is overloaded. Significantly, our AI system identified important clinical markers that correlated with the NCP lesion properties. Together with the clinical data, our AI system was able to provide accurate clinical prognosis that can aid clinicians to consider appropriate early clinical management and allocate resources appropriately. We have made this AI system available globally to assist the clinicians to combat COVID-19.

Gamma-aminobutyric acid (GABA) improves salinity stress tolerance in soybean seedlings by modulating their mineral nutrition, osmolyte contents, and ascorbate-glutathione cycle.

BACKGROUND: In plants, GABA plays a critical role in regulating salinity stress tolerance. However, the response of soybean seedlings (Glycine max L.) to exogenous gamma-aminobutyric acid (GABA) under saline stress conditions has not been fully elucidated. RESULTS: This study investigated the effects of exogenous GABA (2 mM) on plant biomass and the physiological mechanism through which soybean plants are affected by saline stress conditions (0, 40, and 80 mM of NaCl and Na2SO4 at a 1:1 molar ratio). We noticed that increased salinity stress negatively impacted the growth and metabolism of soybean seedlings, compared to control. The root-stem-leaf biomass (27- and 33%, 20- and 58%, and 25- and 59% under 40- and 80 mM stress, respectively]) and the concentration of chlorophyll a and chlorophyll b significantly decreased. Moreover, the carotenoid content increased significantly (by 35%) following treatment with 40 mM stress. The results exhibited significant increase in the concentration of hydrogen peroxide (H2O2), malondialdehyde (MDA), dehydroascorbic acid (DHA) oxidized glutathione (GSSG), Na+, and Cl- under 40- and 80 mM stress levels, respectively. However, the concentration of mineral nutrients, soluble proteins, and soluble sugars reduced significantly under both salinity stress levels. In contrast, the proline and glycine betaine concentrations increased compared with those in the control group. Moreover, the enzymatic activities of ascorbate peroxidase, monodehydroascorbate reductase, glutathione reductase, and glutathione peroxidase decreased significantly, while those of superoxide dismutase, catalase, peroxidase, and dehydroascorbate reductase increased following saline stress, indicating the overall sensitivity of the ascorbate-glutathione cycle (AsA-GSH). However, exogenous GABA decreased Na+, Cl-, H2O2, and MDA concentration but enhanced photosynthetic pigments, mineral nutrients (K+, K+/Na+ ratio, Zn2+, Fe2+, Mg2+, and Ca2+); osmolytes (proline, glycine betaine, soluble sugar, and soluble protein); enzymatic antioxidant activities; and AsA-GSH pools, thus reducing salinity-associated stress damage and resulting in improved growth and biomass. The positive impact of exogenously applied GABA on soybean plants could be attributed to its ability to improve their physiological stress response mechanisms and reduce harmful substances. CONCLUSION: Applying GABA to soybean plants could be an effective strategy for mitigating salinity stress. In the future, molecular studies may contribute to a better understanding of the mechanisms by which GABA regulates salt tolerance in soybeans.

Myeloid gasdermin D drives early-stage T cell immunity and peripheral inflammation in a mouse model of Alzheimer's disease.

BACKGROUND: It is now realized that peripheral inflammation and abnormal immune responses, especially T cells, contribute to the development of Alzheimer's disease (AD). Gasdermin D (GSDMD) -mediated pyroptosis has been associated with several neuroinflammatory diseases, but whether GSDMD is involved in the peripheral inflammation and T cell immunity during AD remains unclear. METHODS: We dynamically investigated GSDMD activation in the peripheral and central nervous system of 5×FAD mouse model and dissected the role of myeloid GSDMD using genetic knockout mice, especially its influence on peripheral T cell responses and AD inflammation. RNA sequencing and in vitro coculture were used to elucidate the underlying immune mechanisms involved. Targeted inhibitor experiments and clinical correlation analysis were used to further verify the function of GSDMD in AD. RESULTS: In the present study, caspase activated GSDMD in the spleen of 5×FAD mice earlier than in the brain during disease progression. Loss of myeloid cell GSDMD was shown to impair early-stage effector T cell activation in the periphery and prevent T cell infiltration into the brain, with an overall reduction in neuroinflammation. Furthermore, myeloid cell GSDMD induced T cell PD-1 expression through the IL-1ß/NF-κB pathway, restricting regulatory T cells. The administration of a GSDMD inhibitor combined with an anti-PD-1 antibody was found to mitigate the development of AD-associated inflammation. In some AD patients, plasma sPD-1 is positively correlated with IL-Iß and clinical features. CONCLUSIONS: Our study systematically identified a role for GSDMD in the AD-related peripheral inflammation and early-stage T cell immunity. These findings also suggest the therapeutic potential of targeting GSDMD for the early intervention in AD.

Unlocking the potential of the 3-hydroxykynurenine/kynurenic acid ratio: a promising biomarker in adolescent major depressive disorder.

Metabolites disruptions in tryptophan (TRP) and kynurenine pathway (KP) are believed to disturb neurotransmitter homeostasis and contribute to depressive symptoms. This study aims to investigate serum levels of KP metabolites in adolescent major depressive disorder (AMDD), and examine their relationship with depression severities. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to analyze serum levels of TRP, kynurenic acid (KYNA), kynurenine (KYN), and 3-hydroxy-kynurenine (3-HK) in 143 AMDD participants and 98 healthy controls (HC). Clinical data, including Children's Depression Inventory (CDI) scores, were collected and analyzed using statistical methods, such as ANOVA, logistic regression, Receiver operating characteristic curve analysis and a significance level of p < 0.05 was used for all analyses. AMDD showed significantly decreased serum levels of KYNA (-25.5%), KYN (-14.2%), TRP (-11.0%) and the KYNA/KYN ratio (-11.9%) compared to HC (p < 0.01). Conversely, significant increases were observed in 3-HK levels (+50.4%), the 3-HK/KYNA ratio (+104.3%) and the 3-HK/KYN ratio (+93.0%) (p < 0.01). Logistic regression analysis identified increased level of 3-HK as a contributing factor to AMDD, while increased level of KYNA acted as a protective factor against AMDD. The 3-HK/KYNA ratio demonstrated an area under the curve (AUC) of 0.952. This study didn't explore AMDD's inflammatory status and its metabolites relationship explicitly. These findings indicate that metabolites of TRP and KP may play a crucial role in the pathogenesis of AMDD, emphasizing the potential of the 3-HK/KYNA ratio as a laboratory biomarker for early detection and diagnosis of AMDD.

Preparation of mesoporous silica nanocarriers targeting glucose-6-phosphate isomerase inhibition and application in the treatment of rheumatoid arthritis.

Glucose 6-phosphate isomerase (G6PI) is an indicator to assist in diagnosis of rheumatoid arthritis (RA) and monitor the disease. It also plays a key role in proliferating RA synovial tissues, pannus formation, and invasion and destruction of articular cartilage. In this study, we synthesized nanoparticles targeting G6PI (siG6PI-MSN) using mesoporous silica nanocarriers (MSN) and small interfering RNA (siRNA), followed by identifying the characteristics and functions, and preliminarily exploring their application in the treatment of RA in vivo with a type II collagen-induced arthritis (CIA) rat model. It showed that the synthetic functionalized carrier had a regular pore structure and a specific volume and surface area. No obvious hemolysis or toxicity of the carrier was found when its concentration was below 100 µg/ml. Cytological results in vitro suggested that siG6PI-MSN significantly inhibited G6PI expression and reduced the ability of proliferation, migration, and invasion of FLSs, compared with the siNC-MSN group. In vivo results in the CIA rat model showed that the arthritis index and degree of joint swelling among rats in the siG6PI-MSN-treatment group were significantly lower than those in the control group. Moreover, the number of FLSs in Synovium and the levels of TNF α and IL-1 ß were also significantly decreased in the siG6PI-MSN group. Histopathology of the synovial tissue and cartilage revealed siG6PI-MSN treatment significantly reduced the pathological manifestations of arthritis. In conclusion, siG6PI-MSN effectively suppresses the proliferation and invasive growth of synovial tissue and improve joint swelling and inflammatory infiltration, thereby preventing joint damage in RA. This carrier may be a new therapeutic measure for RA, with potential social and economic benefits.

Inhibition of hexokinase 2 with 3-BrPA promotes MDSCs differentiation and immunosuppressive function.

The adoptive transfer of ex vivo generated myeloid-derived suppressor cells (MDSCs) may be a promising therapeutic strategy for preventing allograft rejection after solid organ transplantation. Currently, the precise role of immune-metabolic pathways in the differentiation and function of MDSCs is not fully understood. Hexokinase 2 (HK2) is an isoform of hexokinase and is a key enzyme involved in the increased aerobic glycolysis of different immune cells during their activation and function. Here, we demonstrate that the addition of HK2 inhibitor 3-Bromopyruvic acid (3-BrPA) into traditional MDSCs induction system in vitro significantly promoted MDSCs production and enhanced their immunosuppressive function. Treatment with 3-BrPA increased the expression of MDSC-related immunosuppressive molecules, such as iNOS, Arg1, and CXCR2. Moreover, the adoptive transfer of 3-BrPA-treated MDSCs significantly prolonged the survival time of mouse heart allografts. This study provides a novel strategy to solve the problems of harvesting enough autologous cells for MDSC production from sick patients, and producing functionally enhanced MDSCs for preventing graft rejection and inducing tolerance.

Theoretical growth rate of microalgae under high/low-flashing light.

Dynamic light regimes strongly impact microalgal photosynthesis efficiency. Finding the optimal way to supply light is then a tricky problem, especially when the growth rate is inhibited by overexposition to light and, at the same time, there is a lack of light in the deepest part of the culture. In this paper, we use the Han model to study the theoretical microalgal growth rate by applying periodically two different light intensities. Two approaches are considered depending on the period of the light pattern. For a large light period, we demonstrate that the average photosynthetic rate can be improved under some conditions. Moreover, we can also enhance the growth rate at steady state as given by the PI-curve. Although, these conditions change through the depth of a bioreactor. This theoretical improvement in the range of 10-15% is due to a recovery of photoinhibited cells during the high irradiance phase. We give a minimal value of the duty cycle for which the optimal irradiance is perceived by the algae culture under flashing light regime.

Near-Field Modulation of Differently Oriented Single Photon Emitters with A Plasmonic Probe.

Single photon emitters (SPEs) are critical components of photon-based quantum technology. Recently, the interaction between surface plasmons and emitters has attracted increasing attention because of its potential to improve the quality of single-photon sources through stronger light-matter interactions. In this work, we use a hybrid plasmonic probe composed of a fiber taper and silver nanowire to controllably modulate the radiation properties of SPEs with differently oriented polarization. For out-of-plane oriented SPEs such as single CdSe quantum dots, the radiation lifetime could be reduced by a factor as large as seven; for in-plane oriented SPEs such as hBN defect SPEs, the average modulation amplitude varied from 0.69 to 1.23, depending on the position of the probe. The experimental results were highly consistent with the simulations and theory. This work provides an efficient approach for optimizing the properties of SPEs for quantum photonic integration.

Dynamically controlled nanofocusing metalens based on graphene-loaded aperiodic silica grating arrays.

A new plasmonic nanofocusing metalens based on aperiodic silica grating arrays was designed and investigated. Assisted by the graphene surface plasmon, the infrared polarized light can be focused in a nanospot with a dynamically controlled focal length by varying the dielectric strip width or the graphene Fermi level Ef. For instance, with λ0 = 8 µm and Ef at 0.3, 0.6 and 0.9 eV, focal lengths of 4.5, 3.8 and 3.5 µm with its corresponding FWHM of 64, 232 and 320 nm, respectively, can be realized. The variation of the focusing efficiency with respect to the incident wavelength and the Fermi level were also investigated. The results of theoretical analysis based on light differential equations agree well with the finite element analysis simulation, which further validate the model.

CFTR Suppresses Neointimal Formation Through Attenuating Proliferation and Migration of Aortic Smooth Muscle Cells.

ABSTRACT: Cystic fibrosis transmembrane conductance regulator (CFTR) plays important roles in arterial functions and the fate of cells. To further understand its function in vascular remodeling, we examined whether CFTR directly regulates platelet-derived growth factor-BB (PDGF-BB)-stimulated vascular smooth muscle cells (VSMCs) proliferation and migration, as well as the balloon injury-induced neointimal formation. The CFTR adenoviral gene delivery was used to evaluate the effects of CFTR on neointimal formation in a rat model of carotid artery balloon injury. The roles of CFTR in PDGF-BB-stimulated VSMC proliferation and migration were detected by mitochondrial tetrazolium assay, wound healing assay, transwell chamber method, western blot, and qPCR. We found that CFTR expression was declined in injured rat carotid arteries, while adenoviral overexpression of CFTR in vivo attenuated neointimal formation in carotid arteries. CFTR overexpression inhibited PDGF-BB-induced VSMC proliferation and migration, whereas CFTR silencing caused the opposite results. Mechanistically, CFTR suppressed the phosphorylation of PDGF receptor ß, serum and glucocorticoid-inducible kinase 1, JNK, p38 and ERK induced by PDGF-BB, and the increased mRNA expression of matrix metalloproteinase-9 and MMP2 induced by PDGF-BB. In conclusion, our results indicated that CFTR may attenuate neointimal formation by suppressing PDGF-BB-induced activation of serum and glucocorticoid-inducible kinase 1 and the JNK/p38/ERK signaling pathway.

The influence of single layer MoS2flake on the propagated surface plasmons of silver nanowire.

We demonstrate enhancing the excitation and transmission efficiency of the propagated surface plasmon (SP) of an Ag nanowire (Ag NW) in hybrid Ag-MoS2structures by contrasting the SP propagation of the Ag NW on different substrates, including SiO2and monolayer MoS2, or partially overlapping the Ag NW on MoS2flakes. The simulation results show that the leaky radiation of the hybrid plasmonic modes H1and H2can be prominently suppressed due to the high refractive index dielectric layer of MoS2, which provides an optical barrier for blocking the leaky radiation, resulting in reduced propagation loss. This paper provides a feasible and effective method to improve the SP propagation length.

Combined strategy of knowledge-based rule selection and historical data percentile-based range determination to improve an autoverification system for clinical chemistry test results.

BACKGROUND: Current autoverification, which is only knowledge-based, has low efficiency. Regular historical data analysis may improve autoverification range determination. We attempted to enhance autoverification by selecting autoverification rules by knowledge and ranges from historical data. This new system was compared with the original knowledge-based system. METHODS: New types of rules, extreme values, and consistency checks were added and the autoverification workflow was rearranged to construct a framework. Criteria for creating rules for extreme value ranges, limit checks, consistency checks, and delta checks were determined by analyzing historical Zhongshan laboratory data. The new system's effectiveness was evaluated using pooled data from 20 centers. Efficiency improvement was assessed by a multicenter process. RESULTS: Effectiveness was evaluated by the true positive rate, true negative rate, and overall consistency rate, as compared to manual verification, which were 77.55%, 78.53%, and 78.3%, respectively for the new system. The original overall consistency rate was 56.2%. The new pass rates, indicating efficiency, were increased by 19%-51% among hospitals. Further customization using individualized data increased this rate. CONCLUSIONS: The improved system showed a comparable effectiveness and markedly increased efficiency. This transferable system could be further improved and popularized by utilizing historical data from each hospital.

Silencing of CYP6AS160 in Solenopsis invicta Buren by RNA interference enhances worker susceptibility to fipronil.

Cytochrome P450 monooxygenases play a key role in pest resistance to insecticides by detoxification. Four new P450 genes, CYP6AS160, CYP6AS161, CYP4AB73 and CYP4G232 were identified from Solenopsis invicta. CYP6AS160 was highly expressed in the abdomen and its expression could be induced significantly with exposure to fipronil, whereas CYP4AB73 was not highly expressed in the abdomen and its expression could not be significantly induced following exposure to fipronil. Expression levels of CYP6AS160 and CYP4AB73 in workers were significantly higher than that in queens. RNA interference-mediated gene silencing by feeding on double-stranded RNA (dsRNA) found that the levels of this transcript decreased (by maximum to 64.6%) when they fed on CYP6AS160-specific dsRNA. Workers fed dsCYP6AS160 had significantly higher mortality after 24 h of exposure to fipronil compared to controls. Workers fed dsCYP6AS160 had reduced total P450 activity of microsomal preparations toward model substrates p-nitroanisole. However, the knockdown of a non-overexpressed P450 gene, CYP4AB73 did not lead to an increase of mortality or a decrease of total P450 activity. The knockdown effects of CYP6AS160 on worker susceptibility to fipronil, combined with our other findings, indicate that CYP6AS160 is responsible for detoxification of fipronil. Feeding insects dsRNA may be a general strategy to trigger RNA interference and may find applications in entomological research and in the control of insect pests in the field.

CYP4CJ6-mediated resistance to two neonicotinoid insecticides in Sitobion miscanthi (Takahashi).

The wheat aphid Sitobion miscanthi (CWA) is an important harmful pest in wheat fields. Insecticide application is the main method to effectively control wheat aphids. However, CWA has developed resistance to some insecticides due to its extensive application, and understanding resistance mechanisms is crucial for the management of CWA. In our study, a new P450 gene, CYP4CJ6, was identified from CWA and showed a positive response to imidacloprid and thiamethoxam. Transcription of CYP4CJ6 was significantly induced by both imidacloprid and thiamethoxam, and overexpression of CYP4CJ6 in the imidacloprid-resistant strain was also observed. The sensitivity of CWA to these two insecticides was increased after the knockdown of CYP4CJ6. These results indicated that CYP4CJ6 could be associated with CWA resistance to imidacloprid and thiamethoxam. Subsequently, the posttranscriptional regulatory mechanism was assessed, and miR-316 was confirmed to participate in the posttranscriptional regulation of CYP4CJ6. These results are crucial for clarifying the roles of P450 in the resistance of CWA to insecticides.

Associations of long-term physical activity trajectories with coronary artery calcium progression and cardiovascular disease events: results from the CARDIA study.

OBJECTIVE: The study aimed to assess the associations of physical activity (PA) trajectories across a 25-year span with coronary artery calcium (CAC) progression, and subsequent risk of cardiovascular disease (CVD) events. METHODS: We included 2497 participants from the Coronary Artery Disease Risk Development in Young Adults study who had computed tomography-assessment of CAC at baseline (year 15: 2000-2001) and follow-up (year 20 or 25) and at least three measures of PA from year 0 to year 25. Long-term PA trajectories were determined by latent class modelling using a validated questionnaire. RESULTS: Among the included participants, 1120 (44.9%) were men, 1418 (56.8%) were white, and the mean (SD) age was 40.4 (3.6) years. We identified three distinct PA trajectories based on PA average levels and change patterns: low (below PA guidelines, n=1332; 53.3%); moderate (meeting and slightly over PA guidelines, n=919; 36.8%) and high (about three times PA guidelines or more, n=246; 9.9%). During a mean (SD) follow-up of 8.9 (2.1) years, 640 (25.6%) participants had CAC progression. Participants in the high PA trajectory group had a higher risk of CAC progression than those in the low PA trajectory group after adjustment for traditional cardiovascular risk factors (HR 1.51; 95% CI 1.18 to 1.94). However, high PA trajectory was not associated with an increased risk of incident CVD events (HR 1.01; 95% CI 0.44 to 2.31) and the incidence of CVD events in participants with CAC progression was similar across all three PA trajectory groups (p=0.736). CONCLUSION: Long-term PA about three times the guidelines or more is independently associated with CAC progression; however, no additional risk of incident CVD events could be detected.

Free fatty acids and triglyceride change in the gallbladder bile of gallstone patients with pancreaticobiliary reflux.

BACKGROUND: Pancreaticobiliary reflux (PBR) causes chronic inflammation of the gallbladder mucosa and changes in the bile components, which are known to promote gallstone formation. This study aimed to investigate the bile biochemistry changes in gallstone patients with PBR and provide new clues for research on the involvement of PBR in gallstone formation. METHODS: Patients undergoing surgery for gallstones between December 2020 and May 2021 were eligible for inclusion. The bile biochemistry (including amylase, lipase, triglyceride, cholesterol, free fatty acids [FFAs], alanine aminotransferase [ALT], aspartate aminotransferase [AST], alkaline phosphatase [ALP], and γ-glutamyl transferase [γ-GT]) of the included gallstone patients was analysed to determine correlations with PBR. RESULTS: In this study, 144 gallstone patients who underwent surgery were enrolled. Overall, 15.97 % of the patients had an increased bile amylase level, which was associated with older age and significantly higher bile levels of ALP, lipase, triglyceride, and FFAs. Positive correlations were observed between amylase and lipase, triglyceride, FFAs levels in the gallbladder bile. However, the bile levels of triglyceride, FFAs, and lipase were positively correlated with each other only in the PBR group and showed no significant correlation in the control (N) group. In addition, elevated bile FFAs levels were found to be an independent risk factor for gallbladder wall thickening. CONCLUSIONS: In conclusion, PBR-induced increase in FFAs and triglyceride in the gallbladder bile is a cause of gallstone formation, and an increase in bile ALP suggests the presence of cholestasis in PBR.

Identification of differentially expressed microRNAs under imidacloprid exposure in Sitobion miscanthi.

Imidacloprid is a neonicotinoid that targets sucking pests, such as aphids and the green leaf bug and has been widely applied in wheat fields to control wheat aphids in China. To investigate the involvement of miRNAs in imidacloprid resistance, we sequenced small RNA libraries of Sitobion miscanthi Fabricius, across two different treatments using Illumina short-read sequencing technology. As a result, 265 microRNAs (miRNAs), of which 242 were known and 23 were novel, were identified. Quantitative analysis of miRNA levels showed that 23 miRNAs were significantly up-regulated, and 54 miRNAs were significantly down-regulated in the nymphs of S. miscanthi treated with imidacloprid in comparison with those of the control. Modulation of the abundances of differentially expressed miRNAs, smi-miR-316, smi-miR-1000, and smi-miR-iab-4 by the addition of the corresponding antagomir/inhibitor to the artificial diet significantly changed the susceptibility of S. miscanthi to imidacloprid. Subsequently, the post-transcriptional regulatory mechanism was conducted, smi-miR-278 and smi-miR-316 were confirmed to be participated in the post-transcriptional regulation of nAChRα1A and CYP4CJ6, respectively. The results suggested that miRNAs differentially expressed in response to imidacloprid could play a critical regulatory role in the metabolism of S. miscanthi to imidacloprid.

Quercetin inhibits proliferation of and induces apoptosis in non-small-cell lung carcinoma via the lncRNA SNHG7/miR-34a-5p pathway.

OBJECTIVE: To determine the role of quercetin in non-small cell lung carcinoma (NSCLC) and the biological outcomes using transfection experiments. MATERIALS AND METHODS: Real-time reverse transcription-PCR and data collection were performed to determine lncRNA and miRNA levels. Transwell assay was performed to assess the invasion ability of cells. Apoptosis of cells digested with trypsin was determined using the Annexin V-FITC kit. Luciferase activity was determined using the luciferase reporter gene system. Cell viability was tested using the Cell Counting Kit-8 assay. A xenograft mouse model was established to investigate the effects of quercetin on tumor growth. RESULTS: The expression levels of the long non-coding RNA (lncRNA) small nucleolar RNA host gene 7 (SNHG7) were elevated in NSCLC cells, and the expression levels of the microRNA miR-34a-5p were decreased compared with those in normal cells. Further investigation revealed that quercetin decreased SNHG7 and elevated miR-34a-5p levels in NSCLC cells (p < .05). The luciferase reporter gene assay, RNA-binding protein immunoprecipitation assay, and transfection experiments revealed target-binding sequences between SNHG7 and miR-34a-5p. Overexpression of SNHG7 or miR-34a-5p inhibitor promoted NSCLC cell proliferation and accelerated tumor cell growth and metastasis. The therapeutic effect of quercetin on NSCLC cells was counteracted by co-transfection of SNHG7 mimic or miR-34a-5p inhibitor. Quercetin inhibited the survival, proliferation, migration, and invasion of NSCLC cells and enhanced their apoptosis. Using the mouse model, quercetin was shown to inhibit tumor growth. CONCLUSIONS: Quercetin inhibits the proliferation and induces apoptosis of NSCLC cells by mediating signaling via the lncRNA SNHG7/miR-34a-5p pathway.

Synthesis of chrysin derivatives and screening of antitumor activity.

A series of aromatic or long-chain chrysin derivatives (1-10) were synthesized by esterification of chrysin and acyl chloride. The chemical structures of these compounds were determined by mass spectrum (MS), 1H NMR, and 13C NMR spectra. Though aromatic chrysin derivatives (1-9) with a rigid structure were hard to dissolve in common organic solvents, the long-chain chrysin derivative (10) with a flexible structure had better solubility, and its anticancer activity (IC50 = 14.79 µmol/L) against liver cancer cell lines was 5.4 times better than chrysin (IC50 = 74.97 µmol/L), which showed superposition of pharmacological activity.