Design, synthesis and triglyceride-lowering activity of tricyclic matrine derivatives for the intervention of non-alcoholic fatty liver disease.

Thirty new tricyclicmatrinic derivatives were successively synthesized and evaluated for their inhibitory activity on the accumulation of triglycerides (TG) in AML12 cells, using 12 N-m-trifluoromethylbenzenesulfonyl matrine (1) as the hit compound. Among the analogues, compound 7n possessing 11-trimethylbutylamine quaternary exerted the highest in vitro TG-lowering potency, as well as a good safety profile. 7n significantly attenuated the hepatic injury and steatosis, and ameliorated dyslipidemia and dysglycemia in the mice with non-alcoholic fatty liver disease (NAFLD) induced by a high-fat diet. Primary mechanism study revealed that upregulation of peroxisome proliferator-activated receptors α (PPARα)-carnitine palmitoyltransferase 1A (CPT1A) pathway mediated the efficacy of 7n. Our study provides powerful information for developing this kind of compound into a new class of anti-NAFLD candidates, and compound 7n is worthy of further investigation as an ideal lead compound.

Lactoferrin modification of berberine nanoliposomes enhances the neuroprotective effects in a mouse model of Alzheimer's disease.

Previous studies have shown that berberine has neuroprotective effects against Alzheimer's disease, including antagonizing tau phosphorylation, and inhibiting acetylcholinesterase activity and neural cell apoptosis. However, its low bioavailability and adverse reactions with conventional administration limit its clinical application. In this study, we prepared berberine nanoliposomes using liposomes characterized by low toxicity, high entrapment efficiency, and biodegradability, and modified them with lactoferrin. Lactoferrin-modified berberine nanoliposomes had uniform particle size and high entrapment efficiency. We used the lactoferrin-modified berberine nanoliposomes to treat a mouse model of Alzheimer's disease established by injection of amyloid-beta 1-42 into the lateral ventricle. Lactoferrin-modified berberine nanoliposomes inhibited acetylcholinesterase activity and apoptosis in the hippocampus, reduced tau over-phosphorylation in the cerebral cortex, and improved mouse behavior. These findings suggest that modification with lactoferrin can enhance the neuroprotective effects of berberine nanoliposomes in Alzheimer's disease.

Anti-hypertensive and endothelia protective effects of Fufang Qima capsule on primary hypertension via adiponectin/adenosine monophosphate activated protein kinase pathway.

OBJECTIVE: To investigate the potential mechanism of the vascular remodeling effect and provide additional information about anti-hypertension activity of Fufang Qima capsule. METHODS: Spontaneous hypertensive rats (SHRs) were used to study the underlying mechanism of the anti-hypertension activity of QM. In this study, SHRs were randomly divided into 5 groups: model group, Telmisartan group (7.2 mg/kg, p.o.), and three QM groups (0.9298, 1.8596, and 3.7192 g/kg, p.o.). Wistar Kyoto rats (WKY) were used as normal control group. Blood pressure (BP), aorta, perivascular adipose tissue (PVAT) histology were investigated to evaluate the effect of QM. Nitric oxide (NO) and endothelial nitric oxide synthase (eNOS) phosphorylation were measured. Adiponectin (APN) secretion, as well as APN signal pathway proteins including APN, adiponectin receptors (R1 and R2) and adenosine 5'-monophosphate-activated protein kinase (AMPK) were all analyzed. RESULTS: QM significantly reduced BP and ameliorated the vascular pathological change, i.e. intima media thicken and collagen fiber hyperplasia. Meanwhile, QM increased concentration of NO and the phosphorylation of eNOS in the aorta. The anti-hypertensive and endothelia-protective effect of QM could be attributed to activating APN/ AMPK pathway by up-regulating the expression of APN in PVAT and APN Receptor 2, AMPKα and phosphorylated AMPKα in the aorta. CONCLUSION: The QM alleviation effect mechanism for primary hypertension was via modulating the APN/AMPK signal pathway.

Structure-activity relationship and biological evaluation of 12 N-substituted aloperine derivatives as PD-L1 down-regulatory agents through proteasome pathway.

Twenty-nine 12 N-substituted aloperine derivatives were synthesized and screened for suppression on PD-L1 expression in H460 cells, as a continuation of our work. Systematic structural modifications led to the identification of compound 6b as the most active PD-L1 modulator. Compound 6b could significantly down-regulate both constitutive and inductive PD-L1 expression in NSCLC cells, and successively enhance the cytotoxicity of co-cultured T cells against tumor cells at the concentration of 20 µM. Also, it exhibited a moderate in vivo anticancer efficacy against Lewis tumor xenograft with a stable PK and safety profile. The mechanism study indicated that 6b mediated the degradation of PD-L1 through a proteasome pathway, rather than a lysosome route. These results provided the powerful information for cancer immunotherapy of aloperine derivatives with unique endocyclic skeleton by targeting PD-L1 to activate immune cells to kill cancer cells.

Discovery and evolution of 12N-substituted aloperine derivatives as anti-SARS-CoV-2 agents through targeting late entry stage.

So far, there is still no specific drug against COVID-19. Taking compound 1 with anti-EBOV activity as the lead, fifty-four 12N-substituted aloperine derivatives were synthesized and evaluated for the anti-SARS-CoV-2 activities using pseudotyped virus model. Among them, 8a exhibited the most potential effects against both pseudotyped and authentic SARS-CoV-2, as well as SARS-CoV and MERS-CoV, indicating a broad-spectrum anti-coronavirus profile. The mechanism study disclosed that 8a might block a late stage of viral entry, mainly via inhibiting host cathepsin B activity rather than directly targeting cathepsin B protein. Also, 8a could significantly reduce the release of multiple inflammatory cytokines in a time- and dose-dependent manner, such as IL-6, IL-1ß, IL-8 and MCP-1, the major contributors to cytokine storm. Therefore, 8a is a promising agent with the advantages of broad-spectrum anti-coronavirus and anti-cytokine effects, thus worthy of further investigation.

Neuroprotective Effect of Fructus broussonetiae on APP/PS1 Mice via Upregulation of AKT/ß-Catenin Signaling.

OBJECTIVE: To evaluate the mechanisms underlying the protective effect of Chinese herbal medicine Fructus broussonetiae (FB) in both mouse and cell models of Alzheimer's disease (AD). METHODS: APP/PS1 mice treated with FB for 2 months and vehicle-treated controls were run through the Morris water maze and object recognition test to evaluate learning and memory capacity. RNA-Seq, Western blotting, and immunofluorescence staining were also conducted to evaluate the effects of FB treatment on various signaling pathways altered in APP/PS1 mice. To further explore the mechanisms underlying FB's protective effect, PC-12 cells were treated with Aß25-35 in order to establish an in vitro model of AD. RESULTS: FB-treated mice showed improved learning and memory capacity on both the Morris water maze and object recognition tests. RNA-seq of hippocampal tissue from APP/PS1 mice showed that FB had effects on multiple signaling pathways, specifically decreasing cell apoptotic signaling and increasing AKT and ß-catenin signaling. Similarly, FB up-regulated both AKT and ß-catenin signaling in PC-12 cells pre-treated with Aß25-35, in which AKT positively regulated ß-catenin signaling. Further study showed that AKT promoted ß-catenin signaling via enhancing ß-catenin (Ser552) phosphorylation. Moreover, AKT and ß-catenin signaling inhibition both resulted in the attenuated survival of FB-treated cells, indicating the AKT/ß-catenin signaling is a crucial mediator in FB promoted cell survival. CONCLUSIONS: FB exerted neuroprotective effects on hippocampal cells of APP/PS1 mice, as well as improved cell viability in an in vitro model of AD. The protective actions of FB occurred via the upregulation of AKT/ß-catenin signaling.

Studies on Dissipations and Residues of Indoxacarb under Different Field and Environmental Conditions.

Indoxacarb is a broad-spectrum insecticide and widely used in agriculture. The dissipations and residues of indoxacarb were researched at three different field sites in Beijing, Hunan, and Zhejiang provinces in China. Analytical methods for determining the residue of indoxacarb in paddy water, paddy soil, rice straw, rice hull, and brown rice were described. Indoxacarb residues were extracted from samples, cleaned up by solid phase extraction, and determined by high-performance liquid chromatography coupled with tandem mass spectrometry in the selected ion monitoring mode. The recoveries in paddy water, paddy soil, rice straw, rice hull, and brown rice matrices at three spiking levels ranged from 79.7% to 98.3%, respectively. The field and environmental conditions would affect the dissipations and residues of indoxacarb. The time to dissipate 50% of indoxacarb in paddy water, paddy soil, and rice straw was less than 9 days. The terminal residues obtained from Beijing at preharvest interval of 14 and 21 days were higher than the maximum limit of European Union. Therefore, a dosage of 24 g a. i. ha-1 at 28 days preharvest interval with 3 spraying times was recommended. Such accumulation of measured data is necessary to provide guidance for the proper and safe use of this pesticide.

Structure-activity relationship and hypoglycemic activity of tricyclic matrines with advantage of treating diabetic nephropathy.

Forty-three tricyclic matrinic derivatives with a unique scaffold were prepared and evaluated for their stimulation effects on glucose consumption in HepG2 cells. The structure-activity relationship was systematically elucidated for the first time. Among them, compound 17a exhibited the most promising potency, and dose-dependently increased glucose consumption in L6 myotubes. It significantly lowered blood glucose, glucosylated haemoglobin and AGE level, and improved glucose tolerance and insulin resistance in KK-Ay mice as well. More importantly, 17a effectively ameliorated diabetic nephropathy (DN), as indicated by the improvement of renal function and pathological changes, and decrease of urinary protein. Furthermore, 17a could induce glycolysis but suppressed aerobic oxidation of glucose, in a similar mechanism to Metform. Our results indicated that in addition to hyperglycemia, 17a may be developed to treat diabetic complication such as DN.

Skin-patch of Xin Huang Pian on relieving joint symptoms in patients with acute gouty arthritis: A Randomized, Double-Blind, Active-Controlled Trial.

AIMS: To evaluate the effectiveness and safety of Xin Huang Pian skin patches for patients with acute gouty arthritis. BACKGROUND: In China, patients with acute gouty arthritis benefit from skin patcheses with herbal medicines. But the clinical effects of skin patches with Xin Huang Pian are rarely reported. DESIGN: A Randomized, Double-Blind, Active-Controlled Trial. METHODS: The trial was performed from January 2015-December 2018 at the First Affiliated Hospital of Sun Yat-sen University in China. It was conducted with one intervention group (skin patches of Xin Huang Pian, N = 30) and one active control group (skin patches of Diclofenac Diethylamine Emulgel, N = 31). Participants and study investigators were both blinded to the treatment assignments. The primary outcomes were the improvement of joints' symptoms. The secondary outcomes were changes in white blood cells, erythrocyte sedimentation rate and C-reactive protein. RESULTS: Skin patches of Xin Huang Pian showed quick effect on decreasing joint pain at 3rd day of treatment. Wherever only at 7th day, Diclofenac Diethylamine Emulgel markedly lowered joint pain. Xin Huang Pian also showed superior effect than Diclofenac Diethylamine Emulgel on improving joint swelling and range of motion and decreasing the levels of C-reactive protein and erythrocyte sedimentation rate. No adverse reactions were observed in skin patches of Xin Huang Pian treatment. CONCLUSION: Skin patches of Xin Huang Pian appeared to be safe and efficacious for relieving joint symptoms in patients with acute gouty arthritis. The mechanism might be associated with the decreased levels of C-reactive protein and erythrocyte sedimentation rate. IMPACT: Skin-patcheses with Xin Huang Pian are more effective than Diclofenac Diethylamine Emulgel on improving joint pain, swelling and range of motion. Xin Huang Pian treatment showed superior effects compared with Diclofenac Diethylamine Emulgel on decreasing levels of C-reactive protein and erythrocyte sedimentation rate. Patients with acute gouty arthritis may benefit from skin patches of Xin Huang Pian for effective relief from joint pain and swelling. Chinese Clinical Trial Registration: ChiCTR-TRC-1300 4122.

Clinical trials, progression-speed differentiating features and swiftness rule of the innovative targets of first-in-class drugs.

Drugs produce their therapeutic effects by modulating specific targets, and there are 89 innovative targets of first-in-class drugs approved in 2004-17, each with information about drug clinical trial dated back to 1984. Analysis of the clinical trial timelines of these targets may reveal the trial-speed differentiating features for facilitating target assessment. Here we present a comprehensive analysis of all these 89 targets, following the earlier studies for prospective prediction of clinical success of the targets of clinical trial drugs. Our analysis confirmed the literature-reported common druggability characteristics for clinical success of these innovative targets, exposed trial-speed differentiating features associated to the on-target and off-target collateral effects in humans and further revealed a simple rule for identifying the speedy human targets through clinical trials (from the earliest phase I to the 1st drug approval within 8 years). This simple rule correctly identified 75.0% of the 28 speedy human targets and only unexpectedly misclassified 13.2% of 53 non-speedy human targets. Certain extraordinary circumstances were also discovered to likely contribute to the misclassification of some human targets by this simple rule. Investigation and knowledge of trial-speed differentiating features enable prioritized drug discovery and development.

Protective effects of organic extracts of Alpinia oxyphylla against hydrogen peroxide-induced cytotoxicity in PC12 cells.

Alpinia oxyphylla, a traditional herb, is widely used for its neuroprotective, antioxidant and memory-improving effects. However, the neuroprotective mechanisms of action of its active ingredients are unclear. In this study, we investigated the neuroprotective effects of various organic extracts of Alpinia oxyphylla on PC12 cells exposed to hydrogen peroxide-induced oxidative injury in vitro. Alpinia oxyphylla was extracted three times with 95% ethanol (representing extracts 1-3). The third 95% ethanol extract was dried and resuspended in water, and then extracted successively with petroleum ether, ethyl acetate and n-butanol (representing extracts 4-6). The cell counting kit-8 assay and microscopy were used to evaluate cell viability and observe the morphology of PC12 cells. The protective effect of the three ethanol extracts (at tested concentrations of 50, 100 and 200 µg/mL) against cytotoxicity to PC12 cells increased in a concentration-dependent manner. The ethyl acetate, petroleum ether and n-butanol extracts (each tested at 100, 150 and 200 µg/mL) had neuroprotective effects as well. The optimum effective concentration ranged from 50-200 µg/mL, and the protective effect of the ethyl acetate extract was comparatively robust. These results demonstrate that organic extracts of Alpinia oxyphylla protect PC12 cells against apoptosis induced by hydrogen peroxide. Our findings should help identify the bioactive neuroprotective components in Alpinia oxyphylla.

circMTDH.4/miR-630/AEG-1 axis participates in the regulation of proliferation, migration, invasion, chemoresistance, and radioresistance of NSCLC.

Astrocyte elevated gene-1 (AEG-1) plays a critical role in the development, progression, and metastasis of a variety of cancers, including non-small-cell lung cancer (NSCLC). The objective of the current study is to unravel the upstream signaling of AEG-1. A cohort of 28 NSCLC tissues and 30 normal tissues were collected. Quantitative reverse transcription-polymerase chain reaction and Western blotting were used to examine AEG-1, migration, and invasion related markers in NSCLC cells. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay coupled with colony formation assay were conducted to monitor cell growth. Transwell assay was performed to determine cell migration and invasion. Apoptotic cells were detected by costaining with Annexin-V-fluorescein isothiocyanate and propidium iodide. Immunofluorescent staining was used to observe the levels of migration and invasion related markers. Xenograft models were used to investigate tumor formation in vivo. Dual-luciferase reporter assay and RNA immunoprecipitation were carried out to determine the interaction between circMTDH.4 and miR-630, as well as the associated between miR-630 and AEG-1. AEG-1 was highly expressed in NSCLC tissues and cell lines. Silencing of AEG-1 inhibited cell proliferation, migration, invasion, and chemoresistance/radioresistance in NCI-H1650 and A549 cells. circMTDH.4 regulated AEG-1 expression via sponging miR-630. Knockdown of circMTDH.4 and/or overexpression of miR-630 inhibited chemoresistance and radioresistance in NSCLC cells, whereas overexpression of AEG-1 or knockdown of miR-630 exerted rescue effects. circMTDH.4/miR-630/AEG-1 axis is responsible for chemoresistance and radioresistance in NSCLC cells.

[Treatment of scapulohumeral periarthritis by Fuyang-pot warming combined with electroacupuncture stimulation].

OBJECTIVE: To observe the clinical therapeutic effect of Fuyang-pot warming combined with electroacupuncture (EA) in the treatment of scapulohumeral periarthritis (SPA). METHODS: A total of 90 cases of SPA patients were randomized into EA, Fuyang-pot warming and EA plus Fuyang-pot warming (combination) groups (n=30 per group). Fuyang-pot warming including pressing, mild moxibustion, scraping-pushing, cupping, tapping, etc. was applied to Fengchi (GB20), Dazhui (GV14), Jianjing (GB21), Jianyu (LI15), Zhongfu (LU1), Ashi-point, etc., and EA (2 Hz /100 Hz,1-1.5 mA) was appled to GB20, GV14, GB21, LI15, Binao (LI14), Tiaokou (ST38), Chengshan (BL57), Ashi-point, etc. The treatment was performed for 30 min every time, once every other day for 2 weeks. The visual analogue scale (VAS, 0-10 points) was used to assess the pain severity. The Constant-Murley shoulder assessment scale (100 points in total, including 15 points in pain severity and 20 points in daily living activities, 40 points in joint motion range, and 25 points in myodynamia) was used to assess the functional state of the shoulder. The rating scale of the American Shoulder and Elbow Surgeons (ASES, 4 grades) was used to evaluate the ability of daily living activities. RESULTS: Following the treatment, intra-group comparison showed that the VAS score was significantly reduced in the three groups in comparison with their own pre-treatment (P<0.01). The total scores of Constant-Murley scale, and scores of activities of daily living and active motion range, myodynamia, and ASES shoulder-joint function were all considerably increased in the three groups in comparison with their own pre-treatment (all P<0.01). The therapeutic effect of EA plus Fuyang-pot warming was significantly superior to that of simple EA and simple Fuyang-pot warming in reducing VAS score and increasing total score of Constant-Murley scale and scores of activities of daily living, active motion range, myodynamia as well as ASES shoulder joint function (P<0.01). Of the 30, 29 and 30 cases in the combination, EA and Fuyang-pot warming groups, 9, 2 and 4 were basically cured, 14, 8 and 12 experienced marked improvement, 4, 12 and 9 were improved, and 3, 7 and 5 failed in the treatment, with the cured plus effective rates being 76.67%, 34.48% and 53.33%, respectively. The cure plus effective rate was apparently higher in the combined treatment group than in the simple EA and simple Fuyang-pot warming groups (P<0.01), but had no significant difference between the simple EA and simple Fuyang-pot warming groups (P>0.05). CONCLUSION: Fuyang-pot warming combined with EA is effective in relieving pain, and enhancing the daily life quality in scapulohumeral periarthritis patients.

Synthesis and Evolution of Berberine Derivatives as a New Class of Antiviral Agents against Enterovirus 71 through the MEK/ERK Pathway and Autophagy.

Taking berberine (BBR) as the lead, 23 new BBR derivatives were synthesized and examined for their antiviral activities against four different genotype enterovirus 71 (EV71) strains with a cytopathic effect (CPE) assay. Structure-activity relationship (SAR) studies indicated that introduction of a suitable substituent at the 9-position might be beneficial for potency. Among them, compound 2d exhibited most potent activities with IC50 values of 7.12⁻14.8 µM, similar to that of BBR. The effect of 2d was further confirmed in a dose-dependent manner both in RNA and protein level. The mechanism revealed that 2d could inhibit the activation of MEK/ERK signaling pathway. Meanwhile, it could suppress the EV71-induced autophagy by activating AKT and inhibiting the phosphorylation of JNK and PI3KIII proteins. We consider BBR derivatives to be a new family of anti-EV71 agents through targeting host components, with an advantage of broad-spectrum anti-EV71 potency.

Prediction of the binding mode and resistance profile for a dual-target pyrrolyl diketo acid scaffold against HIV-1 integrase and reverse-transcriptase-associated ribonuclease H.

The rapid emergence of drug-resistant variants is one of the most common causes of highly active antiretroviral therapeutic (HAART) failure in patients infected with HIV-1. Compared with the existing HAART, the recently developed pyrrolyl diketo acid scaffold targeting both HIV-1 integrase (IN) and reverse transcriptase-associated ribonuclease H (RNase H) is an efficient approach to counteract the failure of anti-HIV treatment due to drug resistance. However, the binding mode and potential resistance profile of these inhibitors with important mechanistic principles remain poorly understood. To address this issue, an integrated computational method was employed to investigate the binding mode of inhibitor JMC6F with HIV-1 IN and RNase H. By using per-residue binding free energy decomposition analysis, the following residues: Asp64, Thr66, Leu68, Asp116, Tyr143, Gln148 and Glu152 in IN, Asp443, Glu478, Trp536, Lys541 and Asp549 in RNase H were identified as key residues for JMC6F binding. And then computational alanine scanning was carried to further verify the key residues. Moreover, the resistance profile of the currently known major mutations in HIV-1 IN and 2 mutations in RNase H against JMC6F was predicted by in silico mutagenesis studies. The results demonstrated that only three mutations in HIV-1 IN (Y143C, Q148R and N155H) and two mutations in HIV-1 RNase H (Y501R and Y501W) resulted in a reduction of JMC6F potency, thus indicating their potential role in providing resistance to JMC6F. These data provided important insights into the binding mode and resistance profile of the inhibitors with a pyrrolyl diketo acid scaffold in HIV-1 IN and RNase H, which would be helpful for the development of more effective dual HIV-1 IN and RNase H inhibitors.

Discovery and evolution of aloperine derivatives as novel anti-filovirus agents through targeting entry stage.

Preventing filoviruses in the entry stage is an attractive antiviral strategy. Taking aloperine, a Chinese natural herb with an endocyclic skeleton, as the lead, 23 new aloperine derivatives were synthesized and evaluated for their anti-filovirus activities including ebola virus (EBOV) and marburg virus (MARV) using pseudotyped virus model. Structure-activity relationship (SAR) analysis indicated that the introduction of a 12N-dichlorobenzyl group was beneficial for the potency. Compound 2e exhibited the most potent anti-EBOV and anti-MARV effects both in vitro and in vivo. It also displayed a good pharmacokinetic and safety profile in vivo, indicating an ideal druglike feature. The primary mechanism study showed that 2e could block a late stage of viral entry, mainly through inhibiting cysteine cathepsin B activity of host components. We consider compound 2e to be a promising broad-spectrum anti-filovirus agent with the advantages of a unique chemical scaffold and a specific biological mechanism.

Synthesis and Biological Evaluation of 12N-substituted Tricyclic Matrinic Derivatives as a Novel Family of Anti-Influenza Agents.

BACKGROUND: Influenza is still a serious threat to human health with significant morbidity and mortality, so it is desirable to develop novel anti-flu drug agents with novel structures. OBJECTIVE: The main purpose of this research was to explore broad-spectrum anti-flu agents and provide antiviral stockpiles in response to potential future influenza pandemics. METHODS: Fifteen novel 12N-substituted tricyclic matrinic derivatives were synthesized and evaluated for their anti-influenza activities against H1N1 subtype taking 12N-p-cyanobenzenesulfonyl matrinane (1) as the lead. All prepared compounds were characterized by 1H NMR, 13C NMR and ESI-HRMS. The pharmacokinetics (PK) profile of the key compound was also examined in this study. RESULT: The structure-activity relationship study indicated that suitable benzyl groups on 12N atom might be beneficial for the activity. Among them, 12N-p-carboxybenzyl matrinic butane (17g) exhibited the most promising activity with an IC50 value of 16.2 µM and a selective index (SI) value of over 33.4. In addition, compound 17g displayed a good in vivo pharmacokinetic profile with an area under the curve (AUC0-∞) value of 9.89 µM·h. CONCLUSION: We consider tricyclic matrinic butane derivatives to be a new class of anti-influenza agents and this study provided useful information on further optimization.

Assessing the Performances of Protein Function Prediction Algorithms from the Perspectives of Identification Accuracy and False Discovery Rate.

The function of a protein is of great interest in the cutting-edge research of biological mechanisms, disease development and drug/target discovery. Besides experimental explorations, a variety of computational methods have been designed to predict protein function. Among these in silico methods, the prediction of BLAST is based on protein sequence similarity, while that of machine learning is also based on the sequence, but without the consideration of their similarity. This unique characteristic of machine learning makes it a good complement to BLAST and many other approaches in predicting the function of remotely relevant proteins and the homologous proteins of distinct function. However, the identification accuracies of these in silico methods and their false discovery rate have not yet been assessed so far, which greatly limits the usage of these algorithms. Herein, a comprehensive comparison of the performances among four popular prediction algorithms (BLAST, SVM, PNN and KNN) was conducted. In particular, the performance of these methods was systematically assessed by four standard statistical indexes based on the independent test datasets of 93 functional protein families defined by UniProtKB keywords. Moreover, the false discovery rates of these algorithms were evaluated by scanning the genomes of four representative model organisms (Homo sapiens, Arabidopsis thaliana, Saccharomyces cerevisiae and Mycobacterium tuberculosis). As a result, the substantially higher sensitivity of SVM and BLAST was observed compared with that of PNN and KNN. However, the machine learning algorithms (PNN, KNN and SVM) were found capable of substantially reducing the false discovery rate (SVM < PNN < KNN). In sum, this study comprehensively assessed the performance of four popular algorithms applied to protein function prediction, which could facilitate the selection of the most appropriate method in the related biomedical research.

Discovery and evolution of aloperine derivatives as a new family of HCV inhibitors with novel mechanism.

Aloperine (1), a Chinese natural product with a unique endocyclic scaffold, was first identified to be a potent hepatitis C virus (HCV) inhibitor in our laboratory. Thirty-four new aloperine derivatives were designed, synthesized and evaluated for their anti-HCV activities taking 1 as the lead. Among them, compound 7f exhibited the potential potency with EC50 values in a micromolar range against both wild-type and direct-acting antiviral agents (DAAs)-resistant variants, and synergistically inhibited HCV replication with approved DAAs. Furthermore, it also owned a good oral pharmacokinetic and safety profile, suggesting a highly druglike nature. The primary mechanism showed that 7f might target host components, distinctly different from the DAAs currently used in clinic. Therefore, we consider aloperine derivatives to be a novel class of anti-HCV agents, and compound 7f has been selected as a promising antiviral candidate for further investigation.