RESUMO
It's urgent to discover new antibiotics along with the increasing emergence and dissemination of multidrug resistant (MDR) bacterial pathogens. In the present investigation, morusin exhibited rapid bactericidal activity against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) by targeting the phospholipid of bacterial inner membrane, increasing membrane rigidity and disrupting bacterial homeostasis together with the membrane permeability, which caused fundamental metabolic disorders. Furthermore, morusin can also accumulate ROS, suppress H2S production, and aggravate oxidative damage in bacteria. Importantly, morusin also inhibited the spread of wounds and reduced the bacterial burden in the mouse model of skin infection caused by MRSA. It's a chance to meet the challenge of existing antibiotic resistance and avoid the development of bacterial resistance, given the multiple targets of morusin.
Assuntos
Staphylococcus aureus Resistente à Meticilina , Morus , Animais , Camundongos , Antibacterianos/farmacologia , Testes de Sensibilidade MicrobianaRESUMO
BACKGROUND: Anxiety and depression can influence adherence to Pre-exposure Prophylaxis (PrEP). However, there is limited research on the temporal dynamics of anxiety and depression among men who have sex with men (MSM) using PrEP. METHODS: From December 2018 to November 2020, we administered the Hospital Anxiety and Depression Scale (HADS) to participants in the China Real-World Oral Intake of PrEP (CROPrEP) to measure their anxiety and depression levels. The group-based trajectory model (GBTM) depicted the dynamic changes of anxiety and depression scores over time. RESULTS: A total of 1023 MSM were included, with 4523 follow-up assessments. The GBTM categorized the trajectories into three distinct patterns: consistently low (54.8% for anxiety, 60.7% for depression), consistently moderate (39.3% for anxiety, 31.4% for depression), and high but bell-shaped (5.9% for anxiety, 7.9% for depression). Higher anxiety levels were associated with being aged 18-30 years old, earning less than US$619 per month, female-identifying, adopting the bottom sexual role with men, and having two or more anal sex partners in the past three months; similarly, higher depression levels correlated with a monthly income under US$619, female-identifying, sexual behavior as bottom and a positive syphilis at baseline. PrEP adherence was notably lower in the high but bell-shaped anxiety and depression group compared to the other groups, particularly at the 12th-month follow-up. CONCLUSIONS: Close monitoring of anxiety and depression levels in MSM on PrEP is crucial. Provision of targeted mental health support is essential to enhance PrEP effectiveness.
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Fármacos Anti-HIV , Infecções por HIV , Profilaxia Pré-Exposição , Minorias Sexuais e de Gênero , Masculino , Humanos , Feminino , Adolescente , Adulto Jovem , Adulto , Homossexualidade Masculina , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Infecções por HIV/tratamento farmacológico , Tenofovir/uso terapêutico , Depressão/epidemiologia , Fármacos Anti-HIV/uso terapêutico , Adesão à Medicação , Comportamento Sexual , Ansiedade/epidemiologia , China/epidemiologiaRESUMO
Monoterpene indole alkaloids exhibit structural diversity in herbal resources and have been developed as promising drugs owing to their significant biological activities. Confidential identification and quantification of monoterpene indole alkaloids is the key to quality control of target plants in industrial production but has rarely been reported. In this study, quantitative performance of three data acquisition modes of ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry including full scan, auto-MS2 and target-MS2 , was evaluated and compared for specificity, sensitivity, linearity, precision, accuracy, and matrix effect using five monoterpene indole alkaloids (scholaricine, 19-epi-scholaricine, vallesamine, picrinine, and picralinal). Method validations indicated that target-MS2 mode showed predominant performance for simultaneous annotation and quantification of analytes, and was then applied to determine monoterpene indole alkaloids in Alstonia scholaris (leaves, barks) after extraction procedures optimization using Box-Behnken design of response surface methodology. The variations of A. scholaris monoterpene indole alkaloids in different plant parts, harvest periods, and post-handling processes, were subsequently investigated. The results indicated that target-MS2 mode could improve the quantitative capability of ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry for structure-complex monoterpene indole alkaloids in herbal matrices. Alstonia scholaris, monoterpene indole alkaloids, quadrupole time of flight mass spectrometry, qualitative and quantitative analysis, ultra-high-performance liquid chromatography.
Assuntos
Alstonia , Alcaloides de Triptamina e Secologanina , Cromatografia Líquida de Alta Pressão , Alstonia/química , Alcaloides Indólicos/química , Espectrometria de Massas/métodos , MonoterpenosRESUMO
Our previous study showed 1-Nitropyrene (1-NP) exposure disrupted testicular testosterone synthesis in mouse, but the exact mechanism needs further investigation. The present research found 4-phenylbutyric acid (4-PBA), an endoplasmic reticulum (ER) stress inhibitor, recovered 1-NP-induced ER stress and testosterone synthases reduction in TM3 cells. GSK2606414, a protein kinase-like ER kinase (PERK) kinase inhibitor, attenuated 1-NP-induced PERK-eukaryotic translation initiation factor 2α (eIF2α) signaling activation and downregulation of steroidogenic proteins in TM3 cells. Both 4-PBA and GSK2606414 attenuated 1-NP-induced steroidogenesis disruption in TM3 cells. Further studies used N-Acetyl-L-cysteine (NAC) as a classical antioxidant to explore whether oxidative stress-activated ER stress mediated 1-NP-induced testosterone synthases reduction and steroidogenesis disruption in TM3 cells and mouse testes. The results showed NAC pretreatment mitigated oxidative stress, and subsequently attenuated ER stress, particularly PERK-eIF2α signaling activation, and downregulation of testosterone synthases in 1-NP-treated TM3 cells. More importantly, NAC extenuated 1-NP-induced testosterone synthesis in vitro and in vivo. The current work indicated that oxidative stress-caused ER stress, particularly PERK-eIF2α pathway activation, mediates 1-NP-downregulated steroidogenic proteins and steroidogenesis disruption in TM3 cells and mouse testes. Significantly, the current study provides a theoretical basis and demonstrates the experimental evidence for the potential application of antioxidant, such as NAC, in public health prevention, particularly in 1-NP-induced endocrine disorder.
Assuntos
Antioxidantes , Testículo , Masculino , Camundongos , Animais , Testículo/metabolismo , Antioxidantes/metabolismo , Fator de Iniciação 2 em Eucariotos/metabolismo , Estresse do Retículo Endoplasmático/fisiologia , Testosterona/metabolismo , Estresse Oxidativo , Acetilcisteína/farmacologia , Acetilcisteína/metabolismoRESUMO
Neothalfine is a natural bisbenzylisoquinoline alkaloid with the abundant resource in medicinal plants and has not been reported its anti-tumor efficacy. In the present study, the anti-tumor efficacy was investigated and it showed broad-spectrum activity against several cancer cell lines, especially metastatic colorectal cancer (HCT116, SW620, T84) with the IC50 values of 7.2, 5.9, 8.2 nM, respectively, roughly equal to well-known anti-tumor agent docetaxel (4.0, 4.7, 2.7 nM) and nearly 1000 folds than CPT-11 (4.4, 5.1, 6.9 µM). Furthermore, neothalfine inhibited colorectal cell proliferation by resulting in cell cycle arrest at the G2/M phase and induced apoptosis through the dysfunction of mitochondria to trigger intrinsic apoptotic pathway by untargeted metabolomic method, mitochondrial membrane potential, and caspase-3/7 activity assay. Moreover, neothalfine damaged colorectal cancer clonal spheres expansion significantly at the concentration of 3.5 nM with nearly 1000 folds efficacy than CPT-11 (3.0 µM). The results supported that neothalfine might be an anti-tumor lead for further investigation.
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Antineoplásicos/farmacologia , Produtos Biológicos/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Antineoplásicos/química , Produtos Biológicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/patologia , Neoplasias Colorretais/secundário , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
INTRODUCTION: The structural annotation of target relies on high-resolution mass spectrometry (HRMS) information resulting in dubious identities in most cases. The accurate annotation of isomeric structures is still challenging to be confirmed with significant bottleneck. OBJECTIVE: This study focused on the improvement of structural annotation of candidate structures via four pairs of isomeric flavanone-7-O-diglucosides and their basic flavanone aglycones commonly detected in citrus products. METHOD: An integrated liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) approach merging retention time, accurate mass, tandem mass spectrometry (MS/MS) information (diagnostic ions), ion ratio at selected collision energy was established successfully. RESULTS: Feasibility of this approach was validated confidently in biological samples with relative standard deviation (RSD) of ion ratio range from 3.91 to 12.28%. Differences of fragmentation patterns of citrus flavanones were illustrated reasonably. MS/MS fragments of (S)-hesperetin and (S)-isosakuranetin were complicated and showed typical radical ion [1,2 A - H]â¢- (m/z 164) in negative ESI mode due to the methoxyl group on B-ring, which showed huge difference with (R)-hesperetin and (R)-isosakuranetin. CONCLUSION: This study integrated multiple levels to boost the confidence of structural annotation relied on LC-HRMS, and provided important values in practice for precise identification of citrus flavanones in biological matrices.
Assuntos
Citrus , Flavanonas , Cromatografia Líquida , Flavanonas/análise , Humanos , Isomerismo , Espectrometria de Massas em TandemRESUMO
The citrus herbs have proved their important medicinal and nutritional values as medicine-food dual-purpose herbs, functional foods, or medical herbs in China. In this study, phytochemicals and antioxidant activity among ten typical citrus herbs (ethanol extracts) were investigated comprehensively. The major ingredients and their contents were analyzed by high-resolution mass spectrometry, and the differences of typical fragment ions between flavanone-7-O-rutinoside(s) and flavanone-7-O-neohesperidoside(s) were discriminated properly in negative electrospray ionization mode. Total polyphenols, total flavonoids, 1,1-diphenyl-2-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), and ferric reducing antioxidant power tests were performed, which indicated their beneficial values and antioxidant effects. The medicine-food dual-purpose herbs including Chenpi, Juluo, Daidaihua, Huajuhong, Xiangyuan, and Foshou exhibited antioxidant capacities significantly by decreasing intracellular reactive oxygen species intensity (P < 0.01), enhancing superoxide dismutase, catalase, and glutathione peroxidase activities (P < 0.01) in H2 O2 -induced RIN-m5F cells. Moreover, the functional foods Zhishi, Zhiqiao, and Qingpi showed moderate antioxidant bioactivity, while the medical herb Juhe showed weak antioxidant bioactivity, which were consistent with the multivariate analysis of their major flavonoids. The study provided a new sight for the chemical differentiation and practical application of citrus herbs as medicine-food dual-purpose herbs, functional foods, or medical herbs.
Assuntos
Antioxidantes/farmacologia , Citrus/química , Medicamentos de Ervas Chinesas/farmacologia , Extratos Vegetais/farmacologia , Animais , Antioxidantes/química , Antioxidantes/metabolismo , Benzotiazóis/antagonistas & inibidores , Compostos de Bifenilo/antagonistas & inibidores , Linhagem Celular , Técnicas de Química Analítica , Físico-Química , China , Cromatografia Líquida de Alta Pressão , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/metabolismo , Peróxido de Hidrogênio/antagonistas & inibidores , Metabolômica , Picratos/antagonistas & inibidores , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Ratos , Espectrometria de Massas por Ionização por Electrospray , Ácidos Sulfônicos/antagonistas & inibidoresRESUMO
Sirtuin 6 (SIRT6) is an NAD+-dependent deacetylase with a significant role in 20% of all cancers, such as colon cancers and rectal adenocarcinoma. However, there is currently no effective drug for cancers related to SIRT6. To explore potential inhibitors of SIRT6, it is essential to reveal details of the interaction mechanisms between inhibitors and SIRT6 at the atomic level. The nature of small molecules from herbs have many advantages as inhibitors. Based on the conformational characteristics of the inhibitor Compound 9 (Asinex ID: BAS13555470), we explored the natural molecule Scutellarin, one compound of Huang Qin, which is an effective herb for curing cancer that has been described in the Traditional Chinese Medicine (TCMS) library. We investigated the interactions between SIRT6 and the inhibitors using molecular dynamics (MD) simulations. We illustrated that the structurally similar inhibitors have a similar binding mode to SIRT6 with residues-Leu9, Phe64, Val115, His133 and Trp188. Hydrophobic and π-stacking interactions play important roles in the interactions between SIRT6 and inhibitors. In summary, our results reveal the interactive mechanism of SIRT6 and the inhibitors and we also provide Scutellarin as a new potential inhibitor of SIRT6. Our study provides a new potential way to explore potential inhibitors from TCMS.
Assuntos
Descoberta de Drogas , Modelos Moleculares , Sirtuínas/antagonistas & inibidores , Sirtuínas/química , Sequência de Aminoácidos , Sítios de Ligação , Humanos , Ligantes , Conformação Molecular , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Ligação Proteica , Relação Estrutura-AtividadeRESUMO
1-Nitropyrene (1-NP) is a neurodevelopmental toxicant. This study was to evaluate the impact of exposure to 1-NP after weaning on anxiety-like behavior. Five-week-old mice were administered with 1-NP (0.1 or 1 mg/kg) daily for 4 weeks. Anxiety-like behaviour was measured using elevated-plus maze (EPM) and open field test (OFT). In EPM test, time spending in open arm and times entering open arm were reduced in 1-NP-treated mice. In OFT test, time spent in the center region and times entering the center region were diminished in 1-NP-treated mice. Prefrontal dendritic length and number of dendrite branches were decreased in 1-NP-treated mice. Prefrontal PSD95, an excitatory postsynaptic membrane protein, and gephyrin, an inhibitory postsynaptic membrane protein, were downregulated in 1-NP-treated mice. Further analysis showed that peripheral steroid hormones, including serum testosterone (T) and estradiol (E2), testicular T, and ovarian E2, were decreased in 1-NP-treated mice. Interestingly, T and E2 were diminished in 1-NP-treated prefrontal cortex. Prefrontal T and E2 synthases were diminished in 1-NP-treated mice. Mechanistically, GCN2-eIF2α, a critical pathway that regulates ribosomal protein translation, was activated in 1-NP-treated prefrontal cortex. These results indicate that exposure to 1-NP after weaning induces anxiety-like behaviour partially by inhibiting steroid hormone synthesis in prefrontal cortex.
Assuntos
Ansiedade , Córtex Pré-Frontal , Pirenos , Desmame , Animais , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Ansiedade/induzido quimicamente , Masculino , Pirenos/toxicidade , Feminino , Camundongos , Comportamento Animal/efeitos dos fármacos , Testosterona/sangue , EstradiolRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Sarcococca hookeriana var. digyna Franch. has been widely utilized in folk medicine by the Miao people in the southwestern region of China for treating skin sores which may be associated with microbial infection. AIM OF THE STUDY: To investigate the antifungal bioactivity of S. hookeriana var. digyna against fluconazole-resistant Candida albicans in vitro and in vivo, as well as its underlying mechanism and the key bioactive component. MATERIALS AND METHODS: The antifungal bioactivity of 80% ethanol extract of S. hookeriana var. digyna (SHE80) was investigated in vitro using the broth microdilution method, time-growth curve, and time-kill assay. Its key functional component and antifungal mechanism were explored with combined approaches including UPLC-Q-TOF-MS, network pharmacology and metabolomics. The antifungal pathway was further supported via microscopic observation of fungal cell morphology and examination of its effects on fungal biofilm and cell membranes using fluorescent staining reagents. In vivo assessment of antifungal bioactivity was conducted using a mouse model infected with C. albicans on the skin. RESULTS: S. hookeriana var. digyna suppressed fluconazole-resistant C. albicans efficiently (MIC = 16 µg/mL, MFC = 64 µg/mL). It removed fungal biofilm, increased cell membrane permeability, induced protein leakage, reduced membrane fluidity, disrupted mitochondrial membrane potential, induced the release of reactive oxygen species, promoted cell apoptosis, and inhibited the transformation of fungi from the yeast state to the hyphal state significantly. In terms of mechanism, it affected sphingolipid metabolism and signaling pathway. Moreover, the predicted bioactive component, sarcovagine D, was supported by antifungal bioactivity evaluation in vitro (MIC = 4 µg/mL, MFC = 16 µg/mL). Furthermore, S. hookeriana var. digyna promoted wound healing, reduced the number of colony-forming units, and reduced inflammation effectively in vivo. CONCLUSIONS: The traditional use of S. hookeriana var. digyna for fungal skin infections was supported by antifungal bioactivity investigated in vitro and in vivo. Its mechanism and bioactive component were predicted and confirmed by experiments, which also provided a new antifungal agent for future research.
Assuntos
Antifúngicos , Biofilmes , Candida albicans , Farmacorresistência Fúngica , Fluconazol , Testes de Sensibilidade Microbiana , Extratos Vegetais , Antifúngicos/farmacologia , Antifúngicos/isolamento & purificação , Candida albicans/efeitos dos fármacos , Animais , Fluconazol/farmacologia , Farmacorresistência Fúngica/efeitos dos fármacos , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Camundongos , Biofilmes/efeitos dos fármacos , Candidíase/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismo , Feminino , Potencial da Membrana Mitocondrial/efeitos dos fármacosRESUMO
Zanthoxylum motuoense (Tibetan prickly ash, MTHJ), different from the Chinese prickly ash species, is distributed only in the Tibet. Now the chemical characterization and antibacterial activity of MTHJ extracts were analyzed for the first time. As a result, Schinifoline (12), γ-Fagarine (8), (2E,7E,9E)-6 S-Hydroxy-N-(2-methylpropyl)-11-oxo-2, 7, 9-Dodecatrienamide (6), and Neoechinulin A (17) were found to be the major different factors by untarget LC-MS metabolomics together with quantitative analysis on target. These four compounds were also the major antibacterial constituents. Then, the antimicrobial activity of MTHJ fractions was evaluated with colony forming units (CFU), fluorescence microscopy imaging, SEM and investigating the potential food preservation. Nutritional composition, colour and sensory evaluation of extract-treated samples were evaluated along storage time. The results suggested the MTHJ may be used for meat products preservation, and the scores were significantly higher for its unique flavor, which offered a promising choice for food safety, preservation and reducing foodborne illness.
RESUMO
The abuse of antibiotics leads to the rapid spread of bacterial resistance, which seriously threatens human life and health. Now, 8 resorcylic acid derivatives, including 4 new compounds (1-4) were isolated from Lysimachia tengyuehensis by bio-guided isolation, and they inhibited both methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) (MIC = 4-8 µg/mL). Notably, 1 and 2 rapidly killed MRSA and VRE within 40 min without drug resistance in 20 days. Mechanically, they potently disrupted biofilm and cell membrane by interfering with bacterial metabolic imbalance. The structure-activity relationship (SAR) revealed that the lipophilic long carbon chains (C-5/C-6) and hydrophilic hydroxyl/carboxyl groups were essential for the anti-MRSA and VRE bioactivity. Additionally, they effectively recovered MRSA-infected skin wounds and VRE-infected peritoneal in vivo. Resorcylic acid derivatives showed significant anti-MRSA and VRE bioactivity in vitro and in vivo with potential application for the first time.
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Autism spectrum disorder (ASD) is a neurodevelopmental disorder, characterized by social communication disability and stereotypic behavior. This study aims to investigate the impact of prenatal exposure to 1-nitropyrene (1-NP), a key component of motor vehicle exhaust, on autism-like behaviors in a mouse model. Three-chamber test finds that prenatal 1-NP exposure causes autism-like behaviors during the weaning period. Patch clamp shows that inhibitory synaptic transmission is reduced in medial prefrontal cortex of 1-NP-exposed weaning pups. Immunofluorescence finds that prenatal 1-NP exposure reduces the number of prefrontal glutamate decarboxylase 67 (GAD67) positive interneurons in fetuses and weaning pups. Moreover, prenatal 1-NP exposure retards tangential migration of GAD67-positive interneurons and downregulates interneuron migration-related genes, such as Nrg1, Erbb4, and Sema3F, in fetal forebrain. Mechanistically, prenatal 1-NP exposure reduces hydroxymethylation of interneuron migration-related genes through inhibiting ten-eleven translocation (TET) activity in fetal forebrain. Supplement with alpha-ketoglutarate (α-KG), a cofactor of TET enzyme, reverses 1-NP-induced hypohydroxymethylation at specific sites of interneuron migration-related genes. Moreover, α-KG supplement alleviates 1-NP-induced migration retardation of interneurons in fetal forebrain. Finally, maternal α-KG supplement improves 1-NP-induced autism-like behaviors in weaning offspring. In conclusion, prenatal 1-NP exposure causes autism-like behavior partially by altering DNA hydroxymethylation of interneuron migration-related genes in developing brain.
Assuntos
Encéfalo , Modelos Animais de Doenças , Efeitos Tardios da Exposição Pré-Natal , Animais , Camundongos , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Efeitos Tardios da Exposição Pré-Natal/genética , Feminino , Gravidez , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Transtorno Autístico/genética , Transtorno Autístico/induzido quimicamente , Transtorno Autístico/metabolismo , Metilação de DNA/efeitos dos fármacos , Metilação de DNA/genética , Comportamento Animal/efeitos dos fármacos , Masculino , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/induzido quimicamente , Transtorno do Espectro Autista/metabolismo , Pirenos/toxicidade , Camundongos Endogâmicos C57BLRESUMO
Methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE) cause more than 100,000 deaths each year, which need efficient and non-resistant antibacterial agents. SAR analysis of 162 flavonoids from the plant in this paper suggested that lipophilic group at C-3 was crucial, and then 63 novel flavonoid derivatives were designed and total synthesized. Among them, the most promising K15 displayed potent bactericidal activity against clinically isolated MRSA and VRE (MICs = 0.25-1.00 µg/mL) with low toxicity and high membrane selectivity. Moreover, mechanism insights revealed that K15 avoided resistance by disrupting biofilm and targeting the membrane, while vancomycin caused 256 times resistance against MRSA, and ampicillin caused 16 times resistance against VRE by the same 20 generations inducing. K15 eliminated residual bacteria in mice skin MRSA-infected model (>99 %) and abdominal VRE-infected model (>92 %), which was superior to vancomycin and ampicillin.
Assuntos
Antibacterianos , Flavonoides , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana , Enterococos Resistentes à Vancomicina , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Flavonoides/farmacologia , Flavonoides/química , Flavonoides/síntese química , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Enterococos Resistentes à Vancomicina/efeitos dos fármacos , Animais , Camundongos , Relação Estrutura-Atividade , Estrutura Molecular , Relação Dose-Resposta a Droga , Infecções Estafilocócicas/tratamento farmacológico , HumanosRESUMO
A polar homochiral 3D MOF [{Co2(L)(bpe)(H2O)}·5H2O]n constructed with cobalt(II) and a new ligand N-(1,3-dicarboxy-5-benzyl)-carboxymethylglycine (H4L) accommodates ordered helical water streams in its helical grooves. It provides the first example of switchable ferroelectric and optical behavior through two-step reversible single-crystal to single-crystal transformation (SCSC) upon desorption/adsorption of water spirals and coordinated water molecules, respectively.
Assuntos
Compostos Organometálicos/química , Água/química , Adsorção , Cobalto/química , Modelos Moleculares , Teoria Quântica , Propriedades de SuperfícieRESUMO
Two unique windmill-like aziridine-containing indole alkaloids, possessing an unprecedented 6/5/5/6/6/5/3 rigid ring system and an unusual azabicyclo[3.1.0]hexane core, were isolated from Alstonia scholaris. Their structures were established by spectroscopy, X-ray diffraction, and electronic circular dichroism calculations. The novel compounds exhibited significant anti-inflammatory bioactivity in vitro and alleviated LPS-induced acute lung injury in mice.
Assuntos
Alstonia , Plantas Medicinais , Camundongos , Animais , Alstonia/química , Alcaloides Indólicos , Anti-Inflamatórios , Difração de Raios X , Estrutura Molecular , Folhas de Planta/químicaRESUMO
A phytochemical investigation of the whole plants of T. delavayi led to the isolation of five new dimeric benzylisoquinoline alkaloids, thalidelavines A-E (1-5), together with six known congeners (6-11). The structures and absolute configurations of new compounds were established based on analyses of spectroscopic data, ECD calculations, and single crystal X-ray crystallography. Thalidelavines A-E (1-5) were structurally complex bisbenzylisoquinoline alkaloids with various configurations. These isolated alkaloids were evaluated for their cytotoxic and immunosuppressive effects. Among them, both 9 and 10 displayed significant cytotoxicities against T98G cell lines with an IC50 value of 2.1 µM, compared with the positive CPT-11 (IC50 = 3.0 µM). In addition, 5-7 showed remarkable immunosuppressive effects. These findings not only enrich the structural diversity of bisbenzylisoquinoline alkaloids, but also provide potential candidates for the further development of the antitumor and immunosuppressive agents.
Assuntos
Alcaloides , Benzilisoquinolinas , Thalictrum , Benzilisoquinolinas/farmacologia , Benzilisoquinolinas/química , Thalictrum/química , Estrutura Molecular , Alcaloides/farmacologia , Alcaloides/química , Compostos Fitoquímicos/farmacologiaRESUMO
Three new steroidal alkaloids, veratrasines A - C (1-3), along with ten known analogues (4-13) were isolated from the roots of Veratrum stenophyllum. Their structures were elucidated by NMR and HRESIMS data and comparison with the reported data in the literatures. A plausible biosynthetic pathway for 1 and 2 were proposed. Compounds 1, 3, and 8 showed moderate cytotoxic activity against MHCC97H and H1299 cell lines.
Assuntos
Alcaloides , Veratrum , Veratrum/química , Estrutura Molecular , Raízes de Plantas , Esteroides , Alcaloides de Veratrum/químicaRESUMO
Background: HIV self-testing (HIVST) offers potential solutions to challenges associated with site-based HIV testing (SBHT). However, the effectiveness of HIVST as an HIV prevention strategy for men who have sex with men (MSM) discontinuing pre-exposure prophylaxis (PrEP) after the completion of PrEP demonstration project has rarely been assessed. Methods: The China Real-world Study of Oral PrEP (CROPrEP) project was conducted in four cities in China. Participants were directed to community resources to continue their PrEP medication after the discontinuation of project-provided PrEP at the last CROPrEP visit. We conducted a multicentre open-label randomized controlled trial among MSM who had discontinued PrEP induced by the completion of CROPrEP. Eligible participants were randomly assigned to either the intervention group or the control group (1:1). Participants received regular health education and behavioural interventions throughout the trial. The intervention group was given a link to order free HIVST kits online, while the control group received information about free SBHT. Both groups completed internet-based follow-up surveys at three and six months. The primary outcome was the proportion of participants who underwent HIV testing during the six-month follow-up period. This trial was registered at chictr.org.cn (ChiCTR2000038416). Findings: Between November 2020 and January 2021, we recruited a total of 620 participants (300 in the intervention group and 320 in the control group). The follow-up completion rates were 99·0% and 95·0% in the intervention and control groups, respectively. At baseline, the median age of participants was 32 (interquartile range: 26-37), and 77·7% underwent HIV testing in the past three months. The proportion of participants who underwent HIV testing in the past three months was higher in the intervention group than in the control group at both the three-month (adjusted risk difference [RD]: 36·7, 95% confidence interval [CI]: 35·1-38·5, p < 0·001) and six-month (RD: 26·7, 95% CI: 24·6-28·7 p < 0·001) follow-up periods. Interpretation: Our study suggests that providing online distribution of HIVST kits for MSM with PrEP discontinuation induced by completion of the PrEP project effectively promoted HIV testing. This digital approach improves access to HIV testing for MSM and can be applicable to other settings where MSM turn to online public health services. Funding: The study was funded by the Fund of National Natural Science Foundation of China; the Mega-Projects of National Science Research for the 13th Five-Year Plan; and the Liaoning Revitalization Talents Program, China.
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Veratrazine A (1), a steroidal alkaloid with a unique 6/5/5 triheterocyclic scaffold as the side chain, was isolated from Veratrum stenophyllum, and its structure was established via spectroscopic analyses and X-ray diffraction. A plausible biosynthetic pathway for 1 is proposed. Bioassy exhibits moderate anti-inflammatory activities in vitro and in vivo.