Synthesis, Structural Characterization, and Biological Activities of 1,3,4- Thiadiazole Derivatives Containing Sulfonylpiperazine Structures.

To develop novel bacterial biofilm inhibiting agents, a series of 1,3,4-thiadiazole derivatives containing sulfonylpiperazine structures were designed, synthesized, and characterized using 1H nuclear magnetic resonance (1H NMR), 13C nuclear magnetic resonance (13C NMR), and high-resolution mass spectrometry. Meanwhile, their biological activities were evaluated, and the ensuing structure-activity relationships were discussed. The bioassay results showed the substantial antimicrobial efficacy exhibited by most of the compounds. Among them, compound A24 demonstrated a strong efficacy with an EC50 value of 7.8 µg/mL in vitro against the Xanthomonas oryzae pv. oryzicola (Xoc) pathogen, surpassing commercial agents thiodiazole copper (31.8 µg/mL) and bismerthiazol (43.3 µg/mL). Mechanistic investigations into its anti-Xoc properties revealed that compound A24 operates by increasing the permeability of bacterial cell membranes, inhibiting biofilm formation and cell motility, and inducing morphological changes in bacterial cells. Importantly, in vivo tests showed its excellent protective and curative effects on rice bacterial leaf streak. Besides, molecular docking showed that the hydrophobic effect and hydrogen-bond interactions are key factors between the binding of A24 and AvrRxo1-ORF1. Therefore, these results suggest the utilization of 1,3,4-thiadiazole derivatives containing sulfonylpiperazine structures as a bacterial biofilm inhibiting agent, warranting further exploration in the realm of agrochemical development.

Screening of a potential leafhopper attractants and their applications in tea plantations.

Pheromones can be used as leafhopper attractants. However, commercial pheromone products, such as the Ingle lure, have certain limitations, including poor persistence in the field. In this study, (E)-2-hexenal, (Z)-3-hexen-1-ol, (Z)-3-hexenyl acetate, (E)-ocimene, linalool, and geraniol were selected and behaviorally tested as potential leafhopper attractants. Y-tube olfactometer tests showed that the C2 formulation was more effective than other formulations. In tea field trials, the number of leafhoppers caught by sticky board traps baited with C2 lures was greater than that caught by treatment. The number of leafhoppers attracted by the C2 lures was greater than that attracted by the commercial Ingle lures. Additionally, the total amount of active C2 components on lures was greater than that of the active components on the lure after 14 days. Thus, the results indicated that the C2 formulation may attract leafhoppers and have a greater persistence than other formulations in tea field.

SATB2-Associated Syndrome: a Case Report of a De Novo Nonsense Mutation in SATB2 from China and Review of Literature.

BACKGROUND: To study the clinical and genetic features from a Chinese child with SATB2-associated syndrome (SAS) and review of literature. METHODS: The girl, 2 years 3 months old, is admitted to the Department of Pediatric Rehabilitation in our hospital. This patient has mental retardation, language development disorder, cleft palate II0, micrognathia, malocclusion, irritability and bilateral oblique palpebral fissure as a clinical manifestation and is treated for 3 months. RESULTS: Gesell Development Scale (GDS) evaluation displays the patient's action capacity: gross motor 13.4, DQ 41%; fine motor 14.1, DQ 44%; adaptive behavior: DA 15.2, DQ 47%; speech capacity: DA 8.8; DQ 27%; person capacity: DA 11.7, DQ, 36%. Bayley Scale evaluation displays MDI < 50 and PDI < 50. Sleep EEG showed bilateral frontal pole - frontal - central - anterior temporal area presents in sharp wave, sharp and slow wave synchronization issue. A brain MRI showed that signal T2 is strengthened in the internal capsule hind leg. Flake T2FLATR high signal can been showed in the periventricular area of the parietal lobe in bilateral hemisphere. Molecular studies showed the patient carries a de novo nonsense mutation c.1285G>A (p.R429X) in SATB2. CONCLUSIONS: SATB2 mutation is not detected in the parents of the subjects. This study is important to further study the clinical features of SATB2-associated syndrome and to enlarge the SATB2 mutation spectrum.

Predictive Value of Neurodevelopmental Outcome and Serum Tau Protein Level in Neonates with Hypoxic Ischemic Encephalopathy.

BACKGROUND: Tau protein is s specific protein expressed by neurons in the central nervous system. Elevated serum Tau protein is associated with many diseases of the central nervous system. The serum Tau protein level in neonates with hypoxic ischemic encephalopathy (HIE) is still poorly understood. METHODS: Forty-one human neonates with HIE and thirty-five healthy neonates (control group) within 24 hours after birth were studied. Tau protein in serum was detected by enzyme-linked immunosorbent assay. Neurological outcome was assessed at 9 months of age according to the Gesell developmental scale. RESULTS: Tau protein in serum was significantly higher in the HIE group than in the control group (p < 0.01), in neonates with severe HIE than neonates with moderate HIE (p < 0.01), and in infants with neurodevelopmental retardation compared with those with normal neurodevelopment (p < 0.01). The result of this study showed an obvious negative correlation between the serum Tau protein level and development quotients of neonates with HIE (rs = -0.6172, p < 0.01). Receiver operator characteristic curve analysis showed that Tau protein (cutoff value 933.04 pg/mL) was a predictor of neurodevelopmental retardation outcome (AUC value = 0.860 (95% CI: 0.736 - 0.983, p < 0.01), sensitivity 100%, specificity 70.8%). CONCLUSIONS: Serum Tau protein level within 24 hours after birth can be used as a marker for the early diagnosis of neonatal HIE and predicting neurodevelopmental outcomes.

Oxidative N-Heterocyclic Carbene-Catalyzed γ-Carbon Addition of Enals to Imines: Mechanistic Studies and Access to Antimicrobial Compounds.

The reaction mechanism of the γ-carbon addition of enal to imine under oxidative N-heterocyclic carbene catalysis is studied experimentally. The oxidation, γ-carbon deprotonation, and nucleophilic addition of γ-carbon to imine were found to be facile steps. The results of our study also provide highly enantioselective access to tricyclic sulfonyl amides that exhibit interesting antimicrobial activities against X. oryzae, a bacterium that causes bacterial disease in rice growing.

Antibacterial activities against rice bacterial leaf blight and tomato bacterial wilt of 2-mercapto-5-substituted-1,3,4-oxadiazole/thiadiazole derivatives.

In this study, a series of 2-mercapto-5-substituted-1,3,4-oxadiazole/thiadiazole derivatives were synthesized and evaluated for their antibacterial activities against rice bacterial leaf blight and tomato bacterial wilt caused by Xanthomonas oryzae pv. oryzae (Xoo) and Ralstonia solanacearum (R. solanacearum) via the turbidimeter test in vitro. Antibacterial bioassays indicated that most compounds demonstrated appreciable antibacterial bioactivities against Xoo and R. solanacearum. Among the title compounds, compound 4i demonstrated the best inhibitory effect against Xoo and R. solanacearum with half-maximal effective concentration (EC50) values of 14.69 and 15.14µg/mL, respectively, which were even better than those of commercial agents Bismerthiazol and Thiodiazole Copper. In vivo antibacterial activities tests under greenhouse conditions revealed that the control efficiency of compound 4i against rice bacterial leaf blight and tobacco bacterial wilt were better than those of Bismerthiazol and Thiodiazole Copper. Meanwhile, field trials also indicated that compound 4i demonstrated appreciable control efficiency against rice bacterial leaf blight and tomato bacterial wilt.

Sulfonate derivatives bearing an amide unit: design, synthesis and biological activity studies.

Pest disasters which occurs on crops is a serious problem that not only cause crop yield loss or even crop failure but can also spread a number of plant diseases.Sulfonate derivatives have been widely used in insecticide and fungicide research in recent years. On this basis, a series of sulfonate derivatives bearing an amide unit are synthesized and the biological activities are evaluated. The bioassay results showed that compounds A8, A13, A16, B1, B3, B4, B5, B10, B12 - 20, C3, C5, C9, C10, C14, C15, C17 and C19 showed 100% activity at a concentration of 500 µg/mL against the Plutella xylostella (P. xylostella). Among them, B15 which contains a thiadiazole sulfonate structure still shows 100% activity at 50 µg/mL concentration against P. xylostella and had the lowest median lethal concentration (LC50) (7.61 µg/mL) among the target compounds. Further mechanism studies are conducted on compounds with better insecticidal activity. Molecular docking results shows that B15 formed hydrophobic interactions π-π and hydrogen bonds with the indole ring of Trp532 and the carboxyl group of Asp384, respectively, with similar interaction distances or bond lengths as those of diflubenzuron. Moreover, chitinase inhibition assays are performed to further demonstrate its mode of action. In addition, the anti-bacterial activity of the series of compounds is also tested and the results showed that the series of compounds has moderate biological activity against Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas oryzae pv. oryzicola (Xoc), with inhibition rates of 91%, 92% and 92%, 88% at the concentration of 100 µg/mL, respectively. Our study indicates that B15 can be used as a novel insecticide for crop protection.

Beyond the ß-amino alcohols framework: identification of novel ß-hydroxy pyridinium salt-decorated pterostilbene derivatives as bacterial virulence factor inhibitors.

BACKGROUND: Bacterial virulence factors are involved in various biological processes and mediate persistent bacterial infections. Focusing on virulence factors of phytopathogenic bacteria is an attractive strategy and crucial direction in pesticide discovery to prevent invasive and persistent bacterial infection. Hence, discovery and development of novel agrochemicals with high activity, low-risk, and potent anti-virulence is urgently needed to control plant bacterial diseases. RESULTS: A series of novel ß-hydroxy pyridinium cation decorated pterostilbene derivatives were prepared and their antibacterial activities against Xanthomonas oryzae pv. oryzae (Xoo) were systematacially assessed. Among these pterostilbene derivatives, compound 4S exhibited the best antibacterial activity against Xoo in vitro, with an half maximal effective concentration (EC50) value of 0.28 µg mL-1. A series of biochemical assays including scanning electron microscopy, crystal violet staining, and analysis of biofilm formation, swimming motility, and related virulence factor gene expression levels demonstrated that compound 4S could function as a new anti-virulence factor inhibitor by interfering with the bacterial infection process. Furthermore, the pot experiments provided convinced evidence that compound 4S had the high control efficacy (curative activity: 71.4%, protective activity: 72.6%), and could be used to effectively manage rice bacterial leaf blight in vivo. CONCLUSION: Compounds 4S is an attractive virulence factor inhibitor with potential for application in treating plant bacterial diseases by suppressing production of several virulence factors. © 2024 Society of Chemical Industry.

Chemical constituents of Caesalpinia decapetala (Roth) Alston.

The current study targets the chemical constituents of Caesalpinia decapetala (Roth) Alston and investigates the bioactivities of the isolated compounds. Fourteen known compounds were isolated using column chromatography, and structural identification was performed by physical and spectral analyses. The biological activities of the compounds were also evaluated by 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and 2,2-diphenlyl-1-picrylhydrazyl (DPPH) assays. Emodin (6), baicalein (9), and apigenin (12) displayed antitumor activities against the MGC-803 cell line, while quercetin (2), rutin (5), baicalein (9), and epicatechin (13) showed stronger DPPH scavenging activities compared with ascorbic acid. Andrographolide (1), quercetin (2), bergenin (4), rutin (5), emodin (6), betulin (7), baicalein (9), polydatin (10), salicin (11), and apigenin (12), were obtained from C. decapetala (Roth) Alston for the first time.

Natural Products-Based Botanical Bactericides Discovery: Novel Abietic Acid Derivatives as Anti-Virulence Agents for Plant Disease Management.

The discovery of natural product-based pesticides is critical for agriculture. In this work, a series of novel tricyclic diterpenoid derivatives decorated with an amino alcohol moiety were elaborately prepared from natural abietic acid, and their antibacterial behavior was explored. Bioassay results indicated that compound C2 exhibited the most promising bioactivity (EC50 = 0.555 µg mL-1) against Xanthomonas oryzae pv. oryzae (Xoo), about 73 times higher than the effect of commercial thiodiazole copper (TC). Results of in vivo bioassays showed that compound C2 displayed significantly higher control of rice bacterial leaf blight (curative activity: 63.8%; protective activity: 58.4%) than TC (curative activity: 43.6%; protective activity: 40.8%), and their bioactivity could be improved maximally 16% by supplementing the auxiliaries. Antibacterial behavior suggested that compound C2 could suppress various virulence factors. Overall, these findings suggested that new botanical bactericide candidates could control intractable plant bacterial diseases by suppressing virulence factors.