The influence of hydrogen bonding on the structure of organic-inorganic hybrid catalysts and its application in the solvent-free epoxidation of α-olefins.

In this study, two types of catalysts were prepared by the combination of gemini quaternary ammonium salt with two distinct species of phosphotungstic acid. Catalysts prepared by the Wells-Dawson type of phosphotungstic acid and Keggin-type phosphotungstic acid both exhibited dual-phase catalytic behavior, demonstrating both heterogeneous and homogeneous catalytic activities. In comparison to the catalyst prepared by the Keggin-type phosphotungstic acid, due to the higher size of Wells-Dawson type of phosphotungstic acid, hydrogen bonding could not effectively affect the catalyst prepared by H6P2W18O62. Subsequently, the influential factors on the catalytic reaction were investigated. Through the utilization of techniques such as XPS, FT-IR, Raman spectra and other characterization methods, two distinct structure and reaction mechanisms for these catalysts were elucidated under the influence of hydrogen bonding.

Study on the epoxidation of chain olefins using biquaternary ammonium phosphotungstic acid phase transfer catalysts under no-solvent condition.

In this study, we have developed a novel catalyst synthesized by phosphotungstic acid and a gemini quaternary ammonium cation salt. This quaternary ammonium salt not only reduces the interfacial tension between olefins and hydrogen peroxide but also forms a notably stable structure with phosphotungstic acid. Dodecene was successfully epoxidized to epoxy dodecane with a selectivity of 82.9 %. The impact of initial conditions was systematically investigated such as molar ratio, temperature, reaction time, and catalyst dosage on the catalytic performance. Characterization of the catalyst morphology was performed by SEM, TEM and SAXS. Raman spectra, FT-IR and XPS spectra were employed to perform the catalyst transformation during the epoxidation reaction. This catalytic mechanism study could provide the industrial application in the epoxidation of long-chain olefins.

Molecular Regulatory Network of Anthocyanin Accumulation in Black Radish Skin as Revealed by Transcriptome and Metabonome Analysis.

To understand the coloring mechanism in black radish, the integrated metabolome and transcriptome analyses of root skin from a black recombinant inbred line (RIL 1901) and a white RIL (RIL 1911) were carried out. A total of 172 flavonoids were detected, and the analysis results revealed that there were 12 flavonoid metabolites in radish root skin, including flavonols, flavones, and anthocyanins. The relative concentrations of most flavonoids in RIL 1901 were higher than those in RIL 1911. Meanwhile, the radish root skin also contained 16 types of anthocyanins, 12 of which were cyanidin and its derivatives, and the concentration of cyanidin 3-o-glucoside was very high at different development stages of black radish. Therefore, the accumulation of cyanidin and its derivatives resulted in the black root skin of radish. In addition, a module positively related to anthocyanin accumulation and candidate genes that regulate anthocyanin synthesis was identified by the weighted gene co-expression network analysis (WGCNA). Among them, structural genes (RsCHS, RsCHI, RsDFR, and RsUGT75C1) and transcription factors (TFs) (RsTT8, RsWRKY44L, RsMYB114, and RsMYB308L) may be crucial for the anthocyanin synthesis in the root skin of black radish. The anthocyanin biosynthesis pathway in the root skin of black radish was constructed based on the expression of genes related to flavonoid and anthocyanin biosynthesis pathways (Ko00941 and Ko00942) and the relative expressions of metabolites. In conclusion, this study not only casts new light on the synthesis and accumulation of anthocyanins in the root skin of black radish but also provides a molecular basis for accelerating the cultivation of new black radish varieties.

Antidepressant actions of melatonin and melatonin receptor agonist: Focus on pathophysiology and treatment.

Depression has become one of the most commonly prevalent neuropsychiatric disorders, and the main characteristics of depression are sleep disorders and melatonin secretion disorders caused by circadian rhythm disorders. Abnormal endogenous melatonin alterations can contribute to the occurrence and development of depression. However, molecular mechanisms underlying this abnormality remain ambiguous. The present review summarizes the mechanisms underlying the antidepressant effects of melatonin, which is related to its functions in the regulation of the hypothalamic-pituitary-adrenal axis, inhibition of neuroinflammation, inhibition of oxidative stress, alleviation of autophagy, and upregulation of neurotrophic, promotion of neuroplasticity and upregulation of the levels of neurotransmitters, etc. Also, melatonin receptor agonists, such as agomelatine, ramelteon, piromelatine, tasimelteon, and GW117, have received considerable critical attention and are highly implicated in treating depression and comorbid disorders. This review focuses on melatonin and various melatonin receptor agonists in the pathophysiology and treatment of depression, aiming to provide further insight into the pathogenesis of depression and explore potential targets for novel agent development.

[Study on HPLC-fingerprint-based identification of dao-di herb and non dao-di herb of scutellariae radix].

OBJECTIVE: To compare the discrepancies between chemical constituents in Dao-di herb and non Dao-di herb of Huangqin (the root of Scutellaria baicalensis), study the impact of habitat and growth pattern (including cultivated and wild Huangqin) on chemical substances of Huangqin, and then provide evidence for the identification of Dao-di herb and quality evaluation of Huangqin. METHOD: The chemical constituents in Huangqin collected from different habitats and under different growth patterns, were analyzed using HPLC fingerprint. The fingerprints obtained were then evaluated by hierarchical clustering analysis, principal component analysis and components peak area pattern. RESULT: The fingerprints' chemical profiles of Dao-di herb and non Dao-di Huangqin had significant disparity. The fingerprints of modem Dao-di herb Huangqin samples originated from Chengde (Hebei Province) were significantly different from those from other habitats, though the fingerprints of the non Dao-di Huangqin collected from Chifeng (Inner Mongolia) and Chengde had high similarity to each other. The chemical characteristics of Huangqin samples collected from the habitats recorded in ancient herbals, such as Qingyang (Gansu Province), Yan'an (Shaanxi Province), Linyi (Shangdong Province), Changzhi and Jinzhong (Shanxi Province) were similar. The fingerprints of modern non Dao-di samples collected from Dingxi and Longnan (Gansu Province) and Shangluo (Shaanxi Province) had high similarity. In addition, the content of acteoside in wild Huangqin was higher than that in cultivated Huangqin. CONCLUSION: Dao-di herb and non Dao-di herb of Huangqin could be distinguished using the developed HPLC fingerprints. The results obtained may provide evidence for the quality control and pharmcodynamical research of Dao-di herb and non Dao-di Huangqin.