[Optimization of ethanol reflux extraction process of Ziziphi Spinosae Semen- Schisandrae Sphenantherae Fructus based on network pharmacology combined with response surface methodology].

The present study optimized the ethanol extraction process of Ziziphi Spinosae Semen-Schisandrae Sphenantherae Fructus drug pair by network pharmacology and Box-Behnken method. Network pharmacology and molecular docking were used to screen out and verify the potential active components of Ziziphi Spinosae Semen-Schisandrae Sphenantherae Fructus, and the process evaluation indexes were determined in light of the components of the content determination under Ziziphi Spinosae Semen and Schisandrae Sphenantherae Fructus in the Chinese Pharmacopoeia(2020 edition). The analytic hierarchy process(AHP) was used to determine the weight coefficient of each component, and the comprehensive score was calculated as the process evaluation index. The ethanol extraction process of Ziziphi Spinosae Semen-Schisandrae Sphenantherae Fructus was optimized by the Box-Behnken method. The core components of the Ziziphi Spinosae Semen-Schisandrae Sphenantherae Fructus drug pair were screened out as spinosin, jujuboside A, jujuboside B, schisandrin, schisandrol, schisandrin A, and schisandrin B. The optimal extraction conditions obtained by using the Box-Behnken method were listed below: extraction time of 90 min, ethanol volume fraction of 85%, and two times of extraction. Through network pharmacology and molecular docking, the process evaluation indexes were determined, and the optimized process was stable, which could provide an experimental basis for the production of preparations containing Ziziphi Spinosae Semen-Schisandrae Sphenantherae Fructus.

Melanoleuca subgriseoflava and M. substridula-two new Melanoleuca species (Agaricales, Basidiomycota) described from China.

Two new Melanoleuca species, Melanoleuca subgriseoflava and M. substridula, are originally reported and described in China based on both morphological and molecular methods. Melanoleuca subgriseoflava, collected in Liaoning province, is mainly characterized by its greyish-brown to yellowish-grey pileus, creamy to light orange lamellae, greyish-yellow context, round and warted basidiospores and fusiform hymenial cystidia. Melanoleuca substridula, discovered in Sichuan province, is mainly characterized by its light brown to dark brown pileus, whitish lamellae, light brown to greyish-brown stipe, round and warted basidiospores and lack of any forms of cystidia. The phylogenetic relationships as well as divergence-time estimation were analyzed using the combined data set (ITS-nrLSU-RPB2), and the results showed that the two Melanoleuca species formed two distinct lineages. Based on the combination of morphological and molecular data, M. subgriseoflava and M. substridula are confirmed as two new species to science. A theoretical basis is provided for the species diversity of Melanoleuca.

A pH-applicative fluorescent probe with long measuring range for monitoring hydrazine in water samples and Arabidopsis thaliana.

In this work, a fluorescent probe, RhodCl-Hz, with pH-applicative capability and long measuring range, was developed to serve the topic on the enrichment process of hydrazine. It was practical due to the clear acid-base boundary and the sectioned linear ranges. With the excitation wavelength of 515 nm and the emission peak at 565 nm, the detecting system was steady. It exhibited a clear cut-off point at pH 7.0 and steady fluorescence signals within the range of 7.0-10.0. As a whole, the linear range of 10.0-500 µM (1.0-50.0 equivalent) was long. The Limit of Detection value was calculated as 0.64 µM. With high selectivity, RhodCl-Hz was applied to suit water samples and biological imaging in both Arabidopsis Thaliana root tips and living MCF-7 cells. The information here might be helpful for revealing the enrichment process of hydrazine.

MicroRNA-Triggered Deconstruction of Field-Free Spherical Nucleic Acid as an Electrochemiluminescence Biosensing Switch.

Herein, a new field-free and highly ordered spherical nucleic acid (SNA) nanostructure was self-assembled directly by ferrocene (Fc)-labeled DNA tweezers and DNA linkers based on the Watson-Crick base pairing rule, which was employed as an electrochemiluminescence (ECL) quenching switch with improved recognition efficiency due to the high local concentration of the ordered nanostructure. Moreover, with a collaborative strategy combined with the advantages of both self-accelerated approach and pore confinement-enhanced ECL effect, the mesoporous silica nanospheres (mSiO2 NSs) were prepared to be filled with rubrene (Rub) as ECL emitters and Pt nanoparticles (PtNPs) as coreaction accelerators (Rub-Pt@mSiO2 NSs), which demonstrated high ECL response in the aqueous media (dissolved O2 as coreactant). When the SNA nanostructure was immobilized on the Rub-Pt@mSiO2 NSs-modified electrode, it presented a "signal off" state owing to the quenching effect of the Fc molecules. As a proof of concept, the SNA-based ECL switch platform was applied in the detection of microRNA let-7b (let-7b). Impressively, in the presence of the target let-7b, a deconstruction of the SNA nanostructure was actuated, causing the Fc to leave the electrode surface and achieved an extremely high ECL recovery ("signal on" state). Hence, a sensitive determination for let-7b was realized with a low detection limit of 1.8 aM ranging from 10 aM to 1 nM by employing the Rub-Pt@mSiO2 NSs-based ECL platform combined with the target-triggered SNA deconstruction, which also offered an ingenious method for the further applications of biomarker analyses.

In Vitro Evaluation of the Antibacterial Properties of Tea Tree Oil on Planktonic and Biofilm-Forming Streptococcus mutans.

Streptococcus mutans (S. mutans) is the principal etiologic agent in the occurrence of human dental caries and the formation of biofilms on the surface of teeth. Tea tree oil (TTO) has been demonstrated to exhibit a wide range of pharmacological actions that can effectively inhibit the activity of bacteria. In this context, we evaluated the in vitro antimicrobial effects of TTO on S. mutans both during planktonic growth and in biofilms compared with 0.2% CHX. We determined the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) using the microdilution method, the bacteriostatic rate using an MTT assay, and the antimicrobial time using a time-kill assay. Then, we explored the effects of TTO on acid production and cell integrity. Furthermore, the effects of TTO on the biomass and bacterial activity of S. mutans biofilms were studied. Finally, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were used to investigate the structure and activity of biofilms. The MIC and MBC values were 0.125% and 0.25%, and the bacterial inhibition rate was concentration dependent. TTO can effectively inhibit bacterial acid production and destroy the integrity of the cell membrane. Electron micrographs revealed a reduction in bacterial aggregation, inhibited biofilm formation, and reduced biofilm thickness. The effect of TTO was the same as that of 0.2% CHX at a specific concentration. In summary, we suggest that TTO is a potential anticariogenic agent that can be used against S. mutans.