Mechanism of fungal inhibition activity of Nα-lauroyl-L-arginine ethyl ester (LAE) and potential in control of Penicillium expansum on postharvest citrus 'Benimadonna' (Citrus reticulata × Citrus sinensis).

Background: Citrus 'Benimadonna' (Citrus reticulata × Citrus sinensis) is a high-value perishable fruit; thus there is an urgent need for a preservation technology with high effectiveness and low safety risk from industries. Nα-Lauroyl-l-arginine ethyl ester hydrochloride (LAE) was applied to enhance preservability by compounding with natamycin, and a possible fungal inhibition mechanism based on the hypothesis of an impact on the cell membrane by surfactant was investigated.

Results: In vitro testing showed that the minimum inhibitory concentration of LAE against Penicillium expansum (PE), isolated as the predominant spoilage-inducing fungus, was 32 mg L and it was partially synergistic with natamycin.

Effects of organic nitrogen components from terrestrial input on the phytoplankton community in Jiaozhou Bay.

Dissolved organic nitrogen (DON) from terrestrial input exacerbates eutrophication and induces harmful algal blooms. We investigated the effects of hydrophilic (Hic) and low molecular weight (LMW) DON on the phytoplankton community in Jiaozhou Bay during autumn (October 2017) and spring (May 2018). Our results showed DON additions significantly increased algal growth while decreasing community biodiversity and provide a competitive advantage for Skeletonema costatum.

Influences of the hydrophilic components of two anthropogenic dissolved organic nitrogen groups on phytoplankton growth in Jiaozhou Bay, China.

Increasing human activities have caused the accumulation of dissolved organic nitrogen (DON) in the ocean, which can alter dominant coastal phytoplankton species. However, insights into DON's effects on marine phytoplankton growth are insufficient compared with those of dissolved inorganic nitrogen (DIN), especially regarding the role of specific DON components. Therefore, in this study, the effects of the hydrophilic (Hic) and low molecular weight (LMW) components of two anthropogenic DON sources on the growth and bioavailable nitrogen uptake of phytoplankton were studied using in situ cultural experiments conducted in Jiaozhou Bay, China.

Impurities preparation of sodium tanshinone IIA sulfonate by high-speed counter-current chromatography and identification by liquid chromatography/multistage tandem mass spectrometry.

Sodium Tanshinone IIA Sulfonate, the chemical modification product of Tanshinon IIA (STIIAS) is widely used in clinical treatment of angiocardiopathy, and the preparation of reference compounds of related substances for quality control is necessary. A method for separating three related substances from the bulk drug of STIIAS with high-speed counter-current chromatography (HSCCC) was developed. A solvent system composed of chloroform-n-butanol-methanol-water (17:0.