The spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contains a cleavage motif R-X-X-R for furin-like enzymes at the boundary of the S1/S2 subunits. The cleavage of the site by cellular proteases is essential for S protein activation and virus entry. We screened the inhibitory effects of crude drugs on in vitro furin-like enzymatic activities using a fluorogenic substrate with whole-cell lysates. Of the 124 crude drugs listed in the Japanese Pharmacopeia, aqueous ethanolic extract of Cnidii Monnieris Fructus, which is the dried fruit of Cnidium monnieri Cussion, significantly inhibited the furin-like enzymatic activities. We further fractionated the plant extract and isolated the two active compounds with the inhibitory activity, namely, imperatorin and osthole, whose IC 50 values were 1.45 mM and 9.45 µM, respectively. Our results indicated that Cnidii Monnieris Fructus might exert inhibitory effects on furin-like enzymatic activities, and that imperatorin and osthole of the crude drug could be potential inhibitors of the motif cleavage.

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The identification of accidental allergen contamination in processed foods is crucial for risk management strategies in the food processing industry to effectively prevent food allergy incidents. Here, we propose a newly designed passive stop valve with high pressure resistance performance termed an “air plug-in valve” to further improve microfluidic devices for the detection of target nucleic acids. By implementing the air plug-in valve as a permanent stop valve, a maximal allowable flow rate of 70 µL/min could be achieved for sequential liquid dispensing into an array of 10 microchambers, which is 14 times higher than that achieved with the previous valve arrangement using single-faced stop valves. Additionally, we demonstrate the simultaneous detection of multiple food allergens (wheat, buckwheat, and peanut) based on the colorimetric loop-mediated isothermal amplification assay using our diagnostic device with 10 microchambers compactly arranged in a 20-mm-diameter circle. After running the assays at 60 °C for 60 min, any combination of the three types of food allergens and tea plant, which were used as positive and negative control samples, respectively, yielded correct test results, without any cross-contamination among the microchambers. Thus, our diagnostic device will provide a rapid and easy sample-to-answer platform for ensuring food safety and security.

The identification of accidental allergen contamination in processed foods is crucial for risk management strategies in the food processing industry to effectively prevent food allergy incidents. Here, we propose a newly designed valve configuration termed an “air plug-in valve” to further improve microfluidic devices capable of multiplexed detection of targeted nucleic acids in a single operation. By implementing the air plug-in valve as a permanent stop valve, a maximal allowable flow rate of 70 µL/min could be achieved for sequential liquid dispensing into an array of 10 microchambers, which is 14 times higher than that achieved with the previous valve arrangement using single-faced stop valves. Additionally, we demonstrate the simultaneous detection of multiple food allergens (wheat, buckwheat, and peanut) based on the colorimetric loop-mediated isothermal amplification assay using our diagnostic device with 10 microchambers compactly arranged in a 20-mm-diameter circle. After running the assays at 60°C for 60 min, any combination of the three types of food allergens and tea plant, which were used as positive and negative control samples, respectively, yielded correct test results, without any cross-contamination among the microchambers. Thus, our diagnostic device will provide a rapid and easy sample-to-answer platform for ensuring food safety and security.

A new γ-butenolide glycoside, named styphnoloside A (1), was isolated from the root of Styphnolobium japonicum (L.) Schott (= Sophora japonica L.), together with saikoisoflavonoside A (2) and sophoraside A (3). The structure of 1 was characterized as puerol B 2"-O-neohesperidoside based on oneand two-dimensional (1D and 2D) NMR, MS, and electronic circular dichroism (ECD) spectral data. The absolute configuration of the aglycone moiety of 1 was assigned by comparing its experimental ECD spectrum with the calculated ECD spectrum.Styphnolobium japonicum (L.) Schott (= Sophora japonica L.) is a deciduous tree belonging to the Leguminosae family and is native to China. The bud, fruit and root are used in crude drugs known as "huai-gen" in Chinese. The dried flowers of S. japonicum are used in traditional Japanese medicine for anti-hemorrhagic, anti-hemostatic, and analgesic effects. 1,2 There have been few phytochemical investigations of the root of S. japonicum to date aside from our previously reported isolation and structural elucidation of several flavonoids 3,4 and butenolides. 5,6 In the current paper, we report the isolation, purification, and structure elucidation of a new γ-butenolide glycoside, styphnoloside A (1), together with two known compounds, saikoisoflavonoside A 7 (2) and sophoraside A 5,6 (3), from the root this plant.The roots were dried, extracted with methanol (MeOH) under reflux, and the organic solvent was removed by vacuum evaporation. The combined MeOH extract was suspended in water and partitioned with diethyl ether (Et2O), ethyl acetate (EtOAc) and n-butanol (n-BuOH) successively to yield the corresponding soluble layers. The n-BuOH soluble portion was separated by octadecyl-silyl (ODS) column chromatography into 16 fractions (Fr. 1 to 16). Fr. 2 was further subjected to ODS column