Application of Near-Infrared Spectroscopy in Determination of Schaftoside Acid in <i>Desmodium styracifolium</i>(Osb.) Merr.

The potential of Near Infrared Spectroscopy (NIRS) in quality control of Traditional Chinese Medicine has been evaluated. This study focuses on a rapid and non-destructive quantitative method for the determination of schaftoside acid content in Desmodium styracifolium by near-infrared spectroscopy. The schaftoside acid contents of 103 samples were determined by HPLC. The NIRS quantitative model of the ethanol extracts content was performed by partial least-squares (PLS) regression as linear regression with analysis values as calibration reference using 2nd derivative method as spectral preprocessing options. The model was verified by internal cross validation and external predictive validation with 22 Desmodium styracifolium samples. The correlation coefficients (r), the root-mean-square error of calibration (RMSEC), the root-mean-square error of prediction (RMSEP) and the root-mean-square error of cross-validation (RMSECV) of the calibration model for ethanol extracts content were 0.97201, 0.147, 0.162 and 0.433, respectively. The average recovery was 99.82%, and t-test showed that P > 0.5. Precision and repeatability RSD were 1.75% and 1.17%, RPD > 2.5. The data obtained from results showed that calibration model of NIRS was verified to be reliable, suggesting that the quantitative NIR models can be qualified to accurately quantify the ethanol extracts content of Desmodium styracifolium rapidly.

Schaftoside inhibits 3CL^(pro)and PL^(pro)of SARS-CoV-2 virus and regulates immune response and inflammation of host cells for the treatment of COVID-19

It is an urgent demand worldwide to control the coronavirus disease 2019(COVID-19)pandemic caused by the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)virus.The 3-chymotrypsin-like protease(3CL^(pro))and papain-like protease(PL^(pro))are key targets to discover SARS-CoV-2 inhibitors.After screening 12 Chinese herbal medicines and 125 compounds from licorice,we found that a popular natural product schaftoside inhibited 3CL^(pro)and PL^(pro)with IC_(50)values of 1.73±0.22 and 3.91±0.19μmol/L,respectively,and inhibited SARS CoV-2 virus in Vero E6 cells with EC_(50)of 11.83±3. 23μmol/L. Hydrogen-deuterium exchange mass spectrometry analysis, quantum mechanics/molecular mechanics calculations, together with site-directed mutagenesis indicated the antiviral activities of schaftoside were related with non-covalent interactions with H41, G143 and R188 of3CLpro, and K157, E167 and A246 of PLpro. Moreover, proteomics analysis and cytokine assay revealed that schaftoside also regulated immune response and inflammation of the host cells. The antiinflammatory activities of schaftoside were confirmed on lipopolysaccharide-induced acute lung injury mice. Schaftoside showed good safety and pharmacokinetic property, and could be a promising drug candidate for the prevention and treatment of COVID-19.

RP-HPLC法同时测定狭基线纹香茶菜中4个碳苷黄酮

目的建立同时定量测定狭基线纹香茶菜中viceninⅡ、isoschaftoside、schaftoside、vitexin的RH-HPLC。方法狭基线纹香茶菜70%乙醇提取液分析采用Phenomenex luna C18色谱柱（250 mm×4.6 mm,5μm）,流动相为甲醇-0.1%磷酸水溶液梯度洗脱,体积流量0.8 m L/min,检测波长344 nm;柱温为室温（25℃）。结果 ViceninⅡ、isoschaftoside、schaftoside、vitexin线性范围分别为0.38~4.18μg、0.66~7.26μg、0.43~4.73μg、0.48~5.28μg;平均回收率（n=6）分别为97.7%、98.8%、96.9%、100.1%,RSD分别为1.6%、2.1%、1.8%、1.9%。结论本法的检测波长,流动相和提取溶剂的选择在狭基线纹香茶菜中黄酮碳苷类成分的定量分析上是最适合的。

冰糖草化学成分的分离与鉴定

目的研究冰糖草(Scoparia dulcis L.)全草乙醇提取物的正丁醇萃取部位的化学成分。方法运用硅胶、Sephadex LH-20和半制备HPLC等各种方法进行分离纯化,根据理化性质和波谱数据等鉴定化合物结构。结果分离得到16个化合物,分别鉴定为(2S)-7-methoxy-2H-1,4-benzoxazin-3(4H)-one 2-O-β-glucopyranoside(1)、(2R)-7-methoxy-2H-1,4-benzoxazin-3(4H)-one 2-O-β-glucopyranoside(2)、对羟基苯甲酸甲酯(3)、对羟基苯甲醛(4)、2-唑啉酮(5)、对羟基苯乙酮(6)、薏苡素(7)、苯甲酸(8)、对羟基肉桂酸甲酯(9)、黑麦草内酯(10)、异黑麦草内酯(11)、橙酰胺乙酸酯(12)、apigenin 7-O-rutinoside(13)、hispidulin-7-O-rutinoside(14)、isoschaftoside(15)和schaftoside(16)。结论化合物1为新化合物,化合物13~16为首次从冰糖草中分离得到。