This article was aimed to study the chemical constituents of Dioscorea opposita Thunb.The chemical constituents were isolated and purified by Diaion HP-20,Toyopearl HW-40,Sephadex LH-20,MCI Gel CHP-20,silica gel column chromatography and preparative HPLC,TLC,purification and isolation from Dioscorea opposita Thunb.The structures of isolated compounds were identified by thc physicochemical properties and spectral analysis.The result showed that 14 compounds were isolated from Dioscorea opposita Thunb.The chemical structures were elucidated as L-Tryptophane (1),Seguinosides F (2),1-methoxycarbonyl-β-carboline (3),Helichrysin A (4),Bungein A (5),Hydroquinone (6),Zarzissine (7),Cyclo-(Pro-Thr) (8),4-Hydroxy-3-methoxybenzyl alcohol (9),pyridine-3-carboxamide (10),Arbutin (11),Methyl syringate 4-O-β-D-glucopyranoside (12),L-Phenylalanine (13),1,2-benzenedicarboxylic acid,1,2-bis[2-(2-hydroxyethoxy) ethyl] ester (14).It was concluded that chemical compounds 1-14 were isolated for the first time from Dioscorea opposita Thunb.

AIM: To investigate the differences in varying stages of non-proliferative diabetic retinopathy(NPDR)using optical coherence tomography angiography(OCTA).METHODS: Cross-sectional study. A total of 77 cases(77 eyes)of diabetic patients were included, and they were divided into non-diabetic retinopathy(NDR; 23 eyes)and non-proliferative diabetic retinopathy(NPDR; 54 eyes)groups, further subdivided into mild NPDR(20 eyes), moderate NPDR(20 eyes), and severe NPDR(14 eyes). Foveal avascular zone(FAZ)area, superficial and deep capillary plexus densities(SSP and DSP), and visual acuity(LogMAR)were compared between NDR and NPDR groups. Furthermore, the visual acuity, FAZ area and levels of SSP and DSP were compared in different degrees of NPDR. Correlation analysis were conducted to elucidate relationships between FAZ area, visual acuity, SSP, DSP, and severity of the disease.RESULTS: Compared with the NDR group, the visual acuity(LogMAR)and macular FAZ area increased, while SSP and DSP were decreased in the NPDR group(P<0.05); there were significant differences in visual acuity, FAZ area and SSP and DSP levels in different degrees of NPDR(P<0.05). Visual acuity(LogMAR)and FAZ area displayed a positive correlation with the severity of disease, while SSP and DSP showed a negative correlation.CONCLUSION: With the progression of NPDR, the visual acuity(LogMAR)and FAZ area increased, and the SSP and DSP decreased.