AIM　To study the chemical constituents of Eclipta prostrata (L). METHODS　The constituents of E.prostrata were systematically separated with the Bohlmann method and percolation and hot extraction methods, and various chromatographies. The structures were elucidated by chemical and spectroscopic means. RESULTS　Ten compounds were isolated from the Eclipta prostrata. Their structures were determined as wedelolactone (1), demethylwedelolactone (2), isodemethylwedelolactone (3), α-formylterthienyl (4), strychnolactone (5), β-sitosterol (6), nonacosanol (7), stearic acid (8), lacceroic acid (9), 3,4-dihydoxy benzoic acid (10). Fourteen ocmpounds, including hydrocarbons and its esters were identified by GC-MS from the least polar fractions. CONCLUSION　Compound 3 is a new coumestan named isodemethylwedelolactone. Compounds 2-10 and compounds characterized by GC-MS analysis were obtained for the first time from Eclipta prostrata.

The heterogeneity of exhausted T cells (Tex) is a critical determinant of immune checkpoint blockade therapy efficacy. However, few studies have explored exhausted T cell subpopulations in human cancers. In the present study, we examined samples from two cohorts of 175 patients with head and neck squamous cell cancer (HNSCC) by multiplex immunohistochemistry (mIHC) to investigate two subsets of Tex, CD8⁺PD1⁺TCF1⁺ progenitor exhausted T cells (TCF1⁺Tex^prog) and CD8⁺PD1⁺TCF1^- terminally exhausted T cells (TCF1^-Tex^term). Moreover, fresh tumor samples from 34 patients with HNSCC were examined by flow cytometry and immunohistochemistry to further investigate their properties and cytotoxic capabilities and their correlation with regulatory T cells (Tregs) in the tumor immune microenvironment (TIME). mIHC and flow cytometry analysis showed that TCF1^-Tex^term represented a greater proportion of CD8⁺PD1⁺Tex than TCF1⁺Tex^prog in most patients. TCF1⁺Tex^prog produced abundant TNFα, while TCF1^-Tex^term expressed higher levels of CD103, TIM-3, CTLA-4, and TIGIT. TCF1^-Tex^term exhibited a polyfunctional TNFα⁺GZMB⁺IFNγ⁺ phenotype; and were associated with better overall survival and recurrence-free survival. The results also indicated that larger proportions of TCF1^-Tex^term were accompanied by an increase in the proportion of Tregs. Therefore, it was concluded that TCF1^-Tex^term was the major CD8⁺PD1⁺Tex subset in the HNSCC TIME and that these cells favor patient survival. A high proportion of TCF1^-Tex^term was associated with greater Treg abundance.
CD8-Positive T-Lymphocytes ; Head and Neck Neoplasms/therapy* ; Humans ; Immunotherapy/methods* ; Prognosis ; Programmed Cell Death 1 Receptor ; Squamous Cell Carcinoma of Head and Neck/therapy* ; Tumor Microenvironment ; Tumor Necrosis Factor-alpha