ABSTRACT
(±)-Quassidine K (1), a pair of new bis-ß-carboline alkaloid enantiomers, were isolated from Picrasma quassioides. Their structures were determined on the basis of detailed spectroscopic data analysis. The absolute configurations of (+)-S-quassidine K (1a) and (-)-R-quassidine K (1b) were determined by comparing with the reported experimental ECD spectra after chiral separation. The cytotoxicity assay showed activity against HeLa cells with IC50 values of 15.8 and 20.1 µM, respectively.
Subject(s)
Alkaloids/isolation & purification , Antineoplastic Agents/isolation & purification , Carbolines/isolation & purification , Picrasma/chemistry , Alkaloids/chemistry , Alkaloids/pharmacology , Antineoplastic Agents/pharmacology , Carbolines/chemistry , Carbolines/pharmacology , Drug Screening Assays, Antitumor , HeLa Cells , Humans , Inhibitory Concentration 50 , Molecular Structure , StereoisomerismABSTRACT
BACKGROUND: The impacts of weight loss on prognosis in nasopharyngeal carcinoma (NPC) remain unclear. The present study was therefore undertaken to investigate the association between critical weight loss and long-term survival in NPC patients. METHODS: The eligible 2399 NPC patients were reviewed. Weight change was categorized into critical weight loss (CWL) and non-critical weight loss (Non-CWL). The associations of CWL with long-term survival were analyzed by Cox regression in the entire patient and two subsets. Propensity score matching was performed to reduce the effects of confounding factors. RESULTS: CWL was defined as body weight loss of ≥4.6 %. Compared with patients without CWL, patients with CWL had significantly lower 5-year OS (72.4 vs. 79.3 %, P < 0.001), FFS (71.1 vs. 78.4 %, P <0.001), and LR-FFS (78.1 vs. 84.8 %, P <0.001), respectively. After adjustment for potential confounders, CWL remained an independence prognostic factor for OS (HR = 1.352; 95 % CI 1.160-1.576; P < 0.001), FFS (HR = 3.275; 95 % CI 1.101-9.740; P = 0.033), and LR-FFS (HR = 6.620; 95 % CI 2.990-14.658; P < 0.001), respectively. Furthermore, subgroup analysis in the cohort of patients received concurrent chemoradiotherapy or radiotherapy alone confirmed the results in the entire patient even after the propensity-score matching. In IMRT cohort, CWL was also significantly associated with a lower OS (P = 0.04) and FFS (P = 0.04). CONCLUSIONS: CWL has a significant and independent impact on long-term survival in nasopharyngeal carcinoma patients.