RESUMO
Seco-sativene sesquiterpenoids are an important member of phytotoxins and plant growth regulators isolated from a narrow spectrum of fungi. In this report, eight seco-sativene sesquiterpenoids (1-8) were first analyzed using the UPLC-Q-TOF-MS/MS technique in positive mode, from which their mass fragmentation pathways were suggested. McLafferty rearrangement, 1,3-rearrangement, and neutral losses were considered to be the main fragmentation patterns for the [M+1]+ ions of 1-8. According to the structural features (of different substitutes at C-1, C-2, and C-13) in compounds 1-8, five subtypes (A-E) of seco-sativene were suggested, from which subtypes A, B/D, and E possessed the diagnostic daughter ions at m/z 175, 189, and 203, respectively, whereas subtype C had the characteristic daughter ion at m/z 187 in the UPLC-Q-TOF-MS/MS profiles. Based on the fragmentation patterns of 1-8, several known compounds (1-8) and two new analogues (9 and 10) were detected in the extract of plant pathogen fungus Bipolaris sorokiniana based on UPLC-Q-TOF-MS/MS analysis, of which 1, 2, 9, and 10 were then isolated and elucidated by NMR spectra. The UPLC-Q-TOF-MS/MS spectra of these two new compounds (9 and 10) were consistent with the fragmentation mechanisms of 1-8. Compound 1 displayed moderate antioxidant activities with IC50 of 0.90 and 1.97 mM for DPPH and ABTS+ scavenging capacity, respectively. The results demonstrated that seco-sativene sesquiterpenoids with the same subtypes possessed the same diagnostic daughter ions in the UPLC-Q-TOF-MS/MS profiles, which could contribute to structural characterization of seco-sativene sesquiterpenoids. Our results also further supported that UPLC-Q-TOF-MS/MS is a powerful and sensitive tool for dereplication and detection of new analogues from crude extracts of different biological origins.
RESUMO
BACKGROUND: Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death worldwide, and has relatively high recurrence rates. Few studies have been published on the clinical stages of recurrent HCC. AIM: To assess the applicability of the Barcelona Clinic Liver Cancer (BCLC) staging for recurrent HCC and the need to establish clinical stage criteria for recurrent HCC. METHODS: The clinicopathological data of 81 patients with recurrent HCC who were admitted to the Hospital of Guangxi Zhuang Autonomous Region from January 2013 to December 2017 were collected. The patients were divided into three groups according to the BCLC staging system as follows: (1) Group A with BCLC stage A, 51 patients; (2) Group B with BCLC stage B, 14 patients; and (3) Group C with BCLC stage C, 16 patients. The median time to tumor recurrence and the median overall survival were compared. RESULTS: The median time to tumor recurrence in groups A, B, and C was 16 ± 1.5 mo, 10 ± 2.8 mo, and 6 ± 0.5 mo, respectively, with a statistically significant difference among them (χ 2 = 70.144, P < 0.05); no statistically significant difference was noted between group A and group B (χ 2 = 2.659, P > 0.05), although there were statistically significant differences between group A and group C and between group B and group C (χ 2 = 62.110, and 19.972, P < 0.05). The median overall survival in groups A, B, and C were 42 ± 5.1 mo, 22 ± 3.1 mo, and 13 ± 1.8 mo, respectively, with a statistically significant difference among them (χ 2 = 38.949, P < 0.05); there were statistically significant differences between group A and group B, group A and group C, and group B and group C (χ 2 = 9.577, 37.172, and 7.183, respectively; P < 0.05). CONCLUSION: There are different prognoses in recurrent HCC patients according to the BCLC staging. Therefore, BCLC staging is applicable to recurrent HCC and it is essential to formulate clinical stage criteria for recurrent HCC.
