Structure-Based Molecular Networking for the Discovery of Anti-HBV Compounds from Saussurea lappa (Decne.) C.B Clarke.

It is a crucial to find target compounds in natural product research. This study presents a concept of structure-guided isolation to find candidate active molecules from herbs. We establish a process of anti-viral sesquiterpene networking. An analysis of the networking suggested that new anti-HBV sesquiterpene may be attributable to eudesmane-, guaiane-, cadinane-, germacane- and bisabolane-type sesquiterpenes. In order to evaluate the efficiency of the structure-based molecular networking, ethanol extract of Saussurea lappa (Decne.) C.B Clarke was investigated, which led to the isolation of two guaiane-type (1 and 14), ten eudesmane-type (2-5 and 8-13), two chain (6 and 7) and one germacrane-type (15) sesquiterpenes, including seven new ones, lappaterpenes A-G (1-7), which are reported on herein. The absolute configurations of the new compounds were established by coupling constants, calculated ECD and ROESY correlations, as well as comparisons of optical rotation values with those of known compounds. The absolute configuration of compound 2 was further confirmed by X-ray diffraction. Compounds 1-15 were evaluated for their potency against hepatitis B virus. Compounds 4, 6, 7 and 9 showed effect on HBsAg with inhibition ratios of more than 40% at 30 µM concentrations. Compounds 14 and 15 inhibited HBsAg secretion with the values of IC50 0.73 ± 0.18 and 1.43 ± 0.54 µM, respectively. Structure-based molecular networking inspired the discovery of target compounds.

[Effect of down-regulation of fatty acid synthase expression on proliferation, migration and invasion of bladder carcinoma UMUC3 cell lines].

OBJECTIVE: To investigate the effects of fatty acid synthase (FASN) on proliferation, migration and invasion of bladder cancer UMUC3 cell lines and possible mechanism. METHODS: The expression levels of FASN protein in 30 cases of bladder cancer and 15 cases of normal bladder tissues were detected by Immunohistochemistry. FASN siRNA and nonsense siRNA were transfected into UMUC3 cell lines by lipofectamine 2000 respectively, and the stable siFASN and siControl cell lines were successfully obtained after screening and identification for several times. The siFASN cell lines were set as the experimental group, while the siControl cell lines were set as the control group. The expressions of FASN protein and mRNA in the experimental group and the control group were detected by Western blot and real-time quantitative PCR (RT-PCR) respectively. Cell proliferation activities in two groups were detected by MTT assay and cell invasion and migration in two groups were detected by cell scratch test and Transwell invasive assays respectively. RESULTS: FASN protein was overexpressed in bladder cancer tissues, and it was closely correlated with pathological stage and grade (P＜0.05). Compared with the siControl group, the expressions of FASN mRNA and protein in the siFASN group cell lines were decreased significantly (P＜0.05). The cell proliferation ability, the migration ability and the number of transmembrane cells of siFASN group cell lines were reduced significantly (P＜0.05). CONCLUSION: The FASN overexpression may play an essential role in the development and progression of bladder cancer. Down-regulation of FASN expression can inhibit the proliferation, migration and invasion of bladder cancer cells, and inhibition of FASN expression is expected to be a new treatment for bladder cancer.