Structure Analysis of Effective Chemical Compounds against Dengue Viruses Isolated from Isatis tinctoria.
ABSTRACT: The history of Chinese herb research can be traced back to thousands of years ago, and the abundant knowledge accumulated for these herbs makes them good candidates for developing new natural drugs. Isatis tinctoria is probably the most well-studied Chinese herb, which has been identified to be effective against dengue fever. However, the underlying biological mechanisms are still unclear. In this study, we adopt combined methods of bioactive trace technology and phytochemical extraction and separation, to guide the isolation and purification of the effective chemical constituents on the water-soluble components of aerial parts of Isatis tinctoria. In addition, we apply polarimetry and 1D or 2D nuclear magnetic resonance (NMR) spectroscopy to identify their structures, which lay a foundation for further study on the biological mechanisms underlying medicinal effects of Isatis tinctoria using in vitro and in vivo experiments. Specifically, we identify and infer the structures of 27 types of chemical compounds named GB-1, GB-2,?…,?GB-27, respectively, among which GB-7 is a novel compound. Further study of these compounds is critical to reveal the secrets behind the medicinal effects of Isatis tinctoria.
Project description:As our ongoing research project on Ban Lan Gen (Isatis tinctoria roots), a total of 23 alkaloids were obtained. Compounds 1 and 2 contain an unusual C-C bond between the 2(1H)-quinolinone moiety and the phenol moiety and between the 2(1H)-quinolinone moiety and the 1H-indole moiety, respectively. Compound 3 possesses an unusual carbon skeleton and its putative biosynthetic pathway was discussed, and Compound 23 was deduced as a new indole alkaloid glycoside. Compounds 4-7 were identified as four new natural products by extensive spectroscopic experiments. Additionally, the anti-inflammatory activity was assessed based on nitric oxide (NO) production using Lipopolysaccharide-stimulated RAW264.7 macrophages. Compounds 9, 15, and 17 showed inhibitory effects with IC50 values of 1.2, 5.0, and 74.4 ?M.
Project description:Secondary metabolites have been extensively used in the treatment of various health problems. The role of solvent polarity on the phytochemical isolation and antioxidant capacity of Isatis tinctoria (woad) is elusive. In the present study, 14 solvents with different polarity were used in the extraction and total phenolic and flavonoid content (TPC and TFC) investigation. Ferricyanide, phosphomolybdenum, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods were used to calculate and compare the antioxidant/free radical scavenging capacity. Our results showed that solvent polarity greatly affects TPC and TFC yield, which is mainly increasing with increasing solvent polarity index and suddenly decreasing at very high polarity. The comparative results showed that TPC is directly correlated with reducing power, antioxidant, and free radical scavenging capacity. Taken together, we conclude that different woad plant parts contain different level of secondary metabolites with a specific polarity that requires a particular solvent with an appropriate polarity index for the extraction. The identification of these biologically active crude extracts and fractions are very important for the basic biological sciences, pharmaceutical applications, and future research for HPLC based active compounds isolation.
Project description:BACKGROUND:Pseudorabies virus (PRV) is an animal virus that is globally responsible for the high economic losses in the swine industry. Isatis root is a traditional Chinese medicinal herb that possesses immune-enhancing and antiviral properties. However, the molecular mechanisms underlying the effects of the active component of the isatis root polysaccharide (IRPS) extract on immature dendritic cells remain elusive. METHODS:In this study, we investigated the molecular changes in primary porcine peripheral blood monocyte-derived dendritic cells (MoDCs) during PRV infection, using enzyme-linked immunosorbent assay (ELISA) and quantitative reverse transcription-polymerase chain reaction. Additionally, we studied the effect of IRPS on PRV-infected DCs. RESULTS:The results showed that IRPS stimulated the maturation of MoDCs, induced IL-12 secretion, and downregulated IL-6 expression. CONCLUSIONS:Collectively, these results suggest that IRPS is a promising candidate for promoting maturation of DCs and enhancing their secretory potential after PRV infection.
Project description:In this work, Isatis tinctoria hairy root cultures (ITHRCs) were established as an alternative source for flavonoids (FL) production. I. tinctoria hairy root line V was found to be the most efficient line and was further confirmed by the PCR amplification of rolB, rolC and aux1 genes. Culture parameters of ITHRCs were optimized by Box-Behnken design (BBD), and eight bioactive FL constituents (rutin, neohesperidin, buddleoside, liquiritigenin, quercetin, isorhamnetin, kaempferol and isoliquiritigenin) were quali-quantitatively determined by LC-MS/MS. Under optimal conditions, the total FL accumulation of ITHRCs (24 day-old) achieved was 438.10 ?g/g dry weight (DW), which exhibited significant superiority as against that of 2 year-old field grown roots (341.73 ?g/g DW). Additionally, in vitro antioxidant assays demonstrated that ITHRCs extracts exhibited better antioxidant activities with lower IC?? values (0.41 and 0.39, mg/mL) as compared to those of field grown roots (0.56 and 0.48, mg/mL). To the best of our knowledge, this is the first report describing FL production and antioxidant activities from ITHRCs.