DNA and RNA sensor

Bioassay of ferulic acid derivatives as influenza neuraminidase inhibitors

Four series of ferulic acid derivatives were designed, synthesized, and evaluated for their neuraminidase (NA) inhibitory activities against influenza virus H1N1 in vitro. The pharmacological results showed that the majority of the target compounds exhibited moderate influenza NA inhibitory activity, which was also better than that of ferulic acid. The two most potent compounds were 1m and 4a with IC₅₀ values of 12.77 ± 0.47 and 12.96 ± 1.34 μg/ml, respectively. On the basis of the biological results, a preliminary structure-activity relationship (SAR) was derived and discussed. Besides, molecular docking was performed to study the possible interactions of compounds 1p, 2d, 3b, and 4a with the active site of NA. It was found that the 4-OH-3-OMe group and the amide group (CON) of ferulic acid amide derivatives were two key pharmacophores for NA inhibitory activity. It is meaningful to further modify the natural product ferulic acid to improve its influenza NA inhibitory activity.

Phenolic compounds from Eurycorymbus cavaleriei

Three new phenolic compounds, eurycorymboside A (1), eurycorymboside B (6), and eurycorymbic acid (8), were isolated from the stem part of Eurycorymbus cavaleriei (Sapindaceae) along with five known phenolic compounds, glucosyringic acid (2), vanillic acid 4-O-β-d-glucoside (3), koaburaside (4), tachioside (5), and 4-hydroxy-3,5-bis(3-methyl-2-butenyl)benzaldehyde (7). The structures were established on the basis of spectral analysis. The antioxidant activities of compounds 1-6 were evaluated by the 1,1-diphenyl-2-picrylhydrazyl-free radical scavenging assay. Compound 4 exhibited antioxidant activity with an IC(50) value of 9.0 μM. Compound 4 also showed weak inhibitory activity against influenza A neuraminidase.

Label-free DNA sensor based on fluorescent cationic polythiophene for the sensitive detection of hepatitis B virus oligonucleotides

Water-soluble fluorescent conjugated polymers can be used as an optical platform in highly sensitive DNA sensors. Here we report a simple label-free DNA sensor using poly(3-alkoxy-4-methylthiophene) to recognize and detect different oligonucleotide targets related to the YMDD gene mutation of hepatitis B virus. The concentration of surfactant Triton X-100, NaCl, the oligonucleotide capture probe and the oligonucleotide hybridization conditions have a great impact on fluorescence intensity. Under the optimum conditions, two types of oligonucleotide targets involving YMDD gene mutation of hepatitis B virus were successfully recognized. Moreover, there was a linear relationship between fluorescence intensity and the concentration of oligonucleotide target. The detection limit of the wild-type hepatitis B virus target is 88 pmol L(-1).

The value of natural products to future pharmaceutical discovery

Natural products have provided considerable value to the pharmaceutical industry over the past half century. In particular, the therapeutic areas of infectious diseases and oncology have benefited from numerous drug classes derived from natural product sources. Unfortunately, pharmaceutical companies have significantly decreased activities in natural product discovery during the past several years. Biotechnology companies working in the fields of combinatorial biosynthesis, genetic engineering and metagenomic approaches to identify novel natural product lead molecules have had limited success. Despite what appears to be a slow death of natural product discovery research, many new and interesting molecules with biological activity have been published in the past few years. If natural product materials continue to be tested for desirable therapeutic activities, we believe that significant progress in identifying new antibiotics, oncology therapeutics and other useful medicines will be made.