Derivatization of berberine based on its synergistic antifungal activity with fluconazole against fluconazole-resistant Candida albicans / 药学学报

Abstract: Our previous work revealed berberine can significantly enhance the susceptibility of fluconazole against fluconazole-resistant Candida albicans, which suggested that berberine has synergistic antifungal activity with fluconazole. Preliminary SAR of berberine needs to be studied for the possibility of investigating its target and SAR, improving its drug-likeness, and exploring new scaffold. In this work, 13-substitutited benzyl berberine derivatives and N-benzyl isoquinoline analogues were synthesized and characterized by 1H NMR and MS. Their synergetic activity with fluconazole against fluconazole-resistant Candida albicans was evaluated in vitro. The 13-substitutited benzyl berberine derivatives 1a-1e exhibited comparable activity to berberine, which suggested that the introduction of functional groups to C-13 can maintain its activity. The N-benzyl isoquinolines, which were designed as analogues of berberine with its D ring opened, exhibited lower activity than berberine. However, compound 2b, 2c, and 4b showed moderate activity, which indicated that berberine may be deconstructed to new scaffold with synergistic antifungal activity with fluconazole. The results of our research may be helpful to the SAR studies on its other biological activities.

Experimental studies of Panax notoginseng saponins and Ginkgo biloba extracts on preventing acute oxygen toxicity / 中国应用生理学杂志

<p><b>AIM</b>To investigate the preventive effects of Panax notoginseng saponins (PNS) and Ginkgo biloba extracts (GbE) on acute oxygen toxicity and the possible mechanisms.</p><p><b>METHODS</b>Mice were injected intraperitoneally with PNS and GbE for 5 days, then were exposed to 500 kPa hyperbaric oxygen (HBO) for 60 min, the convulsion latency, times and interval were observed. Moreover, reactive oxygen (RO) unit, MDA, NO, GSH levels and GSH-Px, CAT, MAO activities of mice brain were determined after they were exposed to HBO for 15 min.</p><p><b>RESULTS</b>PNS and GbE could markedly prolong the convulsion latency and interval, reduce convulsion times, decrease contents of MDA and NO in mice brain, keep RO unit, GSH and GSH-Px at higher levels, but had no effects on CAT and MAO activities.</p><p><b>CONCLUSION</b>PNS and GbE could effectively prevent acute oxygen toxicity, which were related to their antioxidant activities.</p>

Studies on NaNO2-induced DNA mutation by convolution spectrometry / 药学学报

<p><b>AIM</b>To study the sodium nitrite induced DNA mutation by convolution spectrometry (CS).</p><p><b>METHODS</b>The spectra of sodium nitrite-induced mutative calf thymus DNA was compared with ego criteria based on Spectra of the primary DNA within the wavelength range from 200 to 340 nm. Distilled water served as blank and normal saline served as negative control. Any difference was quantitatively expressed by differential value (delta) of convolution spectra. Near-infrared spectroscopy was employed as the reference method.</p><p><b>RESULTS</b>The differential value was positively correlated with the increasing time and concentration of sodium nitrite. delta values increased to 1.37%, 2.41% and 5.44% respectively within 2-hour's reaction between calf thymus DNA and 0.5, 0.05 and 0.005 microgram.mL-1 sodium nitrite, while on the contrary, changes could be hardly observed on the corresponding UV absorption spectra. The results were also confirmed by their corresponding near-infrared spectra.</p><p><b>CONCLUSION</b>The delta values can be used to represent the compound's strength of mutagenesis. Every convolution procedure takes less than one minute, so CS provides a fast, simple and inexpensive alternative method to determine chemical or medicinal DNA mutation.</p>