Baishi Zu

Negative-pressure cavitation extraction for the determination of flavonoids in pigeon pea leaves by liquid chromatography-tandem mass spectrometry

A new method, namely negative-pressure cavitation extraction (NPCE), followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) is presented for the extraction and quantification of flavonoids in pigeon pea leaves. This method combines the high efficiency of NPCE and the sensitivity and accuracy of MS/MS. The influential parameters of the NPCE procedure including liquid/solid ratio, extraction time, nitrogen flow and number of extraction cycles were optimized. Under optimized conditions, the efficiency of NPCE for extracting five flavonoids was compared to microwave-assisted extraction (MAE), ultrasonic extraction (USE) and heating reflux extraction (HRE). Additionally, structural disruption to pigeon pea leaves samples with different extraction methods was investigated by scanning electron microscopy. The relative recovery with NPCE was equivalent to or higher than that with USE and obviously higher than those with MAE and HRE which are usually conducted in higher temperatures. Furthermore, because NPCE was performed with nitrogen at room temperature, the degradation and oxidation of analytes were avoided. In addition, the NPCE method was validated in terms of repeatability and reproducibility, relative standard deviation for relative recovery was lower than 5.84 and 8.83%, respectively. The method was also successfully applied for the quantification of five flavonoids in pigeon pea leaves. All these results suggest that the developed NPCE-LC-MS/MS method represents an excellent alternative for the extraction and quantification of flavonoids in other plant materials.

Determination of paclitaxel and its analogues in the needles of Taxus species by using negative pressure cavitation extraction followed by HPLC-MS-MS.

A new separation method, negative pressure cavitation (NPC) extraction followed by HPLC-MS-MS for the determination of paclitaxel and its analogues in the needles of Taxus species is described in this study. Compared with three conventional extraction methods, NPC is a more effective, economical, and facile method for the separation of nature compounds from herbal plants. In contrast to high-temperature extraction, NPC at low temperature can minimize undesirable reactions such as thermal decomposition or degradation. In addition, the extraction mechanism of NPC was also illuminated. The effects of vacuum degree, extraction solvent, ratio of solid to liquid, time, and times extraction were studied and optimized. The optimum extraction conditions were as follows: vacuum degree -0.03 MPa, solvent 80% v/v alcohol, ratio of material to liquid 1:15 (g/mL), extraction time 60 min, extraction (x3). Using these conditions, the recoveries of 10-deacetyl-7-xylosylpaclitaxel, 10-deacetylpaclitaxel, cephalomannine, and paclitaxel were higher than 95.88, 95.82, 94.85, and 96.18%, respectively. The contents of paclitaxel, 10-deacetyl-7-xylosylpaclitaxel, 10-deacetylpaclitaxel, and cephalomannine for Taxus chinensis were 0.0053, 0.0467, 0.0132, and 0.0076%, and 0.0067, 0.0153, 0.0047, and 0.0064% for Taxus cuspidata, respectively. Furthermore, a comparison of SEM images observed the morphological changes of microstructures and cellular damage in yew needles.

In vitro and in vivo evaluation of camptothecin nanosuspension: A novel formulation with high antitumor efficacy and low toxicity

The purpose of this study was to evaluate the in vitro and in vivo antitumor efficacy and the dose dependent toxicity of camptothecin nanosuspension (Nano-CPT) comparing with that of topotecan (TPT). A novel supercritical antisolvent (SAS) process-high pressure homogenization technique has been developed to prepare Nano-CPT. The cytotoxicity of Nano-CPT and TPT was investigated against MCF-7, HCT-8, and PC-3 cell lines using MTT assay, antitumor activity in vivo were evaluated against HCT-8 xenograft model, and the dose dependent toxicity in vivo during the treatment were investigated by body weight changes and relative organ weight variations. The Nano-CPT presents about 6 times in vitro cytotoxicity active than TPT against cell lines MCF-7, nearly the same in vivo antitumor activity with TPT and lower toxicity. The results confirm that Nano-CPT is a novel potential formulation with high antitumor efficacy and low toxicity.