Zhi-Min Zhao

Thin-layer chromatographic identification of Chinese propolis using chemometric fingerprinting.

INTRODUCTION Poplar tree gum has a similar chemical composition and appearance to Chinese propolis (bee glue) and has been widely used as a counterfeit propolis because Chinese propolis is typically the poplar-type propolis, the chemical composition of which is determined mainly by the resin of poplar trees. The discrimination of Chinese propolis from poplar tree gum is a challenging task. OBJECTIVE To develop a rapid thin-layer chromatographic (TLC) identification method using chemometric fingerprinting to discriminate Chinese propolis from poplar tree gum. METHODS A new TLC method using a combination of ammonia and hydrogen peroxide vapours as the visualisation reagent was developed to characterise the chemical profile of Chinese propolis. Three separate people performed TLC on eight Chinese propolis samples and three poplar tree gum samples of varying origins. Five chemometric methods, including similarity analysis, hierarchical clustering, k-means clustering, neural network and support vector machine, were compared for use in classifying the samples based on their densitograms obtained from the TLC chromatograms via image analysis. RESULTS Hierarchical clustering, neural network and support vector machine analyses achieved a correct classification rate of 100% in classifying the samples. A strategy for TLC identification of Chinese propolis using chemometric fingerprinting was proposed and it provided accurate sample classification. CONCLUSION The study has shown that the TLC identification method using chemometric fingerprinting is a rapid, low-cost method for the discrimination of Chinese propolis from poplar tree gum and may be used for the quality control of Chinese propolis.

Diterpenoids from aerial parts of Flickingeria fimbriata and their nuclear factor-kappaB inhibitory activities.

Chemical investigation of the aerial parts of Flickingeria fimbriata (Bl.) Hawkes resulted in isolation of sixteen ent-pimarane diterpenoids, including five rare 16-nor-ent-pimarane diterpenoids, two 15,16-dinor-ent-pimarane diterpenoids and one ent-pimarane diterpenoid. Structures were mainly elucidated by extensive spectroscopic analysis, and their absolute configurations were unequivocally determined by the exciton chirality method, the modified Moshers method, the CD experiments (including Snatzkes method) and chemical transformations, respectively. All the isolated compounds were screened for inhibitory effects on the nuclear factor-kappaB (NF-κB) in lipopolysaccharide (LPS) induced murine macrophage RAW264.7 cells, using a NF-κB-dependent luciferase reporter gene assay. Several of these compounds displayed comparable or even better activities than the positive control pyrrolidinedithiocarbamate (PDTC) (IC50=26.3 μM) with IC50 values in the range of 14.7-29.2 μM and structure-activity relationships are briefly proposed.

Natural nitric oxide (NO) inhibitors from Chloranthus japonicus

Eight new lindenane sesquiterpenoid dimers, chlojapolides A-H (1-8), along with 11 known analogues were isolated from the whole plant of Chloranthus japonicus. Their structures including absolute configurations were elucidated by spectral and chemical methods. All the compounds were examined for their inhibitory effects on the nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW 264.7 macrophages, and compounds 1, 11, 13, and 17 exhibited pronounced inhibition with IC50 values in the range of 6.91-15.75μM, being more active than the positive control, quercetin (IC50=15.90μM).

Chlojaponilactone B from Chloranthus japonicus: Suppression of Inflammatory Responses via Inhibition of the NF-κB Signaling Pathway

Bioassay-guided fractionation of an ethanolic extract of Chloranthus japonicus led to the isolation of the known lindenane-type sesquiterpenoid chlojaponilactone B (1). This compound exhibited pronounced inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Further anti-inflammatory assays showed that 1 suppressed the levels of some key inflammation mediators, such as iNOS, TNF-α, and IL-6, in a dose-dependent manner, and reduced the ear thickness and neutrophil infiltration in 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated mice. A mechanistic study revealed that compound 1 exerted its anti-inflammatory effects via the suppression of the NF-κB signaling pathway, which inhibited NF-κB-dependent transcriptional activity, IκBα phosphorylation, and p65 nuclear translocation. In contrast, chlojaponilactone B (1) was found to exert little influence on the MAPK signaling pathway.

Bioactive norditerpenoids from Flickingeria fimbriata

Seven new degraded diterpenoids (1–6 and 11), four new ent-pimarane type diterpenoids (7–10) and a known analogue (12) were isolated from the stem of Flickingeria fimbriata. Compounds 1–4, namely norflickinflimiods A–D, possessed a rare 16-nor-ent-pimarane skeleton, and 5–6, namely norflickinflimiods E and F, represented an unusual skeleton of 15,16-dinor-ent-pimarane. The structures including the absolute configurations of 1–12 were elucidated using spectroscopic analysis, single-crystal X-ray diffraction, computational methods, and chemical correlations. All the isolates were screened for anti-inflammatory and antitumor activities, and compounds 5, 6, 9, and 12 showed potent inhibitory activities against lipopolysaccharide (LPS)-induced TNF-α production in RAW264.7 cells with IC50 values less than 10 μM, while compounds 8–11 exhibited cytotoxicity against MCF-7 cells (9.6, 9.0, 12.0, and 15.6 μM).

A novel bioconversion for value-added products from food waste using Musca domestica

Food waste, as a major part of the municipal solid waste has been generated increasingly worldwide. Efficient and feasible utilization of this waste material for productivity process is significant for both economical and environmental reasons. In the present study, Musca domestica larva was used as the carrier to conduct a bioconversion with food waste to get the value-added maggot protein, oil and organic fertilizers. Methods of adult flies rearing, culture medium adjuvant selection, maggot culture conditions, stocking density and the valorization of the waste have been explored. From the experimental results, every 1000g culture mediums (700g food waste and 300g adjuvant) could be disposed by 1.5g M. domestica eggs under proper culture conditions after emergence in just 4days, 42.95±0.25% of which had been consumed and the culture medium residues could be used as good organic fertilizers, accompanying with the food waste consumption, ∼53.08g dried maggots that contained 57.06±2.19% protein and 15.07±2.03% oil had been produced. The maggot protein for its outstanding pharmacological activities is regarded as a good raw material in the field of medicine and animal feeding. Meanwhile, the maggot oil represents a potential alternative feedstock for biodiesel production. In our study, the maggot biodiesel was obtained after the procedure of transesterification reaction with methanol and the productivity was 87.71%.

Solidification of floating organic drop liquid-phase microextraction cell fishing with gas chromatography–mass spectrometry for screening bioactive components from Amomum villosum Lour

In this study, a novel solidification of floating organic drop liquid-phase microextraction cell fishing with gas chromatography-mass spectrometry (SFOD-LPME-CF-GC-MS) method was established and used to screen, isolate and analyze bioactive components from Amomum villosum Lour. extract. Through comparision of its effect on the models of normal cell and inflammatory cells, anti-inflammatory active components of essential oil from A. villosum Lour. were readily screened, and the components obtained are in agreement with related pharmacological articles. SFOD-LPME-CF-GC-MS was used to analyze the interaction of A. villosum Lour. extracts with normal and lipopolysaccharide-stimulated RAW264.7 macrophage cells. The effect of A. villosum Lour. essential oil extracts in the LPS-stimulated RAW264.7 model were also assessed in terms of cytotoxicity and nitric oxide production as an indication of bioactivity. Three potentially bioactive components were identified, demonstrating that SFOD-LPME-CF-GC-MS can be used successfully in the drug-screening process. This approach avoids the requirement for protein precipitation, but more importantly, generates a high concentration ratio, allowing analysis of trace components in traditional Chinese medicines. SFOD-LPME-CF-GC-MS is a simple, fast, effective and reliable method for the screening and analysis of bioactive components, and it can be extended to screen other bioactive components from TCMs.

Norditerpenoids from Flickingeria fimbriata and Their Inhibitory Activities on Nitric Oxide and Tumor Necrosis Factor-α Production in Mouse Macrophages

Bioassay-guided fractionation of the ethanolic extract of the leaves of Flickingeria flimbriata led to the isolation of two new degraded diterpenoids 1 and 2, a new ent-pimarane type diterpenoid 3, and four known steroids 4–7. The structures of 1–3 were elucidated by spectroscopic analysis, and their absolute configurations were determined by chemical methods, TDDFT quantum chemical calculations of ECD spectra, and CD exiton chirality method. Compounds 1 and 2, named flickinflimilins A and B, possess a rare 15,16-dinor-ent-pimarane skeleton. Compounds 1–7 were screened for the inhibitory activity against lipopolysaccharide (LPS)-induced NO and TNF-α production in RAW264.7 cells. Compounds 1–3 exhibited potent inhibitory activities, with IC50 values of less than 10 µM.

A new triterpenoid saponin and an oligosaccharide isolated from the fruits of Sapindus mukorossi

A new triterpenoid saponin (1) and a new oligosaccharide (2), together with three known saponins (3–5), have been isolated from n-BuOH extract of the fruits of Sapindus mukorossi Gaertn. The structures were elucidated using detailed analysis of one- and two-dimensional nuclear magnetic resonance spectra along with their mass spectrometric data and the results of acid hydrolysis. Of the isolated compounds 1 and 3–5 displayed cytotoxic effects against human cancer cell lines in A-549 (lung carcinoma), MDA-231 (breast carcinoma) and PC-3 (prostatic carcinoma).

Determination of Flavonoids by Solidification of Floating Organic Drop Liquid-Phase Microextraction and High-Performance Liquid Chromatography

ABSTRACT Solidification of floating organic drop liquid-phase microextraction coupled with high-performance liquid chromatography (HPLC) is reported for the preconcentration and determination of three flavonoids in Amomum villosum Lour. Amomum villosum Lour. samples from eight locations were analyzed. The parameters affecting the performance of solidification of floating organic drop liquid-phase microextraction coupled with HPLC were optimized. Under these conditions, the linear dynamic ranges for quercetin, quercitrin, and isoquercitrin were 1.68 × 10−2 to 10.0, 3.37 × 10−2 to 10.0, and 6.75 × 10−2 to 10.0 µg/mL, respectively. The limits of detection were 8.4, 12.5, and 25.0 ng/mL. The intra- and inter-day relative standard deviation values were less than 10.5%. The recoveries of the analytes in A. villosum Lour. were between 84.0 and 109.8%. Enrichment factors for solidification of floating organic drop liquid-phase microextraction coupled with HPLC were from 2.1 to 42.7. The results show that A. villosum Lour. from various locations contained significant differences in flavonoid concentrations. The mechanism of solidification of supramolecule ordering assembly liquid-phase microextraction was characterized using ultraviolet spectra of the analytes before and after pretreatment. Solidification of floating organic drop liquid-phase microextraction coupled with HPLC was simple, rapid, sensitive, and suitable for quality control of A. villosum Lour.