Target-guided isolation and purification of cyclooxygenase-2 inhibitors from Meconopsis integrifolia (Maxim.) Franch. by high-speed counter-current chromatography combined with ultrafiltration liquid chromatography.

Meconopsis integrifolia (Maxim.) Franch. is used extensively in traditional Tibetan medicine for its potent anti-inflammatory properties. In this study, six cyclooxygenase-2 (COX-2) inhibitors were purified from M. integrifolia using high-speed counter-current chromatography guided by ultrafiltration liquid chromatography (ultrafiltration-LC). First, ultrafiltration-LC was performed to profile the COX-2 inhibitors in M. integrifolia. The reflux extraction conditions were further optimized using response surface methodology, and the results showed that the targeted COX-2 inhibitors could be well enriched under the optimized extraction conditions. Then the six target COX-2 inhibitors were separated by high-speed countercurrent chromatography with a solvent system composed of ethyl acetate/n-butanol/water (4:1:4, v/v/v. Finally, the six COX-2 inhibitors, including 21.2 mg of 8-hydroxyluteolin 7-sophoroside, 29.6 mg of 8-hydroxyluteolin 7-[6'''-acetylallosyl-(1→2)-glucoside], 42.5 mg of Sinocrassoside D3, 54.1 mg of Hypolaetin 7-[6'''-acetylallosyll-(l→2)-3''-acetylglucoside, 30.6 mg of Hypolaetin 7-[6'''-acetylallosyll-(l→2)-6''-acetylglucoside and 17.8 mg of Hypolaetin were obtained from 500 mg of sample. Their structures were elucidated by 1 H-NMR spectroscopy. This study reveals that ultrafiltration-LC combined with high-speed counter-current chromatography is a robust and efficient strategy for target-guided isolation and purification of bioactive molecules. It also enhances the scientific understanding of the anti-inflammatory properties of M. integrifolia but also paves the way for its further medicinal applications.

An efficient strategy for large-scale preparation of low polarity gingerols directly from ginger crude extract by high-speed countercurrent chromatography with different rotation mode.

This study presents an efficient strategy for large-scale preparation of low polarity gingerols directly from ginger crude extract by high-speed countercurrent chromatography with different rotation mode. The ultrasonic-assisted extraction conditions were optimized by response surface methodology and the results showed the major low polarity gingerols could be well enriched under the optimized extraction conditions. Then the crude extract without any pretreatment was directly separated by high-speed countercurrent chromatography with different rotation mode using n-hexane/ethyl acetate/methanol/water (6:4:6:4, v/v/v/v) as the solvent system. In about 400 min, five major gingerols including 150 mg of [6]-gingerol, 50 mg of [8]-gingerol, 20 mg of [6]-shogaol, 43 mg of [6]-dehydrogingerdione, and 40 mg of [10]-gingerol were obtained from 1.2 g of crude extract in a single run with repeated injection. Their structures were identified by 1 H-NMR spectroscopy.

Target-Guided Isolation and Purification of Antioxidants from Urtica laetevirens Maxim. by HSCCC Combined with Online DPPH-HPLC Analysis.

Urtica laetevirens Maxim. is used extensively in traditional Chinese medicine (TCM) for its potent antioxidative properties. In this study, three antioxidants were purified from U. laetevirens. using HSCCC guided by online DPPH-HPLC analysis. Firstly, the online DPPH-HPLC analysis was performed to profile out the antioxidant active molecules in U. laetevirens. The ultrasonic-assisted extraction conditions were optimized by response surface methodology and the results showed the targeted antioxidant active molecules could be well enriched under the optimized extraction conditions. Then, the antioxidant active molecules were separated by high-speed countercurrent chromatography ethyl acetate/n-butanol/water (2:3:5, v/v/v) as the solvent system. Finally, the three targets including 16.8 mg of Isovitexin, 9.8 mg of Isoorientin, and 26.7 mg of Apigenin-6,8-di-C-ß-d-glucopyranoside were obtained from 100 mg of sample. Their structures were identified by 1H NMR spectroscopy.

Time-Domain-Based Methyl Proton NMR with Absolute Quantitation Ability for Targeted Metabolomics.

In high-throughput scenarios of targeted metabolomics, it is a significant challenge to process complex NMR spectra with severely overlapping signals produced by metabolites with similar chemical structures. Traditional frequency-domain NMR is ineffective to some degree due to the low sensitivity and poor resolution, and the precision of quantitation is usually affected by poorly or inconsistently phased and baselined spectra. Here, we established a strategy based on time-domain NMR focusing on methyl protons for targeted metabolomics. The targeted metabolomics focusing on bufadienolides for varietal discrimination of three toad venoms was conducted to demonstrate the practicability of time-domain-based methyl proton NMR. It revealed that the signals could be precisely identified and quantitated with an signal-to-noise ratio (SNR) of about 10 and a resolution of about 1.0 Hz. The sensitivity and resolution improvement make it particularly applicable in targeted metabolomics. The precise and absolute quantitation ability confirmed by triple-quadrupole mass spectrometry (QqQ-MS) could further extend its application range. Importantly, the methyl group is common in metabolites with a relatively wide chemical shift range. Time-domain analysis could be conducted in common NMR software. This technique is very easy and convenient for general researchers when employed as a complementary alternative to traditional frequency-domain NMR, especially in the field of targeted metabolomics.

A new amine isolated from Urtica thunbergiana Siebold & Zucc.

One new amine 2-dimethyl-Penidilamine (1), together with seventeen known compounds (2-18) were isolated from the 95% ethanol extract of Urtica thunbergiana Siebold & Zucc. Their structures were characterised by extensive spectroscopic analysis including NMR, mass spectra and single X-ray crystallography. Among them, compound 1 is a new compound, and compounds 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17 and 18 were isolated from Urtica thunbergiana Siebold & Zucc for the first time. Among them, compound 1, 10, 15, 17 and 18 exhibited significant α-glucosidase inhibitory activity with an IC50 value of 65.12 µM, 7.42 µM, 26.24 µM, 71.31 µM and 72.55 µM, respectively. Our study provided the scientific report for the medicinal value of Urtica thunbergiana Siebold & Zucc.

Activity labelled molecular networking fuels the antioxidation active molecules profile of Ginger.

Ginger has been used as consumed food spice and folk medicine in daily life for thousands of years in various regions of the world. Considerable antioxidation is one of the major activities for Ginger to exhibit health-promoting effects. In this study, a bioinformatic workflow was developed to generate activity labelled molecular networking (ALMN) to fuel the antioxidation active molecules profile of Ginger. In ALMN, antioxidation activity data, which was defined as correlation (r and p value) between the relative abundance of a molecule in fractions and the activity level of each fraction, was labelled to feature-based molecular network to profile out antioxidation active molecules visually. Fragmentation tree was further computed as a complementary way to conduct high confidence structure annotations of antioxidation active molecules. Consequently, 48 molecules were prioritized as antioxidation active molecules from 11,720 metabolite molecules of Ginger in a systematical way.

Ab initio calculation based solvent system selection in silico for counter-current chromatography: Separation of resibufogenin glycosylation products.

In this study, a strategy based on COSMO-RS (Conductor-like Screening Model for Real Solvents) with a constrained optimization calculation was developed for ab initio calculation based solvent system selection in silico for counter-current chromatography. The separation of resibufogenin glycosylation products was selected as an example to show its practicability. The selected solvent system in silico gave the K values consistent with the experimentally measured data (RMSD=0.2861) and the glycosylation products, namely Resibufogenin-3-O-ß-D-glucoside (R-G) and Resibufogenin-3-O-ß-D-glucosyl (1→2)-ß-D-glucoside (R-2G), were successfully separated by HSCCC.