A comprehensive study on solvent effect and establishment of n-hexane solvent system based normal-phase liquid chromatography × reversed-phase liquid chromatography for isolation of natural products.

Reversed-phase liquid chromatography (RPLC) represents an effective separation method, and is widely employed as the second dimension in most 2D-LC systems. Nevertheless, the solvent effect of the eluent from the first dimension on RPLC presents a challenge to the online coupling of RPLC with other separation modes, particularly normal phase liquid chromatography (NPLC). To address this issue, a comprehensive understanding of the solvent effect is essential.

Hinokione: an abietene diterpene with pancreatic β cells regeneration and hypoglycemic activity, and other derivatives with novel structures from the woods of Agathis dammara.

In this study, 14 abietene and pimarene diterpenoids were isolated from the woods of Agathis dammara. Among them, 4 new compounds, dammarone A-C and dammaric acid A (1-4), were firstly reported, respectively. The structure of the new compounds was determined by HR ESI-MS and 1D/2D NMR spectroscopy, and their absolute configuration was determined by electronic circular dichroism (ECD) exciton chirality method.

Compounds from Agathis dammara exert hypoglycaemic activity by enhancing glucose uptake: lignans, terpenes and others.

In this study, two new kaurane diterpenes (16, 17), together with 12 lignans (1-12), a triterpene (15), and two other compounds (13, 14) were isolated from the woods of Agathis dammara. The structure of the new compound was determined by HR ESIMS and 1D/2D NMR spectroscopy, and its absolute configuration was determined by electronic circular dichroism (ECD) exciton chirality method. Compounds 5, 11, 14 exhibit significant hypoglycaemic activity in zebrafish, and their mechanism of action is to enhance glucose uptake in zebrafish.

Global trends in colorectal cancer and metabolic syndrome research: a bibliometric and visualization analysis.

Numerous studies have demonstrated a robust correlation between metabolic syndrome (MetS) and colorectal cancer (CRC). Nonetheless, no systematic analysis or visualization of relevant publications has been conducted via bibliometrics. This research, centred on 616 publications obtainable through the Web of Science Core Collection (WoSCC), employed CiteSpace software and VOSviewer software for correlation analyses of authors, journals, institutions, countries, keywords, and citations.

New cyclopentenoneacrylic acid derivatives from a marine-derived fungus H548.

Three new cyclopentenoneacrylic acid derivatives, trichodermacid A (), trichodermester A (), and trichodermester B (), together with thirteen known compounds, were isolated from an ethyl acetate extract of H548, a fungus derived from mangrove sediment. The structures of the new compounds were elucidated by spectroscopic methods including HR ESI-MS, H NMR, C NMR, and 2D-NMR techniques. The antifungal activity of the isolated compounds was evaluated against tea pathogenic fungus .

Two New Cytotoxic Compounds from a Deep-Sea XT20-134.

XT20-134 (MCCC 3A00956) is a fungus with cytotoxic activity, derived from deep-sea sediment. Five new compounds, adeninylpyrenocine (), 2-hydroxyl-3-pyrenocine-thio propanoic acid (), ozazino--(2,3-dihydroxyl-trp-tyr) (), 5,5-dichloro-1-(3,5-dimethoxyphenyl)-1,4-dihydroxypentan-2-one (), and 2,3,4-trihydroxybutyl cinnamate (), together with 19 known compounds (-), were isolated from an ethyl acetate (EtOAc) extract of its fermentation. The structures of the new compounds were comprehensively characterized by high-resolution electrospray ionization-mass spectrometry (HR-ESI-MS), 1D and 2D nuclear magnetic resonance (NMR).

New β-Lactone with Tea Pathogenic Fungus Inhibitory Effect from Marine-Derived Fungus MCCC3A00957.

Fusarium solani H915 (MCCC3A00957), a fungus originating from mangrove sediment, showed potent inhibitory activity against tea pathogenic fungus Pestalotiopsis theae. Successive chromatographic separation on an ethyl acetate (EtOAc) extract of F. solani H915 resulted in the isolation of five new alkenoic diacid derivatives: fusarilactones A-C (1-3), and fusaridioic acids B (4) and C (5), in addition to seven known compounds (6-12).

Open-Ring Butenolides from a Marine-Derived Anti-Neuroinflammatory Fungus Y10.

To investigate structurally novel and anti-neuroinflammatory natural compounds from marine-derived microorganisms, the secondary metabolites of Y10, a fungus separated from the sediment of the coast in the South China Sea, were studied. Three new compounds (⁻), with novel open-ring butenolide skeletons, were isolated from the ethyl acetate extract of the culture medium. In addition, a typical new butenolide, asperteretal F (), was found to dose-dependently inhibit tumor necrosis factor (TNF-α) generation with an IC of 7.

Development of an on-line mixed-mode gel liquid chromatography×reversed phase liquid chromatography method for separation of water extract from Flos Carthami.

A novel on-line comprehensive two-dimensional liquid chromatography (2D-LC) method by coupling mixed-mode gel liquid chromatography (MMG-LC) with reversed phase liquid chromatography (RPLC) was developed. A mixture of 17 reference compounds was used to study the separation mechanism. A crude water extract of Flos Carthami was applied to evaluate the performance of the novel 2D-LC system.

A chalcone derivative reactivates latent HIV-1 transcription through activating P-TEFb and promoting Tat-SEC interaction on viral promoter.

The principal barrier to the eradication of HIV/AIDS is the existence of latent viral reservoirs. One strategy to overcome this barrier is to use latency-reversing agents (LRAs) to reactivate the latent proviruses, which can then be eliminated by effective anti-retroviral therapy. Although a number of LRAs have been found to reactivate latent HIV, they have not been used clinically due to high toxicity and poor efficacy.

Two new cytochalasan derivatives from Chaetomium globosum SNSHI-5, a fungus derived from extreme environment.

Two new cytochalasan derivatives, isochaetoglobosin D (1) and cytoglobosin A (2), were isolated from an ethyl acetate extract of Chaetomium globosum SNSHI-5, a fungus derived from extreme environment. The structures of the new compounds were comprehensively characterized by HR-ESI-MS, H NMR, C NMR and 2D-NMR. Cytotoxic activity against H292 human lung cancer cell of the new compounds was tested.

Comprehensive two-dimensional normal-phase liquid chromatography × reversed-phase liquid chromatography for analysis of toad skin.

An analytical two-dimensional normal-phase liquid chromatography × reversed-phase liquid chromatography (2D NPLC × RPLC) system was constructed with a newly developed thermal evaporation assisted adsorption (TEAA) interface. This novel TEAA interface with heating temperature above solvent boiling point allowed fast removal of organic NPLC solvent and successfully solved the solvent incompatibility problem between NPLC and RPLC. The system achieved rapid on-line solvent exchange between the two dimensions within a short modulation time of 190 s and was applied in the analysis of an extract from the skin of Bufo bufo gargarizans.

New on-line separation workflow of microbial metabolites via hyphenation of analytical and preparative comprehensive two-dimensional liquid chromatography.

Microbial metabolites represent an important source of bioactive natural products, but always exhibit diverse of chemical structures or complicated chemical composition with low active ingredients content. Traditional separation methods rely mainly on off-line combination of open-column chromatography and preparative high performance liquid chromatography (HPLC). However, the multi-step and prolonged separation procedure might lead to exposure to oxygen and structural transformation of metabolites.

Biosynthetic Functional Gene Analysis of Bis-Indole Metabolites from 25D7, a Clone Derived from a Deep-Sea Sediment Metagenomic Library.

This work investigated the metabolites and their biosynthetic functional hydroxylase genes of the deep-sea sediment metagenomic clone 25D7. 5-Bromoindole was added to the 25D7 clone derived Escherichia coli fermentation broth. The new-generated metabolites and their biosynthetic byproducts were located through LC-MS, in which the isotope peaks of brominated products emerged.

Novel N-Substituted 2-(2-(Adamantan-1-yl)-1H-Indol-3-yl)-2-Oxoacetamide Derivatives: Synthesis and Biological Evaluation.

In this study, a series of novel N-substituted 2-(2-(adamantan-1-yl)-1H-indol-3-yl)-2-oxoacetamide derivatives were synthesized, and evaluated for their cytotoxicity in human cell lines including Hela (cervical cancer), MCF7 (breast cancer ) and HepG2 (liver cancer). Several compounds were found to have potent anti-proliferative activity against those human cancer cell lines and compound 5r showed the most potent biological activity against HepG2 cells with an IC50 value of 10.56 ± 1.

A new macrolactin antibiotic from deep sea-derived bacteria Bacillus subtilis B5.

A new macrolactin derivate, 7-O-2'E-butenoyl macrolactin A (1), together with three known macrolactin compounds, macrolactin A (2), 7-O-malonyl macrolactin A (3) and 7-O-succinyl macrolactin A (4), was isolated from the bacterial strain Bacillus subtilis B5, which was isolated from the 3000 m deep sea sediment of the Southwest Pacific Ocean. The structures of the new compounds were assigned by spectroscopic methods including 1-D/2-D NMR and MS analysis techniques. Compounds 1 and 2 demonstrated antifungal activities against tea pathogenic fungi Pestalotiopsis theae and Colletotrichum gloeosporioides.

Tracing the nitrogen metabolites of glycine using (15)N-glycine and mass spectrometry.

Rationale: Glycine is the smallest amino acid used in protein synthesis, but it is also a very important precursor for the biosynthesis of other nitrogen-containing metabolites, such as purine nucleosides and nucleotides for synthesis of RNA, DNA etc. Abnormalities in glycine metabolism therefore cause diseases such as cancer. A quick and unambiguous method to trace the metabolites arising from glycine is required for targeting defect points within metabolic networks.

On-line two-dimensional countercurrent chromatography×high performance liquid chromatography system with a novel fragmentary dilution and turbulent mixing interface for preparation of coumarins from Cnidium monnieri.

This study describes a novel on-line two-dimensional countercurrent chromatography×high performance liquid chromatography (2D CCC×HPLC) system for one-step preparative isolation of coumarins from the fruits of Cnidium monnieri. An optimal biphasic solvent system composed of n-heptane/acetone/water (31:50:19, v/v) with suitable Kd values and a higher retention of the stationary phase was chosen to separate target compounds. In order to address the solvent incompatibility problem between CCC and RP-HPLC, a novel fragmentary dilution and turbulent mixing (FD-TM) interface was successfully developed.

Online polar two phase countercurrent chromatography×high performance liquid chromatography for preparative isolation of polar polyphenols from tea extract in a single step.

Herein, we report an on-line two-dimensional system constructed by counter-current chromatography (CCC) coupling with preparative high-performance liquid chromatography (prep-HPLC) for the separation and purification of polar natural products. The CCC was used as the first dimensional isolation column, where an environmental friendly polar two-phase solvent system of isopropanol and 16% sodium chloride aqueous solution (1:1.2, v/v) was introduced for low toxicity and favorable resolution.

On-line comprehensive two-dimensional normal-phase liquid chromatography × reversed-phase liquid chromatography for preparative isolation of Peucedanum praeruptorum.

A new on-line comprehensive preparative two-dimensional normal-phase liquid chromatography × reversed-phase liquid chromatography (2D NPLC × RPLC) system was developed for the separation of complicated natural products. It was based on the use of a silica gel packed medium-pressure column as the first dimension and an ODS preparative HPLC column as the second dimension. The two dimensions were connected with normal-phase (NP) and reversed-phase (RP) enrichment units, involving a newly developed airflow assisted adsorption (AAA) technique.

Two-dimensional countercurrent chromatography×high performance liquid chromatography with heart-cutting and stop-and-go techniques for preparative isolation of coumarin derivatives from Peucedanum praeruptorum Dunn.

Pure compounds isolated from complex natural plants are important for drug discovery. This study describes a novel two-dimensional hyphenation of counter-current chromatography and high-performance liquid chromatography (2D CCC×HPLC) with heart-cutting and stop-and-go techniques for preparative isolation of multiple targets components from Peucedanum praeruptorum Dunn (Umbelliferae) crude extracts in a single step. The CCC and HPLC were hyphenated via a 4-port valve equipped at the post-end of the CCC column, to heart cut the impure fractions to the 2nd dimensional HPLC for further separation.

Using positive-ion electrospray ionization mass spectrometry and H/D exchange study phosphoryl group transfer reactions involved in amino acid ester isopropyl phosphoramidates of Brefeldin A.

As mini-chemical models, amino acid ester isopropyl phosphoramidates of Brefeldin A (compounds 2a-2d) were synthesized and investigated by electrospray ionization tandem mass spectrometry in combination with H/D exchange. To further confirm the fragments's structures, off-line Fourier transform resonance tandem mass spectrometry (FT-ICR-MS/MS) was also performed. The fragmentation rules of compounds 2a-2d have been summarized and the plausible schemes for the fragmentation pathways were proposed.

Diethyl [(4-nitrobenzamido)(phen-yl)meth-yl]phospho-nate.

In the title compound, C18H21N2O6P, the dihedral angle between the benzene and phenyl rings is 85.1 (2)°. In the crystal, mol-ecules are linked via pairs of N-H⋯O(=P) hydrogen bonds, forming inversion dimers with graph-set notation R 2 (2)(10).