Precise separation of lysine-specific demethylase 1 inhibitors from Corydalis yanhusuo using multi-mode counter-current chromatography guided by virtual screening

Rapidly screening of pancreatic lipase inhibitors from Clematis tangutica using affinity ultrafiltration-HPLC-QTOFMS technique combined with targeted separation, in vitro validation, and molecular docking

INTRODUCTION

Screening of novel pancreatic lipase inhibitors from complex natural products is a meaningful task.

OBJECTIVES

Through accurately screening and separating pancreatic lipase inhibitors from Clematis tangutica (C. tangutica), to discover new leading compounds for slimming and accelerate the development and utilization of Tibetan medicine resources.

METHODS

An integrated strategy that combines affinity ultrafiltration and high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (AU-HPLC-QTOFMS), targeted separation, in vitro validation, and molecular docking was developed to screen pancreatic lipase inhibitors from C. tangutica. The AU-HPLC-QTOFMS technique was performed to fish for the potential active substances. Macroporous resin, preparative liquid chromatography, and high-speed countercurrent chromatography were implemented for the accurate and targeted separation of active compounds. The inhibitory activities of target compounds to pancreatic lipase were detected by the inhibition experiments in vitro. The binding affinities and binding sites were analyzed using molecular docking.

RESULTS

A total of eleven kinds of pancreatic lipase inhibitory substances were screened from C. tangutica. Seven triterpenoid saponins were screened for the first time as lipase inhibitors and successfully prepared with purities higher than 97%. Tanguticoside B, clematangoticoside J, hederoside H1, and rutin showed stronger inhibitory effects with IC50 values of 1.539 ± 0.048, 1.661 ± 0.092, 1.793 ± 0.069, and 1.792 ± 0.094 mmol/l. Moreover, they have the lowest ΔG values of -10.84, -9.97, -10.87, and -9.39 kcal/mol to pancreatic lipase.

CONCLUSION

The integrated strategy using AU-HPLC-QTOFMS, targeted separation, in vitro validation, and molecular docking was feasible for rapidly screening and directionally isolating pancreatic lipase inhibitors from C. tangutica.

A Quinquennial Review of Potent LSD1 Inhibitors Explored for the Treatment of Different Cancers, with Special Focus on SAR Studies

Cancer bears a significant share of global mortality. The enzyme Lysine Specific Demethylase 1 (LSD1, also known as KDM1A), since its discovery in 2004, has captured the attention of cancer researchers due to its overexpression in several cancers like acute myeloid leukaemia (AML), solid tumours, etc. The Lysine Specific Demethylase (LSD1) downregulation is reported to have an effect on cancer proliferation, migration, and invasion. Therefore, research to discover safer and more potent LSD1 inhibitors can pave the way for the development of better cancer therapeutics. These efforts have resulted in the synthesis of many types of derivatives containing diverse structural nuclei. The present manuscript describes the role of Lysine Specific Demethylase 1 (LSD1) in carcinogenesis, reviews the LSD1 inhibitors explored in the past five years and discusses their comprehensive structural activity characteristics apart from the thorough description of LSD1. Besides, the potential challenges, opportunities, and future perspectives in the development of LSD1 inhibitors are also discussed. The review suggests that tranylcypromine derivatives are the most promising potent LSD1 inhibitors, followed by triazole and pyrimidine derivatives with IC₅₀ values in the nanomolar and sub-micromolar range. A number of potent LSD1 inhibitors derived from natural sources like resveratrol, protoberberine alkaloids, curcumin, etc. are also discussed. The structural-activity relationships discussed in the manuscript can be exploited to design potent and relatively safer LSD1 inhibitors as anticancer agents.

Two-dimensional chromatography in screening of bioactive components from natural products

INTRODUCTION

Screening and analysis of bioactive components from natural products is a fundamental part of new drug development and innovation. Two-dimensional (2D) chromatography has been demonstrated to be an effective method for screening and preparation of specific bioactive components from complex natural products.

OBJECTIVE

To collect details of application of 2D chromatography in screening of natural product bioactive components and to outline the research progress of different separation mechanisms and strategies.

METHODOLOGY

Three screening strategies based on 2D chromatography are reviewed, including traditional separation-based screening, bioactivity-guided screening and affinity chromatography-based screening. Meanwhile, in order to cover these aspects, selections of different separation mechanisms and modes are also presented.

RESULTS

Compared with traditional one-dimensional (1D) chromatography, 2D chromatography has unique advantages in terms of peak capacity and resolution, and it is more effective for screening and identifying bioactive components of complex natural products.

CONCLUSION

Screening of natural bioactive components using 2D chromatography helps separation and analysis of complex samples with greater targeting and relevance, which is very important for development of innovative drug leads.

A Strategy for Pinpointing Natural Bioactive Components Using Two-Dimensional Bioassay Profilings Combined with Comprehensive Two-Dimensional Countercurrent Chromatography × High-Performance Liquid Chromatography

Inspired by the interpretation of two-dimensional (2D) nuclear magnetic resonance spectra, an efficient strategy was proposed for pinpointing bioactive components from complex natural products. An off-line comprehensive countercurrent chromatography (CCC) × high-performance liquid chromatography (HPLC) was employed to achieve a 2D chemical chromatogram, and 2D bioassay profilings were obtained from bioassays of the eluent of the first dimension (¹D) CCC and the eluent of the second dimension (²D) HPLC. Then 2D chemical chromatograms and 2D bioassay profilings were matched for pinpointing bioactive natural components from complex matrices. Thus, bioactive components in a complex matrix could be efficiently analyzed, separated, and bioactivity-determined. This experimental scheme was successfully demonstrated with a traditional medicinal herb Polygonum cuspidatum Sieb. et Zucc. The feasibility of this 2D strategy was verified with tyrosinase inhibition assay, α-glucosidase inhibition assay, DPPH radical scavenging assay, and ABTS^•+ decolorization assay. Eight natural inhibitors were successfully pinpointed and identified from P. cuspidatum. Both pieceid-2″-O-gallate (10) and vanicoside B (20) were screened and identified as natural tyrosinase inhibitors for the first time. Meanwhile, vanicoside B (20) was also found as the strongest α-glucosidase inhibitor among all the isolated components. Most of the compounds exhibited much higher radical scavenging activities. Compared with traditional methodology based on one-dimensional chromatographic separation, the present 2D strategy would be more precise, efficient, and convenient to screen and separate bioactive compounds from complex matrices.

The separation regularity of the three-phase solvent system of counter-current chromatography based on polarity parameter modeling

The three-phase solvent system of counter-current chromatography can separate compounds with a wide range of polarity, but there is no study of its separation regularity. Therefore, in this work, the separation regularity of the three-phase solvent system was initially investigated from the perspective of solvent polarities and compound polarities. The standard compounds covering a wide polarity range were selected, and three-phase solvent systems, n-hexane/methyl acetate/acetonitrile/water, and n-hexane/methyl tert-butyl ether/acetonitrile/water were used for modeling. The results showed that in the three-phase solvent system, the partition coefficient for the middle and lower phases (lgK_M/L) increased with increasing logP values in three intervals logP < 0, 0 < logP < 4, and logP > 4. In addition, the partition coefficient for the upper and middle phases (lgK_U/M) between the upper and middle phases of the small polarity compounds increases with increasing logP values. LogP vs lgK_M/L of 7 solvent systems were employed for the smoothing spline fit through a predictive model design of the curve fitting toolbox in MATLAB software, and good results were achieved. LogP versus lgK_M/L for n-hexane/methyl tert-butyl ether/acetonitrile/water solvent systems were used for the second-order power fit, and satisfactory results were obtained. The relationship between polarity parameters and separation case parameters was explored using a heat map approach. The separation regularity of the three-phase solvent system was preliminarily investigated. This regularity study gives hope of assistance to the chemists studying three-phase solvents and counter-current chromatography.

Target separation and antitumor metastasis activity of sesquiterpene-based lysine-specific demethylase 1 inhibitors from zedoary turmeric oil

Lysine-specific histone demethylase 1 (LSD1) was the first histone demethylase identified in epigenetics and has recently emerged as an attractive therapeutic target for treating tumors. To date, almost all reported LSD1 inhibitors have been chemosynthesized; however, natural products possess pharmacological and biological activity and can be sources for drug development. Here, we established a target separation countercurrent chromatography technique to isolate LSD1 inhibitors from zedoary turmeric oil. Four sesquiterpene-based LSD1 inhibitors were efficiently obtained with an inhibition ratio equal to or less than that of the positive control drug. Compound 2 showed the most potent inhibitory activity, with a half-maximal inhibitory concentration of 3.97 μM, and was further tested to determine its ability to inhibit LSD1 and its antitumor metastatic effects in MDA-MB-231 cells. These four compounds are the first sesquiterpene-based natural LSD1 inhibitors to be characterized. Our findings provide a new molecular framework for studying LSD1 inhibitors and offer a template for designing more sesquiterpene-based LSD1 inhibitors with potential antitumor activity.

Analytical, Preparative, and Industrial-Scale Separation of Substances by Methods of Countercurrent Liquid-Liquid Chromatography

Countercurrent liquid-liquid chromatographic techniques (CCC), similar to solvent extraction, are based on the different distribution of compounds between two immiscible liquids and have been most widely used in natural product separations. Due to its high load capacity, low solvent consumption, the diversity of separation methods, and easy scale-up, CCC provides an attractive tool to obtain pure compounds in the analytical, preparative, and industrial-scale separations. This review focuses on the steady-state and non-steady-state CCC separations ranging from conventional CCC to more novel methods such as different modifications of dual mode, closed-loop recycling, and closed-loop recycling dual modes. The design and modeling of various embodiments of CCC separation processes have been described.