Investigating the Effects and Mechanisms of Cyclomorusin on Osteoclasts in a High Glucose Environment

Diabetes mellitus is an endocrine disease characterized by prolonged hyperglycemia. Prolonged high blood sugar levels interfere with the differentiation and maturation process of OBs and OCs, leading to the onset of osteoporosis. However, OCs differentiation and maturation is a complex regulatory process. In this study, we used a co-culture system of RAW264.7 and MC3T3-E1 cells under HG concentration to explore the effect of CYM on OCs in a HG environment. The effects of CYM on the formation and function of OCs were observed using TRAP-positive cell counts and bone resorption pits. Then, mRNA and protein expression levels of OCs-related genes were detected by real-time qPCR and western blotting. The results showed that CYM had an inhibitory effect on OCs differentiation and bone resorption, reduced mRNAs expression of OCs-associated genes, and downregulated RANKL/RANK/TRAF6 pathway that mediates OCs differentiation. CYM could be a promising natural compound against diabetic osteoporosis.

Synthesis and Activity Evaluation of Vinpocetine-Derived Indole Alkaloids

This study focuses on the synthesis of novel vinpocetine derivatives (2-25) and their biological evaluation. The chemical structures of the synthesized compounds were fully characterized using techniques such as 1H NMR, 13C NMR, and HRMS. The inhibitory activity of the synthesized compounds on PDE1A was evaluated, and the results revealed that compounds 3, 4, 5, 12, 14, 21, and 25 exhibited superior inhibitory activity compared to vinpocetine. Compound 4, with a para-methylphenyl substitution, showed a 5-fold improvement in inhibitory activity with an IC50 value of 3.53 ± 0.25 μM. Additionally, compound 25, with 3-chlorothiazole substitution, displayed an 8-fold increase in inhibitory activity compared to vinpocetine (IC50 = 2.08 ± 0.16 μM). Molecular docking studies were conducted to understand the binding models of compounds 4 and 25 within the active site of PDE1A. The molecular docking study revealed additional binding interactions, such as π-π stacking and hydrogen bonding, contributing to the enhanced inhibitory activity and stability of the ligand-protein complexes. Overall, the synthesized vinpocetine derivatives demonstrated promising inhibitory activity on PDE1A, and the molecular docking studies provided insights into their binding modes, supporting further development of these compounds as potential candidates for drug research and development.

Synthesis and Antiviral and Antitumor Activities of Novel 18β-Glycyrrhetinic Acid Derivatives

A series of novel derivatives of 18β-glycyrrhetinic acid (GA) were synthesized by introducing aromatic or heterocyclic structures to extend the side chain, thereby enhancing their interaction with amino acid residues in the active pocket of the target protein. These compounds were structurally characterized using 1H NMR, 13C NMR, and HRMS. The compounds were subsequently evaluated for their inhibitory effects on HIV-1 protease and cell viability in the human cancer cell lines K562 and HeLa and the mouse cancer cell line CT26. Towards HIV-1 protease, compounds 28 and 32, which featured the introduction of heterocyclic moieties at the C3 position of GA, exhibited the highest inhibition, with inhibition rates of 76% and 70.5%, respectively, at 1 mg/mL concentration. Further molecular docking suggests that a 3-substituted polar moiety would be likely to enhance the inhibitory activity against HIV-1 protease. As for the anti-proliferative activities of the GA derivatives, incorporation of a thiazole heterocycle at the C3- position in compound 29 significantly enhanced the effect against K562 cells with an IC50 value of 8.86 ± 0.93 µM. The introduction of electron-withdrawing substituents on the C3-substituted phenyl ring augmented the anti-proliferative activity against Hela and CT26 cells. Compound 13 exhibited the highest inhibitory activity against Hela cells with an IC50 value of 9.89 ± 0.86 µM, whereas compound 7 exerted the strongest inhibition against CT26 cells with an IC50 value of 4.54 ± 0.37 µM. These findings suggest that further modification of GA is a promising path for developing potent novel anti-HIV and anticancer therapeutics.

Identification of Flavonoids from Scutellaria barbata D. Don as Inhibitors of HIV-1 and Cathepsin L Proteases and Their Structure-Activity Relationships

Scutellaria barbata D. Don (SB, Chinese: Ban Zhi Lian), a well-known medicinal plant used in traditional Chinese medicine, is rich in flavonoids. It possesses antitumor, anti-inflammatory, and antiviral activities. In this study, we evaluated the inhibitory activities of SB extracts and its active components against HIV-1 protease (HIV-1 PR) and SARS-CoV2 viral cathepsin L protease (Cat L PR). UPLC/HRMS was used to identify and quantify the major active flavonoids in different SB extracts, and fluorescence resonance energy transfer (FRET) assays were used to determine HIV-1 PR and Cat L PR inhibitions and identify structure-activity relationships. Molecular docking was also performed, to explore the diversification in bonding patterns of the active flavonoids upon binding to the two PRs. Three SB extracts (SBW, SB30, and SB60) and nine flavonoids inhibited HIV-1 PR with an IC₅₀ range from 0.006 to 0.83 mg/mL. Six of the flavonoids showed 10~37.6% inhibition of Cat L PR at a concentration of 0.1 mg/mL. The results showed that the introduction of the 4'-hydroxyl and 6-hydroxyl/methoxy groups was essential in the 5,6,7-trihydroxyl and 5,7,4'-trihydroxyl flavones, respectively, to enhance their dual anti-PR activities. Hence, the 5,6,7,4'-tetrahydroxyl flavone scutellarein (HIV-1 PR, IC₅₀ = 0.068 mg/mL; Cat L PR, IC₅₀ = 0.43 mg/mL) may serve as a lead compound to develop more effective dual protease inhibitors. The 5,7,3',4'-tetrahydroxyl flavone luteolin also showed a potent and selective inhibition of HIV-1 PR (IC₅₀ = 0.039 mg/mL).

Fischer's base-triggered formal (3+2) cycloadditions with 3-isothiocyanato oxindoles as acceptor-donor synthons

Herein, previously unreported Fischer's base reactants serving as useful 2C building blocks in (3+2) cycloaddition reactions to build a library of bispiro[Fischer's base-oxindole] hybrids are described. These structurally intriguing products containing three adjacent quaternary stereocentres were smoothly afforded in up to 82% yield and >20 : 1 dr under catalyst-free conditions. Notably, the present protocol firstly employs 3-isothiocyanato oxindole serving as an acceptor and then as a donor in the formal (3+2) cycloadditions, allowing practical, straightforward access to structurally diverse cycloadducts. This work expands the applicability scope of 3-isothiocyanato oxindoles, which have been limited to behaving as donor/acceptor-based synthons in cycloadditions in previous work.

Catalytic asymmetric Michael/cyclization reaction of 3-isothiocyanato thiobutyrolactone: an approach to the construction of a library of bispiro[pyrazolone-thiobutyrolactone] skeletons

Here, we demonstrate the first example of 3-isothiocyanato thiobutyrolactone serving as a useful building block in the Michael/cyclization reaction with alkylidene pyrazolones for the enantioselective construction of optically active structural bispiro[pyrazolone-thiobutyrolactone] skeletons containing three contiguous stereocenters with two spiroquaternary stereocenters. These products were smoothly afforded in up to 90% yield, >20 : 1 dr and >99% ee with chiral squaramide as the catalyst under mild conditions. Notably, this is also the first example of the merger of a spirocyclic pyrazolone scaffold with a spirocyclic thiobutyrolactone scaffold, potentially useful in medicinal chemistry.

Highly stereoselective synthesis of spirocyclopropylthiooxindoles and biological evaluation

We present a novel highly stereoselective Rh-catalyzed cyclopropanation of diazothiooxindoles with a broad range of α-functionalized styrenes, enabling facile access of chiral spirocyclopropylthiooxindoles in high to excellent enantiomeric excess.

Diastereoselective construction of a library of structural bispiro[butyrolactone/valerolactone-pyrrolidine-indanedione] hybrids via 1,3-dipolar cycloaddition reactions

Herein, a highly efficient strategy that allows the diversity synthesis of a library of structural bispiro[butyrolactone-pyrrolidine-indanedione] hybrids is achieved effectively by means of 1,3-dipolar cycloadditions of α,β-unsaturated butyrolactones/valerolactones as dipolarophiles...

Regio- and stereoselective synthesis and evaluation of densely functionalized bispiro[oxindole-isoxazole-indandione] hybrids as anticancer agents

This is the combination of three key pharmacophores through bispiro quaternary carbon atoms and evaluation of their anticancer activity.

Catalytic enantioselective construction of vicinal quaternary carbon stereocenters

This review summarizes the advances in the catalytic enantioselective construction of vicinal quaternary carbon stereocenters, introduces major synthetic strategies and discusses their advantages and limitations, highlights the application of known protocols in the total synthesis of natural products, and outlines the synthetic opportunities.

This review summarizes the advances in catalytic enantioselective construction of vicinal quaternary carbon stereocenters, introduces major synthetic strategies and discusses their advantages and limitations, and outlines the synthetic opportunities.

Synthesis and biological evaluation of Vinpocetine derivatives

A new series of Vinpocetine derivatives were synthesized and evaluated for their inhibitory activity on PDE1A in vitro. Seven compounds with higher inhibitory activity were selected for surface plasmon resonance (SPR) binding experiments. Compared with Vinpocetine, these high potency compounds presented a higher binding affinity with PDE1A, which was consistent with inhibitory activity. After further screening, compounds 5, 7, 21, 34 and Vinpocetine were selected to examine the vasorelaxant effects on endothelium-intact rat thoracic aortic rings. The study suggested that the effects of compounds 7 and 21 were the most significant with the maximum value of 93.46 ± 0.77% and 92.90 ± 0.78% (n = 5) at a concentration of 100 μM respectively. Based on these studies, compounds 7 and 21 were considered for further development as hit compounds.

Catalytic enantioselective synthesis using carbon dioxide as a C1 synthon

This review summarizes the advances in catalytic enantioselective reactions using CO₂ as a C1 synthon, introduces strategies and discusses advantages and limitations, highlights the application, and outlines the synthetic opportunities.

A highly efficient and eco-friendly method for the synthesis of 1,3-indandione ring-fused 3-oxindoles bearing two contiguous quaternary stereocenters via an aldol reaction in aqueous media

The synthesis and antitumor activity evaluation of 1,3-indandione ring-fused 3-oxindoles.

[Studies on cultivation techniques for Rehmannia glutinosa Libosch. in summer]

Through many years' research, a set of cultivation techniques for Rehmannia glutinosa in summer has been found out as "selecting necks in autumn; growing seedlings with plastic films in early spring; culturing around summer solstice and reaping after autumn". A Study has also been made on the scope feasible for spreading the application of these techniques.