Spirohypertones A and B as potent antipsoriatics:Tumor necrosis factor-αinhibitors with unprecedented chemical architectures

Tumor necrosis factor-α(TNF-α)is a promising target for inflammatory and autoimmune diseases.Spirohypertones A(1)and B(2),two unprecedented polycyclic polyprenylated acylphloroglucinols with highly rearranged skeletons,were isolated from Hypericum patulum.The structures of 1 and 2 were confirmed through comprehensive spectroscopic analysis,single-crystal X-ray diffraction and electronic circular dichroism calculations.Importantly,2 showed remarkable TNF-αinhibitory activity,which could protect L929 cells from death induced by co-incubation with TNF-αand actinomycin D.It also demonstrated the ability to suppress the inflammatory response in HaCaT cells stimulated with TNF-α.Notably,in an imiquimod-induced psoriasis murine model,2 restrained symptoms of epidermal hyperplasia associated with psoriasis,presenting anti-inflammatory and antiproliferative effects.This discovery positions 2 as a potent TNF-αinhibitor,providing a promising lead compound for developing an antipsoriatic agent.

Meroterpenoids with Potent Immunosuppressive Activity from Fungus Bipolaris zeicola

Six new meroterpe no ids,bipolarinoids A-F(1-6),and two known congen ers(7-8)were isolated from a soil-derived fungus Bipolaris zeicola.Their structures were elucidated based on extensive spectroscopic techniques(ineluding HRESIMS and ID and 2D NMR data),and the absolute configurations of 1-4 were further confirmed viasingle-crystal X-ray diffraction an alysis and comparis on of experimental electronic circular dichroism(ECD)data.Structurally,compound 1 represents the first case of cochlioquinone derivatives featuring a formaldehyde group at C-11, and compou nd 3 features a rareamino group at C-11.In the immunosuppressive activity assay,compounds 5-8 showed potent inhibitory activity against concanavalin A(ConA)-induced T lymphocyte proliferation with IC50 values of 78.3,81.1,48.3,and 48.0 nmol/L,respectively,which provided promising leads for designing and developing new im-muno suppressive agents to treat auto-immunological diseases.

Hybeanones A and B,Two Highly Modified Polycyclic Polyprenylated Acylphloroglucinols from Hypericum beanii

Hybeanones A and B(1 and 2),two highly oxygenated and rearranged polycyclic polyprenylated acylphloroglucinols(PPAPs),were isolated from the aerial parts of Hypericum beanii.Their structures comprising absolute configurations were elucidated by spectroscopic analysis,single-crystal X-ray diffraction,and quantum chemical calculations.Compounds 1 and 2 are defined by a newly assembled cyclopentanone unit fused to a tricyclic γ-lactone unit via a ketone carbonyl.The breakage of C-1/C-2 linkage via retro-Claisen reaction,attack from C-1 to C-19,and Baeyer-Villiger oxidation at C-1/C-23 bond were presumed to be the key steps in the assembly of 1 and 2.The isolates 1 and 2 showed potential acetylcholinesterase(AchE)inhibitory activities,with IC50 values of 21.34±1.48 and 18.79±2.36μmol/L,respectively.

Polyaspers A and B,the First Ergosterol-Polyether Adducts with Unprecedented 6/6/6/5/5/6/6/6/6 Nonacyclic Architecture from Aspergillus sp.TJ507

Psoriasis is a chronic immune-mediated inflammatory skin disease and the TNF-αis an important therapeutic target of this disease.In our continuous study of bioactive natural products from fungi,the first ergosterol-polyether adducts,polyaspers A(1)and B(2),along with two known ergosterols,(36,5α,6α,22E)-5,6-epoxy-3-hydroxyergosta-8,22-dien-7-one(3)and calvasterol B(4),were iso-lated from Aspergillus sp.TJ507.Structure elucidation was accomplished by extensive spectroscopic analysis and single-crystal X-ray diffraction tests.Polyaspers A and B possessing an unequalled 6/6/6/5/5/6/6/6/6 nonacyclic system,and their biosynthetic path-ways were proposed to include intermolecular cyclization and Diels-Alder reactions.Activity screen of these isolates showed that 1-3 could improve the cell viability in an actinomycin D/TNF-αinduced L929 cells death model,with the EC50 values of 49.85,46.75 and 4.99μmol/L,respectively,and the activity of 3 was even comparable with that of the positive control SPD304.Further bioactive investigations discovered 3 could suppress the inflammatory response simulated with TNF-αin HaCaT cells.In an imiquimod-induced psoriasis murine model,3 significantly restrained the development of psoriasis symptoms and reduced the expression of IL-17 and IL-23,presenting an anti-psoriatic effect.As such,those ergosterol derivatives,might serve as lead compounds for the development of novel TNF-αinhibitory agents in the clinical treatment of psoriasis.