Hypercohones A-C,acylphloroglucinol derivatives with homo-adamantane cores from Hypericum cohaerens

Three new homo-adamantanyl type natural products were derived from polyprenylated polycyclic acylphloroglucinol.Hypercohones A-C(1-3),along with five other known hypercohones(4-8),were isolated from the aerial parts of Hypericum cohaerens.The structures of 1-3 were elucidated on the basis of comprehensive spectroscopic analysis.The inhibitory activities of these isolates against five human cancer cell lines in vitro were tested.

Sterols and Terpenoids from Viburnum odoratissimum

A new stigmasterol type natural product,viburodorol A(1),along with eleven known sterols and terpenoids(2–12),were isolated from the aerial parts of Viburnum odoratissimum.The structure of 1 was elucidated on the basis of comprehensive spectroscopic analysis.It’s noteworthy that compound 2,the major constituent of this plant,can signifi-cantly stimulate glucose absorption in insulin resistant HepG2 cells without affecting cell viability.Furthermore,this compound can also restore the glucose absorption in DXMS-induced insulin resistant 3T3-L1 cells.

A Triterpenoid Inhibited Hormone-Induced Adipocyte Differentiation and Alleviated Dexamethasone-Induced Insulin Resistance in 3T3-L1 adipocytes

6a-Hydroxylup-20(29)-en-3-on-28-oic acid(1),a natural triterpenoid,was found to possess the ability in a dose-dependent manner inhibiting hormone-induced adipocyte differentiation in 3T3-L1 preadipocytes,and restoring glucose consuming ability in dexamethasone(DXM)-induced insulin resistant 3T3-L1 adipocytes.Compound 1 was also found to ameliorate DXM-induced adipocyte dysfunction in lipolysis and adipokine secretion.Mechanistic studies revealed that 1 inhibited adipocyte differentiation in 3T3-L1 preadipocytes via down-regulating hormone-stimulated gene transcription of peroxisome proliferator-activated receptor c and CCAAT-enhancer-binding protein alpha which are key factors in lipogenesis,and restored DXM-impaired glucose consuming ability in differentiated 3T3-L1 adipocytes via repairing insulin signaling pathway and activating down-stream signaling transduction by phosphorylation of signaling molecules PI3K/p85,Akt2 and AS160,thus leading to increased translocation of glucose transporter type 4 and transportation of glucose.

Effects of Traditional Chinese Medicinal Plants on Antiinsulin Resistance Bioactivity of DXMS-Induced Insulin Resistant HepG2 Cells

Medicinal plants have a long history of use in China to treat diabetic symptoms.Ancient Chinese medical manuscripts and ethnobotanical surveys document plant remedies that continue to be actively used in China for the treatment of diabetic symptoms.Based on a systematic ancient Chinese medical manuscripts review in combination with ethnobotanical survey,16 medicinal plants for the traditional treatment of diabetic symptoms were identified for the evaluation of anti-insulin resistance bioactivity.The biological activity of 16 medicinal plants was tested on dexamethasone(DXMS)-induced insulin resistant HepG2 cells.The result shows that 11 of the 16 medicinal plants enhanced glucose uptake of DXMS-induced insulin resistant HepG2 cells,thereby demonstrating their ability to increase insulin sensitivity,other five medicinal plants including Astragalus membranaceus were found ineffective.The study shows that ancient Chinese medical manuscripts and ethnobotanical surveys on plants for the prevention and treatment of diabetic symptoms provide a promising knowledge base for drug discovery to mitigate the global diabetes epidemic.

Hypercohones D–G,New Polycyclic Polyprenylated Acylphloroglucinol Type Natural Products from Hypericum cohaerens

Four new polycyclic polyprenylated acylphloroglucinol type metabolites,hypercohones D–G(1–4),along with four known analogues(5–8),were isolated from the aerial parts of Hypericum cohaerens.The structures of these isolates were elucidated by extensive spectroscopic methods.The inhibitory activities of these isolates against five human cancer cell lines in vitro were also tested.

α-Glucosidase inhibitive diarylheptanoids from Ottelia acuminata var.acuminata,a traditional vegetable of Bai Nationality in Yunnan

Diabetes is an urgent health issue characterized by ethnic and regional variations,and is inseparable from the differ-ent dietary habits.It is worthy to note that the incidence of diabetes in Bai nationality has been reported to be much lower than Han in China.As a daily vegetable of Bai,the phytochemical and antidiabetic study of Ottelia acuminata var.acuminata had not been carried out.In this study,41 metabolites with diverse diarylheptanoid(six new ones,Otteacumienes A-F),flavone,sesquiterpenoid,coumarin,lignan,polyacetylene,and alkaloid skeletons were charac-terized from O.acuminata var.acuminata.Among them,the racemic nature of 3 was characterized by chiral resolution and calculated ECD methods.The biological study revealed diarylheptanoids showed significantα-glucosidase inhibi-tory activities with 5 as the most effective one(60-fold stronger than acarbose).Molecular docking studies indicated that these structures have different binding cavities with acarbose.This study demonstrated that O.acuminata var.acuminata might correlated with the low incidence diabetes of Bai and the diarylheptanoids may have potential therapeutic value for diabetes mellitus.