Isoprenylated phenolic compounds with tyrosinase inhibition from Morus nigra.

A new isoprenylated sanggenon-type flavanone, nigrasin K (1), together with three known analogs (2-4) and five known Diels-Alder adducts (5-9), were isolated from the twigs of Morus nigra. Their structures were elucidated by spectroscopic methods. Sanggenon M (2), chalcomoracin (5), sorocein H (6), kuwanon J (7), sanggenon C (8), and sanggenon O (9) showed significant inhibitory effects on mushroom tyrosinase.

Inhibitory Effects of (2'R)-2',3'-dihydro-2'-(1-hydroxy-1-methylethyl)-2,6'-bibenzofuran-6,4'-diol on Mushroom Tyrosinase and Melanogenesis in B16-F10 Melanoma Cells.

(2'R)-2',3'-Dihydro-2'-(1-hydroxy-1-methylethyl)-2,6'-bibenzofuran-6,4'-diol (DHMB) is a natural compound extracted from Morus notabilis. It was found that DHMB acts as a competitive inhibitor against mushroom tyrosinase with a Ki value of 14.77 μM.

Benzbromarone, an old uricosuric drug, inhibits human fatty acid binding protein 4 in vitro and lowers the blood glucose level in db/db mice.

Aim: Fatty acid-binding protein 4 (FABP4) plays an important role in maintaining glucose and lipid homeostasis. The aim of this study was to find new inhibitors of FABP4 for the treatment of type 2 diabetes.

Methods: Human FABP4 protein was expressed, and its inhibitors were detected in 1,8-ANS displacement assay.

[Progress of anti-tumor study based on BRAF].

BRAF is one of the most important pro-oncogenes, which is mutated in approximately 8% of human tumors. The most common BRAF mutation is a valine-to-glutamate transition (V600E) that is expressed primarily in melanoma, colorectal cancer and thyroid carcinoma. MEK/ERK is constitutively activated in the cells expressing BRAFV600E, leading to tumor development, invasion, and metastasis.

2-Arylbenzofuran and tyrosinase inhibitory constituents of Morus notabilis.

Phytochemical investigation of the stem of Morus notabilis led to the isolation and characterization of 10 compounds of 2-arylbenzofurans (1-10), including two new compounds, (2'R)-2',3'-dihydro-2'-(1-hydroxy-1-methylethyl)-2,6'-bibenzofuran-6,4'-diol (1) and 5,6-dimethoxy-2-(3-hydroxy-5-methoxyphenyl)benzofuran (2). Moracins O (6) and P (10) showed inhibitory effects on mushroom tyrosinase with IC₅₀ values being lower than that of kojic acid.

New isoprenylated flavones and stilbene derivative from Artocarpus hypargyreus.

Three new isoprenylated flavones, hypargyflavones A-C (1-3, resp.), and one novel stilbene derivative, hypargystilbene A (4), together with seven known compounds, 5-11, were isolated from the stems of Artocarpus hypargyreus Hance. The structures were elucidated by spectroscopic methods.

Pharmacological inhibition of diacylglycerol acyltransferase 1 reduces body weight gain, hyperlipidemia, and hepatic steatosis in db/db mice.

Aim: To test whether pharmacological inhibition of Diacylglycerol acyltransferase 1 (DGAT1) by a small-molecule inhibitor H128 can improve metabolism disorders in leptin receptor-deficient db/db mice.

Methods: To investigate the effect of H128 on intestinal fat absorption,db/db mice were acutely given a bolus of corn oil by gavage. The mice were further orally administered H128 (3 and 10 mg/kg) for 5 weeks.

New isoprenylated 2-arylbenzofurans and pancreatic lipase inhibitory constituents from Artocarpus nitidus.

Two new isoprenylated 2-arylbenzofurans, artonitidin A (=(2'R)-2',3'-dihydro-2'-(1-hydroxy-1-methylethyl)-5',7-bis(3-methylbut-2-en-1-yl)-2,4'-bi-1-benzofuran-6,6'-diol; and artonitidin B (=5-[6-hydroxy-7-(3-methylbut-2-en-1-yl)-1-benzofuran-2-yl]-4-(3-methylbut-2-en-1-yl)benzene-1,3-diol; together with 14 known compounds, were isolated from the stems of Artocarpus nitidus Trec. The structures were elucidated by spectroscopic methods. Norartocarpin, cudraflavone C, brosimone I, artotonkin, albanin A, and artopetelin M showed inhibitory effects on pancreatic lipase with IC(50) values ranging from 1.