Tetramethylkaempferol

Structural requirements of flavonoids for the adipogenesis of 3T3-L1 cells.[Pubmed:21493073]

Bioorg Med Chem. 2011 May 1;19(9):2835-41.

To search for a new class of antidiabetic compounds, effects of 44 flavonoids on the adipogenesis of 3T3-L1 cells were examined. Among them, 3,4',7-trimethylkaempferol, Tetramethylkaempferol, and pentamethylquercetin concentration-dependently enhanced the accumulation of triglyceride, a marker of adipogenesis. With regard to structural requirements of flavonoids for the activity, it was fond that: (1) most flavonoids having hydroxy groups lacked the effect; (2) flavonols with methoxy groups showed stronger effects particularly those with a methoxy group at the 3-position; and (3) a methoxy group of flavonols at the B ring was also important. 3,4',7-Trimethylkaempferol, Tetramethylkaempferol, and pentamethylquercetin significantly increased the amount of adiponectin released into the medium and the uptake of 2-deoxyglucose into the cells. Furthermore, Tetramethylkaempferol and pentamethylquercetin also increased mRNA levels of adiponectin, glucose transporter 4 (GLUT4), and fatty acid-binding protein (aP2). Both compounds also increased the mRNA levels of peroxisome proliferator-activated receptor (PPAR)gamma2 and CCAAT/enhancer-binding protein (C/EBP)alpha, beta, and/or delta, although, different from troglitazone, they did not activate PPARgamma directly in a nuclear receptor cofactor assay.

Search for new type of PPARgamma agonist-like anti-diabetic compounds from medicinal plants.[Pubmed:24882400]

Biol Pharm Bull. 2014;37(6):884-91.

Potent ligands of peroxisome proliferator-activated receptor gamma (PPARgamma) such as thiazolidinediones (pioglitazone, troglitazone, etc.) improve insulin sensitivity by increasing the levels of adiponectin, an important adipocytokine associated with insulin sensitivity in adipose tissue. Several constituents from medicinal plants were recently reported to show PPARgamma agonist-like activity in 3T3-L1 cells, but did not show agonistic activity at the receptor site different from thiazolidinediones. Our recent studies on PPARgamma agonist-like constituents, such as hydrangenol and hydrangeic acid from the processed leaves of Hydrangea macrophylla var. thunbergii, piperlonguminine and retrofractamide A from the fruit of Piper chaba, and Tetramethylkaempferol and pentamethylquercetin from the rhizomes of Kaempferia parviflora, are reviewed.

Antioxidant caffeic acid derivatives from leaves of Parthenocissus tricuspidata.[Pubmed:15089035]

Arch Pharm Res. 2004 Mar;27(3):300-4.

Five caffeic acid derivatives; methyl ester of caffeoylglycolic acid (1), dimethyl ester of caffeoyltartaric acid (2), dimethyl ester of caffeoyltartronic acid (3), monomethyl ester of caffeoyltartronic acid (4), methyl ester of caffeic acid (5), and some other secondary metabolites including; quercetin, quercetin 3-O-beta-D-glucuronide methyl ester, kaempferol, 3,5,7,4'-O-Tetramethylkaempferol, beta-sitosterol glucoside, 2alpha-hydroxyursolic acid and 2,24-dihydroxyursolic acid, have been isolated and characterized. All the isolated compounds were characterized with the help of NMR spectroscopy and mass spectrometry. Structure of compound 3 was also confirmed by a single X-ray crystallographic technique. Isolates were evaluated for antioxidant activities and most of the tested compounds were found to be potent in DPPH free radical scavenging (IC50 = 4.56-14.17 microg/mL) and superoxide anion scavenging (IC50 = 0.58-7.39 microg/mL) assays.