Regiospecific Profiles of Fatty Acids in Triacylglycerols and Phospholipids from Adzuki Beans (Vigna angularis)

Regiospecific distributions of fatty acids (FA) of triacylglycerols (TAG) and phospholipids (PL) isolated from five cultivars of adzuki beans (Vigna angularis) were investigated. The lipids comprised mainly PL (72.2-73.4 wt-%) and TAG (20.6-21.9 wt-%), whilst other components were detected in minor proportions (0.1-3.4 wt-%). The principal profiles of the FA distribution in the TAG and PL were evident in the beans among the five cultivars: unsaturated FA were predominantly distributed in the sn-2 position, whilst saturated FA primarily occupied the sn-1 or the sn-3 position in the these lipids. The results would be useful information to both producers and consumers for manufacturing traditional adzuki confectionaries such as wagashi in Japan

3-O-Acyl-epicatechins Increase Glucose Uptake Activity and GLUT4 Translocation through Activation of PI3K Signaling in Skeletal Muscle Cells

Tea catechins promote glucose uptake in skeletal muscle cells. In this study, we investigated whether the addition of an acyl group to the C-3 position of catechins to generate 3-O-acyl-catechins promoted glucose uptake in L6 myotubes. 3-O-Myristoyl-(-)-epicatechin (EC-C14) and 3-O-palmitoyl-(-)-epicatechin (EC-C16) promoted glucose uptake and translocation of glucose transporter (GLUT) 4 in the cells. The effect of 3-O-acyl-(-)-epicatechins was stronger than that of (-)-epicatechin (EC), whereas neither 3-O-myristoyl-(+)-catechin (C-C14) nor 3-O-palmitoyl-(+)catechin (C-C16) promoted glucose uptake or GLUT4 translocation as well as (+)-catechin (C). We further investigated an affinity of catechins and 3-O-acyl-catechins to the lipid bilayer membrane by using surface plasma resonance analysis. Maximum binding amounts of EC-C16 and C-C16 to the lipid bilayer clearly increased compared with that of (-)-EC and (+)-C, respectively. We also examined the mechanism of GLUT4 translocation and found EC-C14 and EC-C16 induced the phosphorylation of PI3K, but did not affect phosphorylation of Akt or IR. In conclusion, the addition of an acyl group to the C-3 position of (-)-EC increases its affinity for the lipid bilayer membrane and promotes GLUT4 translocation through PI3K-dependent pathways in L6 myotubes

3-O-Methylfunicone, a Selective Inhibitor of Mammalian Y-Family DNA Polymerases from an Australian Sea Salt Fungal Strain

We isolated a pol inhibitor from the cultured mycelia extract of a fungal strain isolated from natural salt from a sea salt pan in Australia, which was identified as 3-O-methylfunicone by spectroscopic analyses. This compound selectively inhibited the activities of mammalian Y-family DNA polymerases (pols) (i.e., pols η, ι and κ). Among these pols, human pol κ activity was most strongly inhibited, with an IC50 value of 12.5 μM. On the other hand, the compound barely influenced the activities of the other families of mammalian pols, such as A-family (i.e., pol γ), B-family (i.e., pols α, δ and ɛ) or X-family (i.e., pols β, λ and terminal deoxynucleotidyl transferase), and showed no effect on the activities of fish pol δ, plant pols, prokaryotic pols and other DNA metabolic enzymes, such as calf primase of pol α, human immunodeficiency virus type-1 (HIV-1) reverse transcriptase, human telomerase, T7 RNA polymerase, mouse IMP dehydrogenase (type II), human topoisomerases I and II, T4 polynucleotide kinase or bovine deoxyribonuclease I. This compound also suppressed the growth of two cultured human cancer cell lines, HCT116 (colon carcinoma cells) and HeLa (cervix carcinoma cells), and UV-treated HeLa cells exhibited lower clonogenic survival in the presence of inhibitor

Inhibitory effects of vitamin K3 on DNA polymerase and angiogenesis

Vitamins play essential roles in cellular reactions and maintain human health. Recent studies have revealed that some vitamins including D3, B6 and K2 and their derivatives have an anti-cancer effect. As a mechanism, their inhibitory effect on cancer-related angiogenesis has been demonstrated. Vitamin K2 (menaquinones) has an anti-cancer effect in particular for hepatic cancer and inhibits angiogenesis. In the current study, we demonstrated that sole vitamin K3 (menadione) selectively inhibits the in vitro activity of eukaryotic DNA polymerase γ, which is a mitochondrial DNA polymerase, and suppresses angiogenesis in a rat aortic ring model. The anti-angiogenic effect of vitamin K3 has been shown in angiogenesis models using human umbilical vein endothelial cells (HUVECs) with regard to HUVEC growth, tube formation on reconstituted basement membrane and chemotaxis. These results suggest that vitamin K3 may be a potential anti-cancer agent like vitamin K2.This work was supported by the ‘Academic Frontier’ Project for Private Universities (Kobe-Gakuin University), matching fund subsidy from MEXT, 2006-2010, (K.M., H.Y. and Y.M.) and in part by a grant from the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT). K.M. acknowledges a Grant-in-Aid for Young Scientists (B) (No. 18700608) from MEXT. Y.M. also acknowledges a Grant-in-Aid for Young Scientists (A) (No. 19680031) from MEXT, and Grants-in-Aid from the Nakashima Foundation and the Foundation of Oil & Fat Industry, Kaikan, Japan

Effects of Intermediates between Vitamins K2 and K3 on Mammalian DNA Polymerase Inhibition and Anti-Inflammatory Activity

Previously, we reported that vitamin K3 (VK3), but not VK1 or VK2 (=MK-4), inhibits the activity of human DNA polymerase γ (pol γ). In this study, we chemically synthesized three intermediate compounds between VK2 and VK3, namely MK-3, MK-2 and MK-1, and investigated the inhibitory effects of all five compounds on the activity of mammalian pols. Among these compounds, MK-2 was the strongest inhibitor of mammalian pols α, κ and λ, which belong to the B, Y and X families of pols, respectively; whereas VK3 was the strongest inhibitor of human pol γ, an A-family pol. MK-2 potently inhibited the activity of all animal species of pol tested, and its inhibitory effect on pol λ activity was the strongest with an IC50 value of 24.6 μM. However, MK-2 did not affect the activity of plant or prokaryotic pols, or that of other DNA metabolic enzymes such as primase of pol α, RNA polymerase, polynucleotide kinase or deoxyribonuclease I. Because we previously found a positive relationship between pol λ inhibition and anti-inflammatory action, we examined whether these compounds could inhibit inflammatory responses. Among the five compounds tested, MK-2 caused the greatest reduction in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced acute inflammation in mouse ear. In addition, in a cell culture system using mouse macrophages, MK-2 displayed the strongest suppression of the production of tumor necrosis factor (TNF)-α induced by lipopolysaccharide (LPS). Moreover, MK-2 was found to inhibit the action of nuclear factor (NF)-κB. In an in vivo mouse model of LPS-evoked acute inflammation, intraperitoneal injection of MK-2 in mice led to suppression of TNF-α production in serum. In conclusion, this study has identified VK2 and VK3 intermediates, such as MK-2, that are promising anti-inflammatory candidates

Inhibitory Effects of Glycyrrhetinic Acid on DNA Polymerase and Inflammatory Activities

We investigated the inhibitory effect of three glycyrrhizin derivatives, such as Glycyrrhizin (compound 1), dipotassium glycyrrhizate (compound 2) and glycyrrhetinic acid (compound 3), on the activity of mammalian pols. Among these derivatives, compound 3 was the strongest inhibitor of mammalian pols α, β, κ, and λ, which belong to the B, A, Y, and X families of pols, respectively, whereas compounds 1 and 2 showed moderate inhibition. Among the these derivatives tested, compound 3 displayed strongest suppression of the production of tumor necrosis factor-α (TNF-α) induced by lipopolysaccharide (LPS) in a cell-culture system using mouse macrophages RAW264.7 and peritoneal macrophages derived from mice. Moreover, compound 3 was found to inhibit the action of nuclear factor-κB (NF-κB) in engineered human embryonic kidney (HEK) 293 cells. In addition, compound 3 caused greater reduction of 12-O-tetradecanoylphorbol-13-acetate-(TPA-) induced acute inflammation in mouse ear than compounds 1 and 2. In conclusion, this study has identified compound 3, which is the aglycone of compounds 1 and 2, as a promising anti-inflammatory candidate based on mammalian pol inhibition

The biochemical inhibition mode of bredinin-5′-monophosphate on DNA polymerase β

AbstractWe reported previously [T. Horie, Y. Mizushina, M. Takemura, F. Sugawara, A. Matsukage, S. Yoshida, K. Sakaguchi, Int. J. Mol. Med., 1 (1998) 83–90.] that a 5′-monophosphate form (breMP) of bredinin, which has been used clinically as an immunosuppressive drug, selectively suppressed the activities of mammalian DNA polymerase α (pol. α) and β (pol. β). In a preliminary study of the action mode, for pol. β, breMP acted by competing with, unexpectedly, not only the substrate but also with the template-primer. The mode might be attributable to the structure and function of pol. β itself. We therefore investigated the biochemical inhibition mode of pol. β in more detail by using two pol. β fragments which were proteolytically separated into the template-primer-binding domain and the catalytic domain. BreMP inhibited only the catalytic activity of the catalytic domain fragment, and could not bind to the template-primer-binding domain fragment, suggesting that it directly competes with the substrate at its binding site of the catalytic domain, and indirectly, but simultaneously and competitively disturbs the template-primer incorporation into the template-primer-binding domain