Preparation of glycoside polymer micelles with antioxidant polyphenolic cores using alkylated poly(arbutin)s.

This paper describes the synthesis of long-chain-alkylated poly(arbutin)s (poly(Arb)-R x , where R = alkyl-chain length and x = degree of substitution (DS)) and their aqueous micelle formation. DS was controlled by tailoring the alkyl reagent/main-chain phenol substituent feed ratio. The critical micelle concentrations (CMCs) of poly(Arb)-R x were determined as 1.3-5.2 mg mL-1 by the surface tension method. Introduction of longer alkyl substituents decreased CMC and also decreased aqueous solubility. In DLS measurement, the average micelle diameters were 225-616 nm, and micelle size decreased with increasing DS because of increased stabilization by hydrophobic alkyl substituents. Transmission electron microscopy indicated that mainly wormlike cylindrical micelles were formed, even with highly hydrophilic polymers. The alkylated polymer exhibited no cytotoxicity, and their antioxidant abilities were evaluated by the ß-carotene bleaching method. Only 0.049 mol equivalents of poly(Arb)-C830 to linoleic acid was sufficient to preserve the ß-carotene.

Ca2+-Signal Transduction Inhibitors, Kujiol A and Kujigamberol B, Isolated from Kuji Amber Using a Mutant Yeast.

A podocarpatriene and a labdatriene derivative, named kujiol A [13-methyl-8,11,13-podocarpatrien-19-ol (1)] and kujigamberol B [15,20-dinor-5,7,9-labdatrien-13-ol (2)], respectively, were isolated from Kuji amber through detection with the aid of their growth-restoring activity against a mutant yeast strain ( zds1Δ erg3Δ pdr1Δ pdr3Δ), which is known to be hypersensitive with respect to Ca2+-signal transduction. The structures were elucidated by spectroscopic data analysis. Compounds 1 and 2 are rare organic compounds from Late Cretaceous amber, and the mutant yeast used seems useful for elucidating a variety of new compounds from Kuji amber specimens, produced before the K-Pg boundary.

Prominent differences in leaf fatty acid composition in the F1 hybrid compared with parent trees Larix gmelinii var. japonica and L. kaempferi.

Fatty acid (FA) compositions in leaves were investigated for two families of F(1) hybrids of Larix gmelinii var. japonica x L. kaempferi (F(1)) and their parent clones. Twenty-one FAs, from C(12) to C(32), were found in the leaves of both adult trees and seedlings. The levels of 18:1/(18:2 + 18:3) increased in the order L. kaempferi, F(1), and L. gmelinii var. japonica, with significant differences between L. gmelinii var. japonica and F(1) in adult trees, but these differences were not found in the seedlings. Moreover, in the adult trees, the 18:1/(18:2 + 18:3) levels in the neutral phospholipid fraction and the SigmaC(18)/SigmaC(16), especially in the glycolipid fraction, showed significant differences among the three species. These characteristics are discussed from the viewpoint of lipid synthesis in the endoplasmic reticulum and chloroplasts, and of the activities and substrate specificities in sequential FA desaturation. Linear discriminant analysis suggested that the FA compositions are useable as an index in the identification of hybrid seedlings.

A quinone isolated from the nest of Vespa simillima and its growth-inhibitory effect on rat liver cancer cells.

A biologically active quinone that exhibits a growth-inhibitory effect on rat liver cancer cells was isolated from the nest of a social wasp, Vespa simillima (Vespinae, Vespidae). The structure was unambiguously determined by NMR and synthetic experiments and identified as being 7,8-seco-para-ferruginone. The synthetic quinone showed potent growth-inhibitory effects on rat hepatoma cells (IC50 value=1.9 microM). Morphological analyses of dRLh84 cells using the synthetic compound were tested. Chromatin coagulation was induced by the synthetic compound at 31.6 muM.

Identification of COX inhibitors in the hexane extract of Japanese horse chestnut (Aesculus turbinata) seeds.

Japanese horse chestnut (Aesculus turbinata) seed extract inhibits the activity of cyclooxygenase (COX), but its active constituents have not been identified. In the present study, COX inhibitors were isolated from the hexane extract of this seed by means of 4 steps of liquid chromatography and were identified by gas chromatography/mass spectrometry and nuclear magnetic resonance. The COX inhibitors in the extract of Japanese horse chestnut seeds were identified as linoleic acid, linolenic acid, and oleic acid. Their efficacies were in the following order: linolenic acid = linoleic acid > oleic acid. These active constituents are C18 unsaturated fatty acids; stearic acid, a C18 saturated fatty acid, had no activity. Linolenic acid and linoleic acid had high selectivity toward COX-2 (selectivity index = 10), whereas oleic acid had no selectivity. Considering the efficacy and yield of each fatty acid, linoleic acid may be the principal COX inhibitor in this seed.

Antiinflammatory effect of Japanese horse chestnut (Aesculus turbinata) seeds.

The antiinflammatory effects of Japanese horse chestnut (Aesculus turbinata) seeds were examined in vivo and in vitro. The extract of this seed (HCSE) inhibited croton oil-induced swelling of the mouse concha. HCSE inhibited cyclooxygenase (COX) -1 and -2 activities, but had no effect on 15-lipoxygenase and phospholipase A2 activities. Inhibition of COX-2 occurred at a lower concentration of HCSE than for COX-1. Japanese horse chestnut seeds contain coumarins and saponins, but these chemicals did not inhibit COX activities. These results suggest that the antiinflammatory effect of Japanese horse chestnut seeds is caused, at least partly, by the inhibition of COX. The inhibitor of COX in this seed may be a chemical(s) other than coumarins and saponins.

A diterpene quinone from the bark of Cryptomeria japonica.

A diterpene, cryptoquinone, was isolated from the bark of Cryptomeria japonica, the structure, 7,11,14-trioxoabieta-8,12-diene, was established by spectral analyses and X-ray crystallography. This diterpene quinone showed moderate antifungal activities against Pyricularia orizae and Alternaria alternata, and cytotoxic activity against mouse lymphoid neoplasm (P388) cells with an IC(50) of 0.26 microg/ml.