Kazuhiro Sugamoto

Antimicrobial activity of heartwood components of sugi (Cryptomeria japonica) against several fungi and bacteria

Methanol extract of sawdust of sugi (Cryptomeria japonica) heartwood was fractionated with toluene and n-hexane to give solvent-soluble and solvent-insoluble fractions. The n-hexane-soluble fraction showed the most inhibition activity among the fractions against phytopathogenic microorganisms, namely Fusarium oxysporum, Phytophthora capsici, Pythium splendens, and Ralstonia solanacearum. Sandaracopimarinol and ferruginol, isolated from the n-hexane-soluble fraction, showed moderate antifungal activity against the three fungi and strong antibacterial activity against R. solanacearum. The content of sandaracopimarinol (7.07 g/kg based on the dried sawdust) in the heartwood was about twice that of ferruginol. Sandaracopimarinol and ferruginol strongly inhibited the growth of Gram-positive bacteria but did not show inhibitory action against Gram-negative bacteria except for R. solanacearum. The antibacterial effect of sandaracopimarinol was first found in the present study and was stronger than that of ferruginol.

Silica gel-catalyzed β-O-glucosylation of alcohols with 1,2-anhydro-3,4,6-tri-O-pivaloyl-α-d-glucopyranose

1,2-anhydro-3,4,6-tri-O-pivaloyl-α-d-glucopyranose (1a) was allowed to react with alcohols in the presence of solid acids such as silica gel and zeolite HY, to afford β-O-glucosides stereoselectively. Several natural glucosides were synthesized by the application of the present reaction.

Preparation and Properties of Gelatin-Immobilized β-Glucosidase from Pyrococcus furiosus

Hyperthermostable β-glucosidase from Pyrococcus furiosus was enclosed in gelatin gel by cross-linking with transglutaminase. Gelatin-immobilized β-glucosidase was considerably more thermostable than the native enzyme. Lyophilized immobilisate was stored at 90 °C for 1 month without loss of activity. The immobilized β-glucosidase catalyzed transglucosylation of 5-phenylpentanol with 10.0 equivalent of cellobiose at pH 5.0 and 70 °C for 12 h to afford 5-phenylpentyl β-D-glucopyranoside in 41% yield. The immobilized enzyme was more effective than the native one in transglucosylation. The gelatin-immobilized Pfu-β-glucosidase recovered from the first run of the reaction was reusable on successive runs.

Enantioselective syntheses of 10-oxo-11(E)-octadecen-13-olide and related fatty acid

Abstract The first, and short-step, syntheses of S and R enantiomers of 10-oxo-11( E )-octadecen-13-olide ( 1 ) and its seco-acid 2 , cytotoxic fatty acid derivatives from corn, were achieved from linoleic acid ( 3 ) by the combined use of lipoxygenase-catalyzed asymmetric oxygenation and cobalt porphyrin-catalyzed reduction-oxygenation as key-step reactions.

Facile and general method for preparation of (E)-4-hydroxy-2-alkenals.

A facile one-pot synthesis of (E)-4-hydroxy-2-alkenals such as (E)-4-hydroxy-2-nonenal, (E)-4-hydroxy-2-heptenal, and (E)-4-hydroxy-2-hexenal was achieved from the corresponding (2E,4E)-2,4-alkadienals by reduction-oxygenation with molecular oxygen and triethylsilane in the presence of cobalt(II) porphyrin as a catalyst followed by treatment with trimethylphosphite.

Microwave‐assisted Synthesis of N‐Hydroxyphthalimide Derivatives

Abstract N‐Hydroxyphthalimide derivatives are readily obtained in good yields by the reaction of phthalic anhydrides with hydroxylamine hydrochloride in the presence of pyridine under microwave irradiation.

Microwave-Assisted Beckmann Rearrangement of Aryl Ketoximes Catalyzed by In(OTf)3 in Ionic Liquid

Abstract Beckmann rearrangement of aryl ketoximes catalyzed by In(OTf)3 gave amides in ionic liquid under microwave irradiation. Aryl ketoximes were converted to corresponding amides in good yield within very short times (10–270 s). The catalyst and the ionic liquid were easily recovered and reused.

γ-selective hydroxylation of α,β,γ,δ-unsaturated carbonyl compounds and its application to syntheses of (±)-6-hydroxyshogaol and related furanoids

Abstract α,β,γ,δ-Unsaturated carbonyl compounds were converted regioselectively into γ-hydroxy-α,β-unsaturated carbonyl compounds by reduction-oxygenation with molecular oxygen and triethylsilane in the presence of cobalt(II) porphyrin as a catalyst followed by treatment with trimethyl phosphite. (±)-6-Hydroxyshogaol and related furanoids isolated from ginger were synthesized via this method.

Suppressing effect of cordycepin on the lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells

In this study, we focused on the anti-inflammatory effect of cordycepin, 3′-deoxyadenosine. Cordycepin potently suppressed nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 cells in an adenosine receptor-independent manner. In addition, inhibitors for adenosine kinase and nucleoside transporter abrogated the action of cordycepin. Thus, we considered that intracellular metabolism cordycepin is important for the anti-inflammatory effect of cordycepin.

Effectiveness of Lignin-Removal in Simultaneous Saccharification and Fermentation for Ethanol Production from Napiergrass, Rice Straw, Silvergrass, and Bamboo with Different Lignin-Contents

Second-generation biofuels from lignocellulosic materials have gained much attention since the lignocelluloses are not in competition with food sources and animal feed and will pro‐ vide a new sustainable energy sources alternative to petroleum-based fuels (Galbe and Zac‐ chi, 2007). Bioethanol production from herbaceous lignocellulose such as corn stover (Ryu and Karim, 2011), rice straw (Ko at al., 2009), sweet sorghum bagasse (Cardoba et al., 2010), switchgrass (Keshwani and Cheng, 2009), bamboo (Sathitsuksanoh at al., 2010), wheat straw (Talebnia et al., 2010), alfalfa stems (Gonzalez-Garcia at al., 2010), and silvergrass (Guo et al., 2008) has been extensively developed through a variety of processes combining the biologi‐ cal saccharification and fermentation steps with the pre-treatment methods. In almost all processes, the pretreatments to remove the lignin components and to promote an enzymatic digestibility of cellulosic components are carried out by the use of energy and cost which are frequently higher than those of bio-fuels gained (Alvira et al., 2010). If lignocelluloses with low lignin-content are selected, the operation to remove the lignin might be excluded from the bio-ethanol process.