Jiro Motoyoshiya

A new substance (Yoshixol) with an interesting antibiotic mechanism from wood oil of Japanese traditional tree (Kiso-Hinoki), Chamaecyparis obtusa

1. A neutral wood oil was extracted from Chamaecyparis obtusa (Kiso-Hinoki), which has been trusted nationally and preserved historically in the central part of Japan (Kiso, Nagano). 2. Hinokitiol, or thujaplicin (C10H12O2), which has been believed to exist in Cupressaceae, was not found in this neutral wood oil. Some differences between the extracting processes of the natural products are discussed. 3. A new chemical substance (Yoshixol, 4,4-dimethyl-6-methylene-2-cyclohexen-1-one) was simulated by several criteria (details in the text) as a major candidate of the neutral wood oil from Chamaecyparis obtusa. Thus, Yoshixol was newly synthesized. 4. The antibiotic effects of hinokitiol, the neutral wood oil and Yoshixol on methicillin-resistant Staphylococcus aureus (MRSA) were examined bacteriologically and morphologically. 5. All of the aforementioned three test materials showed complete antibiotic effects on MRSA by the bacteriological examination. However, the morphological findings showed entirely different aspects of cell death. 6. Hinokitiol caused an aggregative, degenerative and/or necrotic aspect, but the neutral wood oil and Yoshixol produced characteristic aspects: separation of contacted cells, blebbing, bugging-like eruption, formation of granules and an extensive reduction of individual cell size of MRSA. 7. Yoshixol was able to enhance those antibiotic effects on MRSA distinctly more than the neutral wood oil. 8. Yoshixol also showed a strong antibiotic effect on Escherichia coli, Mycobacterium chelonei, Pseudomonas aureginosa and Candida albicans. Morphological observations of those bacilli after Yoshixol revealed characteristic aspects of separation of contacted cells, bugging-like swelling, granulation, ballooning and reduction of cell size. 9. A possible mechanism of Yoshixol is discussed in regard to a molecular orbital theory on the basis of its electron orbits and to a thermodynamic interaction with the prokaryotic cell membrane. On the basis of the molecular properties of Yoshixol, future biological interests and possible biological effects of Yoshixol are suggested.

Facile and reversible synthesis of an acidic water-soluble poly(amidoamine) fullerodendrimer

Water-soluble fullerodendrimer was obtained by the use of a Diels–Alder reaction of C60 with a newly designed anthryl dendron under an extremely mild condition in 70% yield, which is more than five times as high as the yield described in our previous report.

Naphthoquinones from juglandaceae

Abstract The oligomeric juglones isolated from the barks of Juglandaceae plants, Pterocarya and Juglans , were shown to be 3,3′-bijuglone (8,8′-dihydroxy[2,2′-binaphthalene]-1,1′,4,4′-tetrone and unsymmetrical cyclotrijuglone ( 1,7,16-trihydroxy-5,6,11,12,17,18-trinaphthalenehexone).

Highly Cis-Selective Horner-Wadsworth-Emmons (HWE) Reaction of Methyl Bis(2,4-Difluorophenyl) Phosphonoacetate

Abstract Of the previously reported Horner-Wadsworth-Emmons (HWE) reaction, the olefination of methyl bis(2,4-difluorophenyl)phosphonoacetate (la) with various aldehydes gave unsaturated esters in the highest cis-selectivity.

The Horner–Wadsworth–Emmons reaction of mixed phosphonoacetates and aromatic aldehydes: geometrical selectivity and computational investigation

Abstract The substituent effect on the geometrical selectivity in the Horner–Wadsworth–Emmons (HWE) reaction was studied employing several mixed phosphonoacetates. Their reactions with aromatic aldehydes showed a gradual change in Z -selectivity according to the electron-withdrawing ability of the phosphonate substituents, and there was a good correlation between the observed selectivities and 31 P chemical shifts of the phosphonoacetates. Some variables such as the metal cation and crown ether also affected the selectivity. A computational study using ab initio and semi-empirical calculations suggests that the electron-withdrawing substituents stabilize the intermediates as well as the transition states, which reduces the reversibility to increase Z -products. This is in agreement with the experimentally observed selectivity.

SmI2-promoted Reformatsky-type reaction and acylation of alkyl 1-chlorocyclopropanecarboxylates.

In the presence of HMPA in THF, highly stereoselective SmI(2)-promoted substitutions of alkyl 1-chlorocyclopropanecarboxylates 1 using various ketones, aldehydes (Reformatsky-type reaction), and acyl chlorides (acylation) proceeded to give trans-adducts (2 or 5) in good to high yield with excellent trans-stereoselectivity (trans-add/cis-add = > 99/1). The Reformatsky-type reaction of 1 with aldehydes and unsymmetrical ketones proceeded with moderate diastereoselectivity (re-face-adduct/si-face-adduct = 60/40-75/25).

Thermal Reactions of N -Phenylmaleimide and Mono- or Di-functional Allylphenols

Thermal reactions of N-phenylmaleimide (PMI) and o-allylphenol (AP) or diallylbisphenol-A (DABA) were investigated using 13C NMR and GPC in order to obtain information on the curing of bismaleimidodiphenylmethane (BMI) with DABA, widely used as thermosetting bismaleimide resins. In the thermal reactions of PMI and AP, 1:1 and 3:1 adducts were generated through ene-reaction and sequential Diels-Alder reactions accompanying the polymer of PMI and AP. The products from PMI and DABA were the ene-adduct and polymer but the Diels-Alder adduct could not be detected, in contrast to PMI/AP system. This difference in reactivity for PMI-AP and PMI-DABA may be due to steric repulsion of DABA and is discussed briefly by AM1 molecular orbital calculations.

Effect of boron trifluoride-diethyl ether (BF3.OEt2= in the Diels-Alder reaction of quinoline- and isoquinoline-5,8-dione with unsymmetrical aliphatic dienes : theoretical study on the orientation of cycloadditions

The Diels–Alder reaction of quinoline- and isoquinoline-5,8-dione with piperylene or isoprene gave regioisomers of the substituted azaanthraquinones, while the Lewis acid catalyst boron trifluoride–diethyl ether showed a drastic effect on regioselectivity in the reactions with piperylene. The Frontier Molecular Orbital (FMO) theory (calculated by CNDO/2 method) was applied to explain the orientation of the catalysed regioselective cycloadditions, by considering secondary orbital interactions.

Synthesis and Characterization of a Poly(Benzyl Ether) Dendron Sulfenyl Iodide

Abstract A poly(benzyl ether) dendron with a sulfenyl iodide group at the focal point was synthesized and well characterized. Although the molecule showed high stability to chemical reactions, the corresponding den-drimer disulfide was obtained upon photoirradiation quantitatively.

A STUDY ON THE Z-SELECTIVE HORNER-WADSWORTH-EMMONS (HWE) REACTION OF METHYL DIARYLPHOSPHONOACETATES

Abstract Experimental and theoretical studies were conducted to explore the Z-selectivities in the Homer-Wadsworth-Emmons (HWE) reaction employing several methyl diarylphosphonoacetates (3, 4, 5 and 6) and aldehydes. The Z-selectivity depended upon the reaction conditions such as the bases, reaction temperature, and the aromatic suhstituents on the phosphorus atoms but the almost phosphonoacetates used in the present study showed Z-selectivity in the reactions with both aromatic and aliphatic aldehydes. While the phosphonoacetate (3) with bis(2,4-difluorophenyl)phosphono group showed the highest Z-selectivity in all reaction conditions employed, decrease of the selectivity was observed in the case of some phosphonoacetates with diarylphosphono groups. These experimental results and the theoretical studies calculated by AM1 or 3-21G* ab initio methods suggested that the steric effect in the transition states of the addition steps was important rather than the electronic effect. A different aspect of the re...