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14. Oryzamutaic acids H–J, new alkaloids from an Oryza sativa mutant with yellow endosperm

Author

Nakano, Hiroshi, Kosemura, Seiji, Yoshida, Mitsuru, Iwaura, Rika, Suzuki, Toshisada, Kaji, Ryota, and Sakai, Makoto

Subjects
*ALKALOIDS, *RICE, *ENDOSPERM, *NITROGEN, *HETEROCYCLIC compounds, *MOLECULAR structure, *STEREOCHEMISTRY, *SPECTRUM analysis
Abstract

Abstract: Three new nitrogen-containing heterocyclic alkaloids, oryzamutaic acids H–J (1–3), were isolated from the endosperm (polished rice) of an Oryza sativa mutant. The structures and relative stereochemistries of 1–3 were elucidated on the basis of spectroscopic analyses. The presence of three carbons, each bound to a carboxyl group and a nitrogen atom in the structure of 1, suggests that oryzamutaic acids H–J (1–3) are generated from three molecules of a single amino acid. [ABSTRACT FROM AUTHOR]

Published
2010
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15. Oryzamutaic acids B–G, new alkaloids from an Oryza sativa mutant with yellow endosperm

Author

Nakano, Hiroshi, Kosemura, Seiji, Yoshida, Mitsuru, Suzuki, Toshisada, Iwaura, Rika, Kaji, Ryota, Sakai, Makoto, and Hirose, Katsutoshi

Subjects
*ALKALOIDS, *PLANT mutation, *ENDOSPERM, *CHEMICAL structure, *NITROGEN, *HETEROCYCLIC compounds, *STEREOCHEMISTRY
Abstract

Abstract: Oryzamutaic acids B–G (1–6), structurally unique nitrogen-containing heterocyclic alkaloids, were isolated from the endosperm (polished rice) of an Oryza sativa mutant. The structures and relative stereochemistries of 1–6 were elucidated on the basis of spectroscopic and single-crystal X-ray diffraction analyses. [Copyright &y& Elsevier]

Published
2010
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16. Allelopathy of pinecone in Japanese red pine tree (Pinus densiflora Sieb. et Zucc.).

Author

NODE, MARI, TOMITA-YOKOTANI, KAORI, SUZUKI, TOSHISADA, KOSEMURA, SEIJI, HIRATA, HIROAKI, HIRATA, KIMINORI, NAWAMAKI, TSUTOMU, YAMAMURA, SHOSUKE, and HASEGAWA, KOJI

Subjects
PINE cones, JAPANESE red pine
Abstract

There are fewer weeds in the ground covered with pinecones of Japanese red pine trees (Pinus densiflora Sieb. et Zucc.) than in the ground without pinecones. When six species of seeds were cultured with Japanese red pinecones on agar, the growth of cress, lettuce and cat's eye were inhibited. Pinecones had a plant species-selective influence on their growth. Exudates of the pinecones showed high biological activity and also plant species-selective activity. Some species-selective allelopathic substances may be released from the pinecones. One of the inhibiting allelopathic substances was isolated from the exudates of the pinecones using a bioassay of cat's eye. The substance was identified as phenylacetic acid from an ESI-MS and 1 H NMR spectra. It inhibited shoot and radicle elongation of cat's eye at concentrations of 30–100 p.p.m. The substance was also isolated from an agar medium after removal of the pinecones. These results suggest that pinecones may inhibit some weeds that grow around pine trees. There are many reports of the allelopathic effect of leaves, bark and roots of many plants, however, this is the first report that reveals the cone also affects the allelopathy phenomenon in Japanese red pine trees. [ABSTRACT FROM AUTHOR]

Published
2003
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17. Structure and absolute configuration of citreohybridones isolated from Penicillium species

Author

Kosemura, Seiji

Subjects
*TERPENES, *PENICILLIUM, *MOLECULAR structure
Abstract

Four new meroterpenoids have been isolated from the mycelium of the hybrid strain KO 0031 derived from Penicillium citreo-viride B. IFO 6200 and 4692. Their stereostructures have been elucidated on the basis of their spectral data and some chemical evidence, and their absolute configurations have also been elucidated by the modified Mosher''s methods. [Copyright &y& Elsevier]

Published
2002
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21. Oryzamutaic acid A, a novel yellow pigment from an Oryza sativa mutant with yellow endosperm

Author

Nakano, Hiroshi, Kosemura, Seiji, Suzuki, Toshisada, Hirose, Katsutoshi, Kaji, Ryota, and Sakai, Makoto

Subjects
*AMINO acids, *PLANT extracts, *ENDOSPERM, *RICE, *SPECTRUM analysis, *X-ray diffraction
Abstract

Abstract: Oryzamutaic acid A, a novel yellow pigment, was isolated from the endosperm of an Oryza sativa mutant. The structure and absolute configuration of oryzamutaic acid A were elucidated on the basis of spectroscopic analysis, single-crystal X-ray diffraction analysis, and biogenetic reason. Oryzamutaic acid A might be biogenetically derived from four l-amino acids because it contains three amino acid groups and one amine group. [Copyright &y& Elsevier]

Published
2009
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