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31.
Michio Masuda Tsuyoshi Abe Shinji Sato Teruaki Suzuki Minoru Suzuki 《Journal of phycology》1997,33(2):196-208
Many morphologically similar, but chemically distinct, populations have been found in the marine red alga Laurencia nipponica Yamada (Rhodomelaceae, Ceramiales) growing in Japan. Each chemical type is characterized by a specific end-product of halogenated secondaly metabolite synthesis: chamigrane-type sesquiterpenoids such as prepacifenol and halochamigrene epoxide and C15 bromoethers such as laurencin, laureatin, isoprelaurefucin, epilaurallene, and kumausallene. These seven types of secondary metabolite syntheses remained the same in the wild and under various culture conditions. Because bromoethers and terpenoids are probably synthesized by different metabolic pathways, it is virtually certain that different sets of enzymes participate in their synthesis. Prepacifenol- and laureatin-producing populations were selected as representatives of terpenoid and bromoether groups, respectively. F1 tetrasporophytes derived from crosses between reciprocal, female and male gametophytes of prepacifenol- and laureatin-producing strains bore both types of metabolites, suggesting that the genes Producing these enzyme systems are encoded by nuclear genomes. The F1 gametophytes resulting from the reciprocal crosses produced either prepacifenol or laureatin, and the four individuals derived from spore tetrads (a set of tetraspores derived from a single tetrasporangium) produced either prepacifenol or laureatin in a 1:1 ratio, indicating that genes participating in terpenoid synthsis and those participating in bromoether synthesis are on different loci of homologous chromosomes and are segregated at meiosis (tetrasporogenesis). One individual of this interpopulational F1 gamtophyte produced both parental types of metabolite, perhaps indicating the occurrence of a recombination type. Natural hybrid individuals, including such recombination-type gametophytes, were found in a sympatric locality at which these two chemical types occur. F1 tetrasporophytes derived from crosses between respective prepacifenol- and laureatin-producing strains and their F1 gametohytes produced only parental-type metabolite-producing plants. These results indicate that the diverse chemical types can be referred to as races (chemical races). 相似文献
32.
Quinolizidine alkaloids formed in the leaves of Lupinus albus L. are translocated via the phloem to the other plant organs, especially the maturing fruits. Compared with amino-acid transport in the phloem, the alkaloids contribute about 8% to the overall nitrogen being exported from the leaf. Since it is likely that the alkaloids are subsequently degraded in the target tissues a minor role of quinolizidine alkaloids might be nitrogen transport. A marked diurnal fluctuation of alkaloids was observed in the leaves, the phloem sap, the roots and the fruits with an increase during the day and an amplitude of several hundred percent thus providing evidence for a rapid turnover of endogenous alkaloids.Abbreviations QA
quinolizidine alkaloids
- GLC
gas-liquid chromatography 相似文献
33.
M. Zeches J. Lounkokobi B. Richard M. Plat L. Le Men-Olivier T. Sevenet J. Pusset 《Phytochemistry》1984,23(1):171-174
Fourteen alkaloids were isolated from the stem bark and aerial parts of Melodinus guillauminii. They were 11-hydroxytabersonine, venalstonine, venalstonidine, 14,15-seco-3-oxokopsinal, 3-oxovenalstonine, 11-methoxy-Δ14– vincamenine, 3-oxo-hydroxykopsinine, 11-methoxy-Δ14-vincanol, kopsinine, 15-α-hydroxykopsinine, 11-methoxy- tabersonine, pleiocarpamine, 19-β-hydroxyvenalstonine and guillauminiine. 相似文献
34.
From the mycelium of Penicillium cyclopium a biologically active fraction (P-factor) was isolated, which increases conidiation and the formation of the benzodiazepine alkaloids cyclopenin and cyclopenol. Its activity was determined by measuring the increase of alkaloid formation in strain SM 72. On a preparative scale P-factor preparations were obtained from fermenter-grown hyphae of mutant dev 63 by extraction with water at 120°. P-factor is strongly hydrophilic but it is not a protein. It was active if added during conidiospore germination and early growth phase, causing an acceleration of protein biosynthesis. The action on alkaloid biosynthesis and sporulation is indirect and resembles that of a developmental hormone. 相似文献
35.
Russell J. Molyneux James N. Roitman Mabry Benson Robert E. Lundin 《Phytochemistry》1982,21(2):439-443
The 13C NMR spectra of nine pyrrolizidine alkaloids of the macrocyclic diester type, seven of the corresponding N-oxides and of the parent base retronecine have been recorded and the signals assigned. The 13C NMR signals were found to be sensitive to structural variation in both the diester moiety and the heterocyclic ring system, providing useful information for structural elucidation, particularly when the 1H NMR spectra may be difficult to interpret. 相似文献
36.
James L. Catalfamo Michael W. Frohlich William B. Martin Helena Birecka 《Phytochemistry》1982,21(11):2677-2682
The qualitative and quantitative compositions of necines in plants of 20 Heliotropium species collected in Mexico and the U.S.A. and one species from Spain are reported. Trachelanthamidine, supinidine and retronecine were found in all species after hydrolysis of their alkaloids; lindelofidine was detected in most species, whereas heliotridine only in four. Trachelanthamidine, lindelofidine, and supinidine were dominant in four, two and one species, respectively; retronecine was dominant in 15 species, whereas heliotridine only in one. The dominant necine in H. ternatum was either retronecine or lindelofidine depending on the collection locality. Qualitative as well as quantitative differences depending on the collection locality were found in H. curassavicum. Plants from Oaxaca, Mexico, contained lindelofidine and a pyrrolizidine-diol as major necines, trachelanthamidine as minor, and traces of retronecine. Plants originating from two other localities contained trachelanthamidine (dominant), retronecine, and supinidine. The necine patterns found in the examined species differ significantly from those previously reported for 21 species mainly collected in Asia, the Middle East and Australia. 相似文献
37.
38.
Mohamed Saïd Hifnawy Jacqueline Vaquette Thierry Sévenet Jean-Louis Pousset André Cavé 《Phytochemistry》1977,16(7):1035-1039
Stems and leaves of Myrtopsis macrocarpa, M. myrtoidea, M. novae-caledoniae and M. sellingii yielded terpenes, sterols, coumarins, alkaloids (furoquinolines and quinolones) and amides. A new quinolone (8-methoxy flindersine) occurs in Myrtopsis macrocarpa, a new amide (N-benzoyltryptamine) in M. myrtoidea, two new coumarins (myrsellin and myrsellinol) and a new dihydrofuroquinoline (myrtopsine) in M. sellingii. Structures of the new compounds are proposed from chemical and spectroscopic evidence. 相似文献
39.
A new alkaloid, majvinine, was isolated from aerial parts of Vinca major. Its structure was determined by chemical and spectroscopic investigations 相似文献
40.
Hubert G. Theuns Jan E.G. van Dam Jan M. Luteijn Cornelis A. Salemink 《Phytochemistry》1977,16(6):753-755
Three new alkaloids have been identified from Papaver bracteatum, 14-β-hydroxycodeinone, 14-β-hydroxycodeine and N-methylcorydaldine. The presence of alpinigenine was also confirmed. 相似文献