scholarly journals Identification of Chalcones and their Contribution to Yellow Coloration in Dahlia (Dahlia variabilis) Ray Florets

Author(s):  
Sho Ohno ◽  
Mizuki Yokota ◽  
Haruka Yamada ◽  
Fumi Tatsuzawa ◽  
Motoaki Doi
2012 ◽  
Vol 19 (2) ◽  
pp. 195-197 ◽  
Author(s):  
Gianfranco Carotenuto ◽  
Mariano Palomba ◽  
Luigi Nicolais

AbstractLightfast color filters (intensively and brightly colored) can be easily produced by dying optical plastics with the surface plasmon resonance (SPR) of metal nanoparticles such as silver and gold. Here, color filters based on silver nanoparticles embedded in amorphous polystyrene have been prepared by dissolving and thermally decomposing (1,5-cyclooctadiene)(hexafluoro-acetylacetonate)silver(I) in amorphous polystyrene. The metal precursor quickly decomposes (10 s, at 180°C), leading to silver atoms that clusterize and produce a non-aggregated dispersion of silver particles in the polymer matrix. The intensity of the yellow coloration due to the SPR of nanoscopic silver can be widely tuned simply by varying the cluster numerical density in the polymer matrix that depends on the silver precursor concentration. The obtained nanocomposite films have been characterized by X-ray power diffraction, transmission electron microscopy, and UV-Vis spectroscopy.


2017 ◽  
Vol 17 (5) ◽  
pp. 3424-3429
Author(s):  
JiYeon Yun ◽  
Ri Yu ◽  
Sungjin Park ◽  
Jae-Hwan Pee ◽  
YooJin Kim
Keyword(s):  

2009 ◽  
Vol 95 (26) ◽  
pp. 262104 ◽  
Author(s):  
A. Sedhain ◽  
L. Du ◽  
J. H. Edgar ◽  
J. Y. Lin ◽  
H. X. Jiang
Keyword(s):  

1894 ◽  
Vol 55 (331-335) ◽  
pp. 394-407 ◽  

The uncertainty which still surrounds the origin of a phenomenon so familiar as the yellow coloration of the urine bears eloquent testimony to the difficulties which beset the investigation, by ordinary chemical methods, of such substances as the urinary pigments, and to the importance of the part which the spectroscope has played in the acquisition of such knowledge of them as we possess. Indeed, our acquaintance with the individual pigments is proportional to the distinctive character of their absorption spectra, rather than to the time which has elapsed since they first attracted attention; and in not a few modern works doubt is thrown upon the very existence of a distinct yellow pigment, having negative spectroscopic properties, but to which normal urine owes its characteristic tint, the chief part in the coloration of the excretion being assigned to urobilin.


2019 ◽  
Vol 52 (1) ◽  
pp. 74-78
Author(s):  
S. Buhăianu ◽  
Doina Carmen Jităreanu

Abstract Chlorophylls from plants are photosynthetic pigments. Their quantity offers valuable informations about photosynthetic activity, growing and developing of plants. Photosynthetic pigments decrease quantitatively during senescence process or in stress conditions. The present study has been realized in laboratory conditions with material harvested from spontaneous flora. The purpose of this research was the investigation of variations of chlorophyll content from samples of biological material collected from Nepeta pannonica L. and Abies alba Mill. plants, from Câmpulung Moldovenesc and Cacica areas, Suceava county, Romania. The targeted phenophases were growth and flowering. There were realized acetonic extracts from samples for spectrophotometric determinations. Obtained data were processed to estabilish chlorophyll a and b content. There were observed that at Abies alba species, from both locations, the chlorophyll a content grew during flowering phenophase, while the chlorophyll b content had little variations. At Nepeta pannonica species, the chlorophyll a and b content decreased visibly during the flowering, due to stress. Leaves of plants from this species presented a intense green color in the growing phenophase, while during flowering phenophase they had a purple or yellow coloration. Obtained results revealed a different dynamics of chlorophyll content at studied species.


2021 ◽  
Vol 106 ◽  
pp. 340-371
Author(s):  
Joel Calvo

The Neotropical genus Pentacalia Cass. (Compositae, Senecioneae) is distributed from southern Mexico to northwestern Argentina, plus two disjunct species that thrive in Brazil. Most species diversity occurs in the montane forests of Colombia, Ecuador, and Peru. It comprises scandent woody plants characterized by displaying alternate leaves (opposite in three species), involucres with supplementary bracts, usually yellow ray florets (when present), sagittate to caudate anther bases, and truncate to obtuse style branches with a crown of sweeping trichomes (sometimes with a tuft of longer trichomes, but not strictly penicillate). The Bolivian species were revised for the first time by Cabrera (1985), who treated the group under Senecio L. sect. Streptothamni Greenm. Because of the subsequent addition of new species and the need of taxonomic arrangements, an updated synopsis of the genus recognizing 18 species is presented. The names P. brittoniana (Hieron.) Cuatrec. and P. miguelii (Cuatrec.) Cuatrec. are synonymized with P. psidiifolia (Rusby) Cuatrec., as well as P. inquisiviensis H. Rob. & Cuatrec. with P. cardenasii (Cuatrec.) Cuatrec. and P. sailapatensis (Cuatrec.) Cuatrec. with P. urubambensis (Cabrera) Cuatrec. Seven names are lectotypified and an epitype is designated for the name P. zongoensis (Cabrera) J. Calvo. The new species P. viburnifolia J. Calvo & A. Fuentes is described. Revised nomenclature, succinct descriptions, taxonomic discussions, lists of specimens examined, and distribution maps are provided for all accepted species, in addition to an identification key. Pictures of living plants are also presented for eight species.


Rodriguésia ◽  
2021 ◽  
Vol 72 ◽  
Author(s):  
Aristônio Magalhães Teles ◽  
Geovana Vieira da Fonseca ◽  
Lidyanne Yuriko Saleme Aona

Abstract The genus Pentacalia belongs to the tribe Senecioneae. It is represented by approximately 160 species predominantly distributed in the Andes. Species of Pentacalia are characterized by having a scandent habit, usually alternate leaves, axillary or terminal capitulescence, homogamous or heterogamous capitula, commonly yellow ray-florets, yellowish, creamy, or whitish disc-florets, sagittate to caudate anther-bases, and cypselae with five to ten ribs. The aim of the present study was to perform a taxonomic treatment of Pentacalia in Brazil, where it is represented by two species, P. desiderabilis and P. tropicalis, from the Atlantic Forest Domain. Detailed descriptions, taxonomic discussions, geographical distributions, an identification key, illustrations and a new record of P. tropicalis for the Northeast Region are presented. Moreover, three names (Senecio desiderabilis, S. ellipticus, and S. tropicalis) are lectotypified.


2019 ◽  
Vol 88 (4) ◽  
pp. 521-534 ◽  
Author(s):  
Takashi Onozaki ◽  
Mirai Azuma

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