Numerous investigations have been carried out on the spectral distribution of the light of different species of fireflies. Here we record the emission spectrum of the Indian species of the firefly Luciola praeusta Kiesenwetter 1874 (Coleoptera : Lampyridae : Luciolinae) on a color film. Green and red color-sectors, with an intense yellow one in between, appear in this spectrum. Intensity profile of this spectrum reveals a hitherto undetected strong narrow yellow line, which lies within the full-width-at-half maximum (FWHM) of the intensity profile. The spectrum recorded in a high-resolution spectrometer confirms the presence of this sharp intense line. This finding lends support to an earlier drawn analogy between the in vivo emission of the firefly and laser light. 相似文献
Retinoyl beta-glucuronide and retinyl beta-glucuronide, which are naturally occurring water-soluble metabolites of vitamin A, induce the granulocytic differentiation of HL-60 cells in vitro, as evidenced by an increased reduction of nitroblue tetrazolium. The relative effectiveness of various retinoids in differentiation is retinoic acid greater than retinoyl beta-glucuronide greater than retinyl beta-glucuronide. Under the selected assay conditions, retinol, hydroxyphenyl-retinamide, retinamide, and N-retinoyl-phenylalanine are essentially inactive in differentiation. At concentrations of retinoids from 10(-9) to 10(-5) M, cell viability was best with the retinoid beta-glucuronides and retinamide, less with retinoic acid and retinol, and poorest with the N-retinoyl aromatic amines. Cellular growth was depressed only slightly by retinyl beta-glucuronide and retinamide, but to a greater degree by the other derivatives. Retinoyl beta-glucuronide was hydrolyzed in part to retinoic acid, whereas retinyl beta-glucuronide was cleaved to retinol, if at all, at a very slow rate. Under the selected assay conditions, retinoic acid and the retinoid beta-glucuronides primarily induce the differentiation of HL-60 cells, whereas the N-retinoyl aromatic amines show cytotoxicity. 相似文献
All-trans-[11-3H]retinoyl beta-glucuronide (RAG) was synthesized in a single step from all-trans-[11-3H]retinoyl fluoride, with a 24% yield. After its intraperitoneal injection into rats, RAG was detected in the blood, liver, intestine and kidney during the following 24 h period. Although the concentration of radiolabelled metabolites decreased with time, RAG predominated at nearly all times in nearly all tissues. Small amounts of retinoic acid (RA) were also universally present, together with unidentified polar metabolites and small amounts of non-polar esters of RA. The major excretion products of RAG in faeces and urine were RA and polar metabolites. Thus RAG, although converted in part to RA in vivo, persists as a major component in blood and tissues for at least 24 h. These observations support the concept that the retinoid beta-glucuronides might serve a physiologically significant role in the function of vitamin A. 相似文献
Retinoyl fluoride (2) prepared from retinoic acid (1) by reaction with diethylaminosulfurtrifluoride is a stable crystalline compound not easily hydrolyzed by water. By reacting retinoyl fluoride with water-soluble amines in the presence of sodium bicarbonate, retinamide (4), N-retinoyl glycine (6), N-retinoyl DL-phenylalanine (7), alpha-N-retinoyl-L-lysine (11), N-retinoyl 4-aminophenol (4-hydroxyphenylretinamide) (8), and N-retinoyl-2-amino-2-deoxy-D-glucose (2-deoxy-D-glucose-2-retinamide) (9) have been prepared in good yields and characterized by UV absorption, 1H NMR, IR spectra, mass spectrometry, and elemental analysis. 相似文献
1. ;Naturally occurring anhydrovitamin A(2)' obtained from the liver oil of freshwater fish Bagarius bagarius yielded, after six-stage chromatography, a pure product showing characteristic bands at 350, 368 (E(1%) (1cm.) 1006) and 390mmu in ethanol, and producing a green colour with antimony trichloride (E(1%) (1cm.) 1884 at 693mmu). 2. On distribution of the material between light petroleum and 95% methanol, 70% of it is found in methanol, which points to its hydroxylic character. 3. It gives an acetyl derivative, from which the original hydroxy compound can be regenerated on hydrolysis. 4. The infrared spectrum shows, besides other bands, one at 3460cm.(-1) attributable to a hydroxy group. 5. On passing a light-petroleum solution of naturally occurring anhydrovitamin A(2) through manganese dioxide a 6% conversion into retinene(2) is observed. 6. A 3-hydroxyanhydroretinol structure is proposed for naturally occurring anhydrovitamin A(2) and a mechanism of its transformation into retinene(2) on this basis is suggested. 相似文献
1. Anthers of Delonix regia flowers are a rich source of zeaxanthin. 2. Oxidation of zeaxanthin with hydrogen peroxide in the presence of osmium tetroxide results in the formation of 3-hydroxyretinene as one of the products. 3. 3-Hydroxyretinene gives 3-acetoxyretinene with acetic anhydride, and an oxime with hydroxylamine hydrochloride. 4. Reduction of 3-hydroxyretinene with sodium borohydride yields 3-hydroxyvitamin A. 5. Treatment of 3-hydroxyvitamin A with dry ethanolic hydrogen chloride results in the formation of 3-ethoxyanhydrovitamin A (anhydrovitamin A2) and a compound that resembles naturally occurring anhydrovitamin A2. 相似文献
A 405 nm diode laser is used to excite fluorescence of juices of raw and ripe lemons. Emission bands appear approximately at 520 nm and 670 nm. Fluorescence intensity ratio F520/F670 is determined for the two stages. Variation in the fluorescence intensity ratio is observed during the process of ripening or growth of the fruit. Time-resolved spectra at this excitation wavelength reveal two decay times at both the stages at the emission wavelength of 520 nm, and two decay times at the raw stage and one decay time at the ripe stage at 670 nm. 相似文献
The central nervous system (CNS) is the most injury-prone part of the mammalian body. Any acute or chronic, central or peripheral neurological disorder is related to abnormal biochemical and electrical signals in the brain cells. As a result, ion channels and receptors that are abundant in the nervous system and control the electrical and biochemical environment of the CNS play a vital role in neurological disease. The N-methyl-d-aspartate receptor, 2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl) propanoic acid receptor, kainate receptor, acetylcholine receptor, serotonin receptor, α2-adrenoreceptor, and acid-sensing ion channels are among the major channels and receptors known to be key components of pathophysiological events in the CNS. The primary amine agmatine, a neuromodulator synthesized in the brain by decarboxylation of l-arginine, can regulate ion channel cascades and receptors that are related to the major CNS disorders. In our previous studies, we established that agmatine was related to the regulation of cell differentiation, nitric oxide synthesis, and murine brain endothelial cell migration, relief of chronic pain, cerebral edema, and apoptotic cell death in experimental CNS disorders. In this review, we will focus on the pathophysiological aspects of the neurological disorders regulated by these ion channels and receptors, and their interaction with agmatine in CNS injury.