Comparison of action spectra for acute cutaneous responses to ultraviolet radiation: man and albino hairless mouse

Abstract The hairless mouse has been used as an experimental model for photocarcinogenesis for about 20 years. Although the carcinogenesis action spectra for mice and man are not known, acute responses to ultraviolet radiation (UVR) in the biologically active UVB and UVC region (wavelengths below 320 nm) can be compared. Vascular response (predominantly edema) action spectra for monochromatic radiation in the Skh:HR-l (albino hairless) male mouse were determined. These action spectra were found to be very similar to the human erythema action spectrum that had been developed using the same monochromator. The accuracy of this experimentally derived action spectrum was tested with a series of polychromatic source spectra. The mice were exposed to radiation from a long arc Xe lamp filtered by varying thicknesses of Schott WG320 filters, which yielded a wide range of biologically effective spectra. Spectral irradiance measurements, when weighted with the mouse edema and human erythema action spectra and multiplied by the irradiation time required to elicit a threshold response (edema), yielded a constant weighted dose regardless of irradiation spectral quality. The integrated effective dose was approximately 200 J/m² of 297 nm equivalent energy, agreeing with requirements for the monochromatic 297 nm dose in the mice as well as for minimal human erythema. These data suggest a commonality in the UVR chromophores of mice and men as they relate to the acute responses described, and a direct additivity of effectiveness from the UVR components in a polychromatic beam, at least over the portion of the UVR spectrum tested (λ > 295 nm).     

Seasonal variation in total phenolic and flavonoid contents and DPPH scavenging activity of Bellis perennis L. flowers

Variations in total phenolic and flavonoid contents as well as antioxidant activity of Bellis perennis (common daisy) flowers were investigated. The flowers were collected monthly (from March to October, i.e., during the usual flowering season of the plant) at three localities in three different years. Total flavonoids were determined spectrophotometrically by two methods: by formation of a complex with aluminium chloride after acidic hydrolysis of flower extracts (method 1) and by reaction with boric and oxalic acids in extracts without their modification (method 2). Total phenolics were determined spectrophotometrically using the Folin-Ciocalteu reagent. The antioxidant activity was determined spectrophotometrically by a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. The contents of flavonoids varied from 0.31 to 0.44 mg quercetin equivalent/100 mg dry weight (method 1) and from 1.37 to 2.20 mg pigenin-7-glucoside equivalent/100 mg dry weight (method 2). Total phenolics ranged from 2.81 to 3.57 mg gallic acid equivalent/100 mg dry weight. The antioxidant activity expressed as IC(50) values varied from 66.03 to 89.27 μg/mL; it is about 50, 30, 20, and 10 times lower as compared with quercetin, ascorbic acid, Trolox?, and butylhydroxytoluene, respectively, and about five times higher in comparison with apigenin-7-glucoside. There is a significant correlation between antioxidant activity and total phenolics. No correlation between total flavonoid contents and antioxidant activity was observed. Contents of phenolics and flavonoids as well as antioxidant activity of daisy flowers vary to a relatively small extent during the year and are not dependant on the time of collection. Thus, the flowers possess comparable quality as to these characteristics over the whole flowering season of Bellis perennis. Effects of environmental factors on the amounts of secondary metabolites in plants are also discussed.     

Similarity in dose responses, action spectra and red light responses between phototropism and photoinhibition of growth.

Abstract— First positive phototropism and photoinhibition of growth of oat colcoptiles share similar dose response curves and action spectra. Both responses increase with increasing dosage of blue light (440 nm) up to 10¹³ photons cm^-2, then both decrease with increasing dosage. Action spectra for both responses have peaks at 360, 440, and 470 nm. When red light (660 nm) was given beforehand, the sensitivity of each response to blue light was lessened. These data indicate a close correlation between phototropism and photoinhibition of growth. Both phenomena can be explained as a result of photoinhibition of basipetal transport of auxin.     

Synthesis of a tetrasaccharide related to the triterpenoid saponin Bellisoside isolated from Bellis perennis (compositae)

A concise synthesis of a tetrasaccharide related to the triterpenoid saponins Bellisoside has been accomplished from commercially available monosaccharides through rational protecting group manipulations and stereoselective glycosylations. For the glycosylation reactions, H₂SO₄–silica has been successfully used as an alternative to conventional Lewis acids such as TfOH or TMSOTf. The target tetrasaccharide has been synthesized in the form of its p-methoxyphenyl glycoside which leaves scope for further glyco-conjugate formation through the selective deprotection of p-methoxyphenyl glycoside followed by trichloroacetimidate chemistry.     

Computation of ultraviolet and visible spectra for cobalt acetylacetonate

A computation is made for the Co(acac)₃ molecule by the semiempirical method of Mulliken, Helmholz, and Wolfsberg. The results indicate a high degree of covalence in the metal—ligand bond. Analysis of the obtained system of energy levels and oscillator forces for the possible transitions makes it possible to interpret the 1100 nm and 800 nm bands as transitions from the -orbitals of the carbon atoms in the ortho position to the metal to the d orbitals of the metal; the bands in the 400- to 610-nm region are interpreted as d()-d transitions, which cannot be regarded as pure d-d transitions. The bands in the region below 400 nm are attributed to - transitions. The calculation also shows that in complexes with covalent metal-ligand bonds the levels, to which the main contribution is made by the atomic orbitals of the metal and the directly coordinated atoms, are mixed.     

Structure and ultraviolet absorption spectra of indazolones

The UV spectra of indazolone and its derivatives are investigated, and hypotheses regarding their structure advanced. It is shown that the UV spectra of 1- and 2- acylindazolones have different characters, which can be utilized to identify those particular isomers.     

Experimental and theoretical ultraviolet spectra of haloindoles

The UV spectra of indole and the 4-, 5-, 6-, and 7-haloindoles (X=F, Cl, Br) have been recorded in methanol and calculated using time-dependent density functional theory. The lowest-energy UV absorption of each of the indoles is due to the HOMO-LUMO transition. This transition shifts to the red for the haloindoles relative to indole mainly as a result of the destabilization of the haloindole HOMOs.     

Phytochrome-mediated inhibition of coleoptile growth in rice: age-dependency and action spectra

Phytochrome has been shown to be the major photoreceptor involved in the photo-inhibition of coleoptile growth in Japonica-type rice (Oryza sativa L.). We have characterized this typical photomorphogenetic response of rice using mutants deficient in phytochrome A (phyA) and phytochrome B (phyB) and with respect to age-dependency and action spectra. Seedlings were irradiated with a pulse of light 40 h or 80 h after germination (i.e. at an early or late developmental stage) and the final coleoptile length of these seedlings was determined. A saturating pulse of red light (R) had a stronger effect when it was given in the late stage than in the early stage. It was found that the photoinhibition is mediated by both the phyA and the phyB in the late stage but predominantly by phyB in the early stage. Consistent with many other reported responses, the photo-inhibition in the phyA mutant, which was observed in the early and late developmental stages and is thought to be mediated mainly by phyB, occurred in the low-fluence range (10(1)-10(3) micromol m(-2)) of R and was far-red-light (FR)-reversible; the photo-inhibition in the phyB mutant, which was observed in the late developmental stage and is thought to be mediated mainly by phyA, occurred in the very-low-fluence range (10(-2)-10(0) micromol m(-2)) and was FR-irreversible. The action spectra (350-800 nm at 50 nm intervals) obtained at the two developmental stages using phyA and phyB mutants indicated that both the phyB-mediated low-fluence response and the phyA-mediated very-low-fluence response have a major peak at 650 nm and a minor peak at 400 nm.     

Theoretical investigation of carotenoid ultraviolet spectra

We have determined the π band‐gaps of the main carotenoids present in poly(methyl)methacrylate/buriti blends, namely, trans‐β‐carotene, 13‐cis‐β‐carotene, 9‐cis‐β‐carotene, phytofluene, and zeaxanthin. Semiempirical, model Hamiltonian, and density functional calculations were carried out to study these structures. The geometries were fully optimized using AM1, PM3, and B3LYP/6‐31G(d,p) methods. The TD‐DFT and ZINDO/S methods were applied for the calculation of the electronic absorption spectra of the optimized B3LYP geometries. The calculated spectra using the polarizable continuum model for the solvent effects were compared with the available experimental. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009     

The Raman and near ultraviolet spectra of thioanisole

The liquid Raman and vapour phase u.v. absorption spectra of thioanisole have been recorded and vibrational analyses performed. The vibrational structure accompanying the π* ← π electronic transition is similar to that in related monosubstituted benzenes and shows activity in the in-plane ring vibrations 1, 7a, 6a, 6b, 12 and 18b.     

Gas phase ultraviolet photoelectron spectra of hydroxyanthraquinones

The gas phase u.v. photoelectron spectra of anthraquinone, 1,4-OH-1,8-OH-2,6-OH-1-NH₂-and 1-NH₂-4-OH-anthraquinones have been measured using HeI radiation. Semiempirical HAM/3 calculations have been employed to help in the band assignment. The lowest ionization potential of all the studied compounds is of π-type, except of anthraquinone where the n-O(CO) ionization is the lowest one. The results show that the intramolecular OH ⋯ O bonding stabilizes the n-orbital by ca 0.4 eV, and that the IP_n+−IP_n− energy difference should not exceed 0.5 eV, very close to that found in para-benzoquinone. No hydrogen bonding effects of the NH₂ group are apparent.     

Deconvolution of multicomponent ultraviolet/visible spectra

A reliable method based on non-negative least squares is suggested for the deconvolution of spectra of chemical and biochemical mixtures into their individual components. The efficiency of the method is demonstrated by use of artificial inorganic salt mixtures of defined composition as well as of real carotenoid samples of considerable complexity, the results for which are compared with those of conventional chromatography. The problem of error propagation is discussed and compared to the sensitivity of standard least-squares and n-wavelengths algorithms.     

Vacuum ultraviolet absorption spectra of simple amides

Vacuum ultraviolet absorption spectra of six simple amides were measured. It was found that the positions of the firstπ→π ^* transition bands shift appreciably by the substitutions of methyl groups for hydrogen atoms of the NH₂ and\(\begin{gathered} | \hfill \\ H - C = O \hfill \\ \end{gathered} \) groups. A general tendency is that the substitution in the NH₂ group shifts the band toward longer wavelengths, in the\(\begin{gathered} | \hfill \\ H - C = O \hfill \\ \end{gathered} \) group however towards shorter wavelengths. This was explained satisfactorily by considering the nature of the band (intramolecular charge-transfer band) and the hyperconjugation effect of the methyl group.     

Medicinal Flowers. XXXII. Structures of oleanane-type triterpene saponins, perennisosides VIII, IX, X, XI, and XII, from the flowers of Bellis perennis

Five new triterpene saponins perennisosides VIII (1), IX (2), X (3), XI (4), and XII (5) were isolated from the MeOH-eluated fraction of the methanolic extract from the flowers of Bellis perennis. The MeOH-eluted fraction of the methanolic extract from the flowers of B. perennis was found to inhibit gastric emptying in olive oil-loaded mice at a dose of 200 mg/kg, per os (p.o.). The stereostructures of 1-5 were elucidated on the basis of chemical and spectroscopic evidence.     

Photoelectron and ultraviolet absorption spectra of allenyl vinyl ethers

The electronic structure of allenyl vinyl ethers (I) has been studied with the aid of photoelectron and UV spectroscopy, as well as MNDO and CNDO/S quantumchemical calculations. Divinyl ether has been selected as a model system for these molecules. The photoelectron spectra of I are similar to the spectrum of divinyl ether, with the exception of the band at 10.2–10.6 eV. The long-wavelength band in the UV spectra of I has been assigned to a transition localized in the allene group. The short-wavelength band of I corresponds to the ^* transition observed in divinyl ether.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2011–2014, September, 1989.     

Outdoor workers' acceptance of personal protective measures against solar ultraviolet radiation

The acceptance and usability of personal protection against solar UV radiation was evaluated in a field study with a group of tinsmiths in Austria. The personal protective measures (PPM) tested involved four categories: shirts, headwear, sunglasses and topically applied sunscreens; at least six different products per category were tested. Recommendations for the "ideal" shirt, headwear, pair of sunglasses and topical sunscreen are given based on data from questionnaires, i.e., from the point of view of the workers, independently from the actual physical level of protection (such as low transmittance or area of coverage) provided. It is argued that in practice it is important to consider the acceptance and usability of protective measures as well as the level of physical protection when providing PPM.     

Personal reflections on monochromators and action spectra for photoreactivation

This is a summary of work done, chiefly by the author, in the mid-20th century, when monochromators were a primary tool in identification of molecules involved in biological effects, much as spectrometers were useful for molecular chemistry in the 19th and early 20th centuries. Monochromator types are discussed, as well as production of action spectra fro the chromophores for photoreactivation of ultraviolet biological effects. Two new types of non-enzymatic photoreactivation were found in prokaryotes, in addition to the classical enzymatic photoreactivation.