scholarly journals Spectral tuning and evolution of primate short-wavelength-sensitive visual pigments

2011 ◽  
Vol 279 (1727) ◽  
pp. 387-393 ◽  
Author(s):  
Livia S. Carvalho ◽  
Wayne L. Davies ◽  
Phyllis R. Robinson ◽  
David M. Hunt
Keyword(s):  
Phylogenetic Analysis ◽  
Spectral Analysis ◽  
Short Wavelength ◽  
Primate Evolution ◽  
Visual Pigments ◽  
Uv Sensitivity ◽  
Tuning Mechanism ◽  
Initial Event ◽  
Primary Mechanism

The peak sensitivities ( λ max ) of the short-wavelength-sensitive-1 (SWS1) pigments in mammals range from the ultraviolet (UV) (360–400 nm) to the violet (400–450 nm) regions of the spectrum. In most cases, a UV or violet peak is determined by the residue present at site 86, with Phe conferring UV sensitivity (UVS) and either Ser, Tyr or Val causing a shift to violet wavelengths. In primates, however, the tuning mechanism of violet-sensitive (VS) pigments would appear to differ. In this study, we examine the tuning mechanisms of prosimian SWS1 pigments. One species, the aye-aye, possesses a pigment with Phe86 but in vitro spectral analysis reveals a VS rather than a UVS pigment. Other residues (Cys, Ser and Val) at site 86 in prosimians also gave VS pigments. Substitution at site 86 is not, therefore, the primary mechanism for the tuning of VS pigments in primates, and phylogenetic analysis indicates that substitutions at site 86 have occurred at least five times in primate evolution. The sole potential tuning site that is conserved in all primate VS pigments is Pro93, which when substituted by Thr (as found in mammalian UVS pigments) in the aye-aye pigment shifted the peak absorbance into the UV region with a λ max value at 371 nm. We, therefore, conclude that the tuning of VS pigments in primates depends on Pro93, not Tyr86 as in other mammals. However, it remains uncertain whether the initial event that gave rise to the VS pigment in the ancestral primate was achieved by a Thr93Pro or a Phe86Tyr substitution.

Synthesis and Anti-Tumor Activity Evaluation of Novel 7-Fluoro-4-(1- Piperazinyl) Quinolines

2019 ◽  
Vol 16 (6) ◽  
pp. 663-669
Author(s):  
Dan Liu ◽  
Aiqi Xue ◽  
Zhixin Liu ◽  
Yi Zhang ◽  
Penghui Peng ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Cancer Therapy ◽  
Carcinoma Cell ◽  
A549 Cells ◽  
Quinoline Derivatives ◽  
Human Carcinoma ◽  
Carcinoma Cell Lines ◽  
Human Carcinoma Cell ◽  
Anti Tumor Activity

Background: Three series of new 7-fluoro-4-(1-piperazinyl) quinolines (I1~I6, II1~II2 and IV1~IV4) were synthesized. Their anti-tumor activity was evaluated in vitro against three human carcinoma cell lines, namely SGC-7901 cells, BEL-7402 cells and A549 cells expressing high levels of EGFR by Methyl Thiazolyl Terazolium (MTT) assay. Methods: Three series of quinoline derivatives were synthesized, characterized and evaluated for their in vitro anti-tumor activities. Results and Discussion: Structures of the newly synthesized compounds were confirmed by spectral analysis. The preliminary bioassay indicated that compounds I1, I10 and II1 exhibited better anti-tumor activity than the rest of the target compounds and gefitinib against A549 cell based assay, which demonstrated that compounds I1, I10 and II1 are potential agents for cancer therapy. Results suggested that the substitutes on piperazinyl influenced anti-tumor activities remarkably. Conclusion: These results are useful for discovering more potent novel anti-tumor compounds and further studies are ongoing.

scholarly journals Insights into the Antioxidant Mechanism of Newly Synthesized Benzoxazinic Nitrones: In Vitro and In Silico Studies with DPPH Model Radical

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1224
Author(s):  
Stefania Marano ◽  
Cristina Minnelli ◽  
Lorenzo Ripani ◽  
Massimo Marcaccio ◽  
Emiliano Laudadio ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Epr Spectroscopy ◽  
Point Of View ◽  
Uv Spectrophotometry ◽  
Design And Synthesis ◽  
Antioxidant Mechanism ◽  
Primary Mechanism ◽  
In Silico Studies ◽  
Wide Range

Synthetic nitrone spin-traps are being explored as therapeutic agents for the treatment of a wide range of oxidative stress-related pathologies, including but not limited to stroke, cancer, cardiovascular, and neurodegenerative diseases. In this context, increasing efforts are currently being made to the design and synthesis of new nitrone-based compounds with enhanced efficacy. The most researched nitrones are surely the ones related to α-phenyl-tert-butylnitrone (PBN) and 5,5-dimethyl-1-pyrroline N-oxide (DMPO) derivatives, which have shown to possess potent biological activity in many experimental animal models. However, more recently, nitrones with a benzoxazinic structure (3-aryl-2H-benzo[1,4]oxazin-N-oxides) have been demonstrated to have superior antioxidant activity compared to PBN. In this study, two new benzoxazinic nitrones bearing an electron-withdrawing methoxycarbonyl group on the benzo moiety (in para and meta positions respect to the nitronyl function) were synthesized. Their in vitro antioxidant activity was evaluated by two cellular-based assays (inhibition of AAPH-induced human erythrocyte hemolysis and cell death in human retinal pigmented epithelium (ARPE-19) cells) and a chemical approach by means of the α,α-diphenyl-β-picrylhydrazyl (DPPH) scavenging assay, using both electron paramagnetic resonance (EPR) spectroscopy and UV spectrophotometry. A computational approach was also used to investigate their potential primary mechanism of antioxidant action, as well as to rationalize the effect of functionalization on the nitrones reactivity toward DPPH, chosen as model radical in this study. Further insights were also gathered by exploring the nitrone electrochemical properties via cyclic voltammetry and by studying their kinetic behavior by means of EPR spectroscopy. Results showed that the introduction of an electron-withdrawing group in the phenyl moiety in the para position significantly increased the antioxidant capacity of benzoxazinic nitrones both in cell and cell-free systems. From the mechanistic point of view, the calculated results closely matched the experimental findings, strongly suggesting that the H-atom transfer (HAT) is likely to be the primary mechanism in the DPPH quenching.

Interaction of Neutrophils with Endothelial Cells, Fibroblasts and Their Extracellular Matrices: Microscopic and Computerised Analysis

1988 ◽  
Vol 16 (1) ◽  
pp. 48-53
Author(s):  
Marina Ziche ◽  
Lucia Morbidelli ◽  
Annalisa Rubino ◽  
Piero Dolara ◽  
Stefano Bianchi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Image Analysis ◽  
Vascular Endothelial Cells ◽  
Extracellular Matrices ◽  
Polymorphonuclear Neutrophil ◽  
Initial Event ◽  
Computerised Image Analysis ◽  
Capillary Endothelial Cells ◽  
Vitro Model

Polymorphonuclear neutrophil (PMN) interaction with vascular endothelial cells is the initial event in the migration of neutrophils through blood vessel walls before reaching inflammation sites in tissues. The interaction between fibroblasts and endothelial cells and their extracellular matrices might be modulated by the activation of neutrophils that occurs at inflammatory reaction sites. We have used an in vitro model to study PMN function, measuring the adhesion of human PMNs to capillary endothelial cells and fibroblasts grown in culture and to their extracellular matrices. The interaction was measured in basal conditions and in the presence of the chemotactic effector, formyl-methionyl-leucyl-phenylalanine (FMLP at the concentration of 10 7M). Adhesion was expressed by the number of adherent PMNs/mm2 on a histological specimen. Moreover, we have adapted a program for image analysis to quantify neutrophil adhesion. Three times more PMNs adhered to matrices than to monolayers, and adherence could be increased by the presence of 10-7M FMLP, except in the case of fibroblast monolayers. We found a good correlation between microscopic observation and computerised image analysis measuring PMN adhesiveness to extracellular matrices.

scholarly journals Phylogenetic analysis and predicted functional effect of protein mutations of E6 and E7 HPV16 strains isolated in Indonesia

2015 ◽  
Vol 24 (4) ◽  
pp. 197-205
Author(s):  
Dwi Wulandari ◽  
Lisnawati Rachmadi ◽  
Tjahjani M. Sudiro
Keyword(s):  
Amino Acids ◽  
Phylogenetic Analysis ◽  
Amino Acid ◽  
Asian American ◽  
Protein Function ◽  
Single Amino Acid ◽  
Hpv16 E6 ◽  
E6 And E7 ◽  
Neutral Mutations

Background: E6 and E7 are oncoproteins of HPV16. Natural amino acid variation in HPV16 E6 can alter its carcinogenic potential. The aim of this study was to analyze phylogenetically E6 and E7 genes and proteins of HPV16 from Indonesia and predict the effects of single amino acid substitution on protein function. This analysis could be used to reduce time, effort, and research cost as initial screening in selection of protein or isolates to be tested in vitro or in vivo.Methods: In this study, E6 and E7 gene sequences were obtained from 12 samples of  Indonesian isolates, which  were compared with HPV16R (prototype) and 6 standard isolates in the category of European (E), Asian (As), Asian-American (AA), African-1 (Af-1), African-2 (Af-2), and North American (NA) branch from Genbank. Bioedit v.7.0.0 was used to analyze the composition and substitution of single amino acids. Phylogenetic analysis of E6 and E7 genes and proteins was performed using Clustal X (1.81) and NJPLOT softwares. Effects of single amino acid substitutions on protein function of E6 and E7 were analysed by SNAP.Results: Java variants and isolate ui66* belonged to European branch, while the others belonged to Asian and African branches. Twelve changes of amino acids were found in E6 and one in E7 proteins. SNAP analysis showed two non neutral mutations, i.e. R10I and C63G in E6 proteins. R10I mutations were found in Af-2 genotype (AF472509) and Indonesian isolates (Af2*), while C63G mutation was found only in Af2*.Conclusion: E6 proteins of HPV16 variants were more variable than E7. SNAP analysis showed that only E6 protein of African-2 branch had functional differences compared to HPV16R.

scholarly journals Species Identification and Antifungal Susceptibility Patterns of Species Belonging to Aspergillus Section Nigri

2009 ◽  
Vol 53 (10) ◽  
pp. 4514-4517 ◽  
Author(s):  
Laura Alcazar-Fuoli ◽  
Emilia Mellado ◽  
Ana Alastruey-Izquierdo ◽  
Manuel Cuenca-Estrella ◽  
Juan L. Rodriguez-Tudela
Keyword(s):  
Phylogenetic Analysis ◽  
Species Identification ◽  
Antifungal Susceptibility ◽  
Morphological Features ◽  
Correct Classification ◽  
Paradoxical Effect ◽  
Aspergillus Section Nigri ◽  
Susceptibility Patterns ◽  
Aspergillus Section

ABSTRACT A phylogenetic analysis was performed for 34 Aspergillus strains belonging to section Nigri. Molecular methods allowed for the correct classification into three different clades (A. niger, A. tubingensis, and A. foetidus). Correlation with in vitro itraconazole susceptibility distinguished the following three profiles: susceptible, resistant, and showing a paradoxical effect. A number of different species whose morphological features resemble those of A. niger showed unusual MICs to itraconazole that have never been described for the Aspergillus genus.

scholarly journals Differential Binding and Neutralization of Activins A and B by Follistatin and Follistatin Like-3 (FSTL-3/FSRP/FLRG)

Endocrinology ◽  
2003 ◽  
Vol 144 (5) ◽  
pp. 1671-1674 ◽  
Author(s):  
Alan Schneyer ◽  
Amy Schoen ◽  
Alicia Quigg ◽  
Yisrael Sidis
Keyword(s):  
Biological Activity ◽  
Mechanism Of Action ◽  
Relative Activity ◽  
Activin A ◽  
Primary Mechanism ◽  
Wide Availability ◽  
Reporter Assays ◽  
Differential Binding ◽  
Tgfβ Superfamily

Modulation of activin and other TGFβ superfamily signaling is the primary mechanism of action for both follistatin (FS) and FS-like 3 (FSTL-3). However, most studies of these ligands use activin A due to its wide availability. We have now tested the ability of FS288 and FSTL-3 to bind and neutralize activin B relative to activin A. Activin B bound to both FS and FSTL-3 at a potency approximately 10-fold lower than that of activin A. Moreover, whereas both activins had similar biological activity in 293 cell reporter assays, FS and FSTL-3 were approximately 3-fold more effective in neutralizing activin A relative to activin B. These results suggest that neutralization of activins A and B by FS and FSTL-3 are not identical, so that the relative activity of each activin in tissues where both are produced, such as in the ovary, could be quite different. In addition, biological systems that use primarily activin B, but which have been examined in vitro using activin A, may need to be reevaluated to determine the actual physiologic roles of FS or FSTL-3.

scholarly journals Ultraviolet-sensitive vision in long-lived birds

2010 ◽  
Vol 278 (1702) ◽  
pp. 107-114 ◽  
Author(s):  
Livia S. Carvalho ◽  
Ben Knott ◽  
Mathew L. Berg ◽  
Andrew T. D. Bennett ◽  
David M. Hunt
Keyword(s):  
Uv Light ◽  
Bird Species ◽  
Visual Sensitivity ◽  
Opsin Gene ◽  
Uv Sensitivity ◽  
Long Period ◽  
Lens Transparency ◽  
Avian Order

Long-term exposure to ultraviolet (UV) light generates substantial damage, and in mammals, visual sensitivity to UV is restricted to short-lived diurnal rodents and certain marsupials. In humans, the cornea and lens absorb all UV-A and most of the terrestrial UV-B radiation, preventing the reactive and damaging shorter wavelengths from reaching the retina. This is not the case in certain species of long-lived diurnal birds, which possess UV-sensitive (UVS) visual pigments, maximally sensitive below 400 nm. The Order Psittaciformes contains some of the longest lived bird species, and the two species examined so far have been shown to possess UVS pigments. The objective of this study was to investigate the prevalence of UVS pigments across long-lived parrots, macaws and cockatoos, and therefore assess whether they need to cope with the accumulated effects of exposure to UV-A and UV-B over a long period of time. Sequences from the SWS1 opsin gene revealed that all 14 species investigated possess a key substitution that has been shown to determine a UVS pigment. Furthermore, in vitro regeneration data, and lens transparency, corroborate the molecular findings of UV sensitivity. Our findings thus support the claim that the Psittaciformes are the only avian Order in which UVS pigments are ubiquitous, and indicate that these long-lived birds have UV sensitivity, despite the risks of photodamage.

scholarly journals Unveiling Monoterpene Biosynthesis in Taiwania cryptomerioides via Functional Characterization

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2404
Author(s):  
Li-Ting Ma ◽  
Pi-Ling Liu ◽  
Yang-Tui Cheng ◽  
Tz-Fan Shiu ◽  
Fang-Hua Chu
Keyword(s):  
Phylogenetic Analysis ◽  
Functional Characterization ◽  
In Vitro Assay ◽  
Conifer Species ◽  
Vitro Assay ◽  
Catalytic Residues ◽  
Monoterpene Synthase ◽  
Monoterpene Biosynthesis ◽  
Taiwania Cryptomerioides

Taiwania cryptomerioides is a monotypic species, and its terpenoid-rich property has been reported in recent years. To uncover monoterpene biosynthesis in T. cryptomerioides, this study used transcriptome mining to identify candidates with tentative monoterpene synthase activity. Along with the phylogenetic analysis and in vitro assay, two geraniol synthases (TcTPS13 and TcTPS14), a linalool synthase (TcTPS15), and a β-pinene synthase (TcTPS16), were functionally characterized. Via the comparison of catalytic residues, the Cys/Ser at region 1 might be crucial in determining the formation of α-pinene or β-pinene. In addition, the Cupressaceae monoterpene synthases were phylogenetically clustered together; they are unique and different from those of published conifer species. In summary, this study aimed to uncover the ambiguous monoterpenoid network in T. cryptomerioide, which would expand the landscape of monoterpene biosynthesis in Cupressaceae species.

Regulation of Photoactivation in Vertebrate Short Wavelength Visual Pigments:  Protonation of the Retinylidene Schiff Base and a Counterion Switch

Biochemistry ◽  
2007 ◽  
Vol 46 (18) ◽  
pp. 5330-5340 ◽  
Author(s):  
Lavoisier S. Ramos ◽  
Min-Hsuan Chen ◽  
Barry E. Knox ◽  
Robert R. Birge
Keyword(s):  
Schiff Base ◽  
Short Wavelength ◽  
Visual Pigments

PTSA-Catalyzed One Pot Domino Synthesis of Dihydropyrido[2,3-d]pyrimidine Derivatives and their Antimicrobial Activity

2021 ◽  
Vol 6 (3) ◽  
pp. 222-227
Author(s):  
Krishna A. Bhensdadia ◽  
Prakash L. Kalavadiya ◽  
Nilam H. Lalavani ◽  
Shipra H. Baluja
Keyword(s):  
Antimicrobial Activity ◽  
Spectral Analysis ◽  
Pyrimidine Derivatives ◽  
One Pot ◽  
In Vitro Antimicrobial Activity ◽  
Aryl Aldehydes ◽  
Three Component Reaction ◽  
The One

A novel series of dihydropyrido[2,3-d]pyrimidine derivatives were synthesized by multicomponent domino cyclization via the one-pot three component reaction of 6-amino uracil, substituted aryl aldehydes and N-methyl-1-(methylthio)-2-nitroethenamine in the presence of PTSA 10 mol% as a catalyst. The structures of these synthesized compounds were characterized by spectral analysis. Further the synthesized compounds screened for in vitro antimicrobial activity. Among all the compounds, compound 4b containing flouro substitution exhibited good inhibition against the tested species.

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