34 resultados para Fluorescent Brightener 28
em Brock University, Canada
Resumo:
To further understand in vivo localization and trafficking of a-tocopherol (a-Toe), the most biologically active form of vitamin E, between lipid environments, tocopherols are required that can be followed by teclu1iques such as confocal microscopy and fluorescence resonance energy transfer (FRET) assays. To this end, sixteen fluorescent analogues of a-tocopherol (la-d [(1)anthroy loxy -a-tocopherols, A O-a-Toes], 2a-d [w-nitro benzoxadiazole-a-tocopherols, NBD-aToes], 3a-d [w-dansyl-a-tocopherols, DAN-a-Toes], and 4a-d [w-N-methylanthranilamide-atocopherols, NMA-a-TocsD were prepared by substituting fluorescent labels at the terminus of w-functionalized alkyl chains extending from C-2 of the chroman ring while retaining key binding features of the natural ligand. These compounds were prepared starting from (S)-Trolox® acid VIa esterification, protection, and reduction producing the silyl-protected (S)-Trolox aldehyde that was coupled using Wittig chemistry to different w-hydroxyalkylphosphonium bromides. Reduction of the alkene generated the w-hydroxy functionalized 2-n-alkyl intermediates 9a-d having the necessary 2R stereochemistry. A series of functional group manipulations including mesylation, substitution with azide, and hydride reduction provided w-amino functionalized intermediates 12a-d as well. Coupling intermediates 9a-d and 12a-d with the selected fluorophores (9- anthracene carboxylic acid, 4-chloro-7-nitrobenz-2-oxa-l,3-diazole, 5- dimethylaminonapthalene-l-sulfonyl chloride, and I-methyl-2H-3,1-benzoxazine-2,4(1H)dione), followed by deprotection of the phenolic silyl group, gave the desired fluorescent ligands la-d, 2a-d, 3a-d and 4a-d in good yield. Assessment of their binding affinities with recombinant human a-tocopherol transfer protein (ha-TTP) utilizing fluorescent titration binding assays identified competent ligands for further use in protein studies. Compounds Id (C9-AO-a-Toc) and 2d (C9-NBD-a-Toc) both having nonyl alkyl chain extensions between the chromanol and fluorophore were shown to bind specifically to ha-TTP with dissociation constants (KdS) of approximately 280 nM and 55 nM respectively, as compared to 25 nM for the natural ligand 2R,4'R,^'R-a-tocophQxoL.
Resumo:
Since its discovery in 1922, vitamin E has been widely investigated for its role as a powerful, chain-breaking antioxidant that is required for human health. However, some basic issues still remain unclear, such as the mechanism and dynamics of the intracellular trafficking of a-tocopherol. To better understand tocopherol's biological activity at the cellular level, fluorescence spectroscopy and microscopy have been found to be valuable tools. This thesis reports the synthesis of a new fluorescent analogue of a-tocopherol, atocohexaenol, an intrinsically fluorescent analogue of a-tocopherol. Different methodologies of preparation have been attempted and a strategy using a preformed chromanol head plus ClO and Cs portion of the polyene side chain finally provided us the desired a-tocohexaenol. a-Tocohexaenol shows a strong fluorescence in both ethanol and hexanes with maximum Aab = 368 nm and maximum /...em = 521 nm. This compound is stable for a couple of weeks in ethanol or hexane solution if stored at 0 °C and protected form light. It decomposes slowly at room temperature and light will accelerate its decomposition (within 5 hours). Thus, a-Tocohexaenol may be a useful fluorescent probe to study the biochemistry and cell biology of vitamin E.
Resumo:
Transcript (spelling and grammar retained): Chippawa [Chippewa] 28th August 1860 My Dear Sir I duly received your very kind letter of the 24th [June] asking me to communicate such facts of general interest connected with my career during the War with the United States. I have no objection to afford you such information as came under my own observation; nevertheless I do so, with the understanding, I have no desire to be my own trumpeter. With respect to your circular wherein you state you have been for several years collecting materials for a History of the late War between the United States & Great Britain, for which you are now gathering further materials to add to your collection, concerning the Second War for Independence. I am rather at a loss to know, what is meant by the second war; If you allude to the petty Rebellion, it could not be called a War, Those that caused the outbreak were very soon put down, by the Loyal people of the Province without the aid of Regular Troops being satisfied with the Independence they enjoyed. With respect to the several questions names in your circular: To the 1st I would say, this locality is made memorable by the battle of Chippawa [Chippewa] which took place about a mile above the village on the ground I pointed out to you, when I had the pleasure of seeing you a few days ago, with Mr Porter of the Niagara Falls, of which I believe you took sketches at the time. 2nd I have no historical documents of any value; so many years having gone past, the most of my old papers have either been lost or destroyed, I however came across two letters, one dated Queenston 9th July 1812 from Lt. Col. Nicholl Quarter Master General of Militia, the other from Lt. Col Myers Deputy Quarter Master General of the Regular Army date Fort George 23rd same month, directed to me in the hand writing of each of those officers as Deputy Quarter Master General of Militia, which letters I shall be obliged you would return at as early a day possible, as I wish to place them with tome others in the case, I have had made to hold the cocked hat & feather I wore during that eventful period, which I am sorry I did not exhibit when you was at my house; with reference to it I now enclose a letter from Lt. Col. Clark, residing at Port Dalhousie he was Captain & Adjutant of Militia in the War of 1812__ I send the letter in proof of the cock’d hat it is a lengthy one, but you may find time to turn over it, as I shall also place it in the hat case__ 3rd Where are [but] [for] traditionary [sic] witnesses residing in this vicinity – Col Clark above named Mr Merritt of St. Catharines, & Mr Kerby of Brantford are the only ones I now recollect, who could offord [sic] you any statistical information. 4th I have no pictorial sketches of any Military Movements or fortifications. As regards my own career, which you appear [ ? ] of knowing__ I was first a Lieutenant in a volunteer flank company stationed on the river side opposite [Navy] Island not far from the battle ground of Chippawa [Chippewa], I got promotion as Lieutenant of Cavalry before I got my Cavalry dress completed in three days more, I was called by General Brock to Fort George, was appointed Deputy Quarter Master General of Militia with the rank of Captain s the accompanying letters will show. I was at the battle of Stony Creek, several skirmishes at the Cross Roads, when the American army [ ? ] Fort George, at the taking of Col. Boerstler at the Beaver Dam, & had the honor of receiving Colonel Chapens sword at the surrender, who commanded a company of volunteer Horse Men was at the taking of 15 regulars & two officers at Fort Schlosser—was with Col. Bishop at the taking of Black Rock, near him when he fell, three men of the 8th Reg. more killed in the Boat I was in – I was at Chippawa battle, and the last, not the least in Lundy’s lane battle, which the Americans call the battle of Bridge [Waters]. I had forgot; there was another small affair at Corks Mill where I was. I could write a little history of events, but have not the time to do so. If what I have stated will be of any service for the purpose you require I shall feel happy. The history of the late War was published at Toronto in the Anglo American Magazine. Did you ever see it, I have the Books, there were however several errors which came under my notice, which I could have corrected. If my time would permit I could give you a more detailed statement of events. I trust however you may succeed with your publication , and I shall be most happy to hear from you at all times—I related many little occurances verbally to you when here, which I thought not necessary to repeat again as you would have a perfect recollection of them. Be pleased to return the letters for the purpose I require them. I am My Dear Sir Your respectful friend James Cummings
Resumo:
Transcript [original spelling and grammar retained]: Albany June 28 1812 Sir Your letter of the 23d has been received. I had anticipated your request by ordering the detachment from Washington, Essex, Clinton and Franklin Counties into service and have fixed the days and places of their Rendezvous. Upon application to the quarter master General I find there are but 139 tents & 60 camp kettles at this place & even those I take by a kind of stealth. The Deputy Quarter Master General declines giving an order for their delivery until he shall have a written order from the Quarter Master General, and the latter is willing I Shall take them but will not give the Deputy a written order for that purpose. Under Such circumstances I shall avail myself of the rule of Possession and by virtue of the Eleven Points of Law Send them tomorrow morning without a written order from anyone. You may remember that when you were Secretary of the war department I invited you to forward and deposit in our Frontier Arsenals, arms ammunition and camp equipage free of expense to be ready in case of war and the same invitation to the war department has been repeated some time, Since The United States have now from 5 to 600 regular troops at Plattsburgh, Rome, Canandaigua & c, where those arsenals are, and yet those recruits are now and must be for weeks to come unarmed and unequipped in every respect although within musket Shot of arsenals. The recruits at Plattsburgh are within 50 miles of two tribes of Canadian Indians. In case of an attack upon the Frontiers that portion of the United States army would be as inefficient and unable to defend the inhabitants or themselves even. The Militia Detachments on the Western Frontiers received the news of war with [cherafulness] and determined courage, and I am happy to find they are united late brothers, highly improved in Discipline & ready to devote themselves to any Service or danger which the good of the Country may require. But they are in barracks from which they cannot move a days march for the want of tents and other equipage, and they are in Separate and Independent Detachments without a General Officer to command them or combine their exertions for the accomplishment of any desirable and important object. The only officer of the United States here who can do anything is the Quarter Master General and he has not a tent Camp Kettle or Knapsack in this arsenal except what I have concluded to send off tomorrow morning as above mentioned to furnish men As to Cannon Muskets and Ammunition. I can find now one here who will exercise any authority over them or deliver a Single article upon my requisition. Neither can I find any Officer of the army who feel himself authorized to exercise any authority or do any act which will aid me in the all important object of protecting the Inhabitants of an extended Frontier exposed to the Cruelties of Savages and the depredations of the enemy. If I must rely upon the Militia Solely for Such protection I entreat you to give orders to your Officers to furnish upon my orders, for the use of the Militia Detachments , all needful weapons and articles with which the United States are Supplied and of which we are destitute . You may rely upon all the assistance which my talents, influence or authority can furnish in the active prosecution of the first & necessary way which has been declared by the Constituted Authorities of our beloved Country. I am, Sir, respectfully Your ob. Servt. Daniel D. Tompkins
Resumo:
Volumes of interest were published between 1812 and 1815 with articles about the War of 1812.
Resumo:
Volumes of interest were published between 1812 and 1815 with articles about the War of 1812.
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Volumes of interest were published between 1812 and 1815 with articles about the War of 1812.
Resumo:
Volumes of interest were published between 1812 and 1815 with articles about the War of 1812.
Resumo:
An invoice for goods bought in Port Robinson, 28, May 1838. The list of goods includes: Blue cloth, buttons & thread, high lace shoes etc. There is also a note which reads "To Mr. W. Cowen, Dear Sir, The above is the quantity of goods you wanted and as ---- the quality as may be. I hope they will suit him. I have not all the ------- for the vest & pant above, but have sent what I have. I could not procure a silk handkerchief of any kind. I think Mr. Donaldson will be up soon he is now at Toronto. Give my compliments to Mrs. Cowan & family no more at present" Robert Elliot
Resumo:
The letter discusses the capture of Cantigny. There are three article clippings attached to the letter describing "Cantigny Fighting Cited", "Co-operation at Cantigny", "The fight at Cantigny...". Eleanore Celeste mentions the number of troops that are said to be arriving weekly (100,000) and that there are 1,000,000 over there now." This letter is labelled number 120.