Cardiac Condition Detection using Artificial Neural Networks

P a g e | 2 Table of Contents Abstract......................................................................................................................................................... 5 Introduction/Background.............................................................................................................................

The stereochemistry of dehydro-[Beta]-carotene. Studies on the interaction of some carotenoids with boron trifluoride and N-bromosuccinimide. Provitamin A activity of a C41-carotenoid

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. An extensive study of the stereoisomerization of dehydro-[Beta]-carotene is presented. Two of the cis isomers have been isolated in crystalline form and described. The nature of "isocarotene" has been clarified. Treatment of [Beta]-carotene with boron trifluoride under defined conditions leads chiefly either to its stereoisomerization or chemical conversion. Two of the several conversion products have been crystallized; a third, exhibiting strong fluorescence in ultraviolet light is also described. Three new carotenoids, termed isocryptoxanthin, isocryptoxanthin methyl ether, and dimethoxy-[Beta]-carotene, formed by the addition of water or methanol to dehydro-[Beta]-carotene in the presence of boron trifluoride are described. The structures of the first two compounds have been determined; the location of the substituent groups in the third is, at present, uncertain. Dehydro-[Beta]-carotene, bisdehydro-[Beta]-carotene, and anhydroeschscholtzxanthin have been isolated from the end products of the reaction of [Beta]-carotene with N-bromosuccinimide. Bisdehydro-[Beta]-carotene is a new carotenoid whose probable structure is discussed. The considerable provitamin A potency of 16,16'-homo-[Beta]-carotene is discussed from the standpoint of its novel structural features

A Study of Some cis—trans Isomeric Dehydro-β-carotenes

Dehydro-β-carotene samples obtained from β-carotene constitute mixtures of stereoisomers from which two main crystalline cis forms were isolated. The interconversion of members of this stereoisomeric set was studied by thermic, photochemical and catalytic methods. The mixtures thus obtained contain less of the all-trans compound than in the case of carotenes. One of the observed cis dehydro-β-carotenes showed a degraded spectrum. No distinct cis-peak phenomena were observed in this "retro” system

Action of N-Bromosuccinimide on β-Carotene

β-Carotene when refluxed with N-bromosuccinimide yields a complicated pigment mixture from which three compounds have been isolated in pure state, viz., dehydro-β-carotene, C_(40)H_(54), bisdehydro-β-carotene, C_(40)H_(52), and a pigment very probably identical with anhydro-eschscholtzxanthin, C_(40)H_(50). Some spectral and stereochemical observations are discussed

Conversion of Dehydro-β-carotene, via its Boron Trifluoride Complex, into an Isomer of Cryptoxanthin

Dehydro-β-carotene and BF_3-etherate form a dark blue complex. Cleavage with water (or methanol) resulted in the isolation of a monohydroxy-β-carotene, termed isocryptoxanthin (or its methyl ether). Isocryptoxanthin when treated with acid chloroform undergoes dehydration to yield dehydro-β-carotene which indicates the presence of an allylic hydroxyl group. While naturally occurring cryptoxanthin is 3-hydroxy-β-carotene, isocryptoxanthin is the corresponding 4-compound. Its methyl ether or acetate can also be converted into dehydro-β-carotene

A Study of Some cis—trans Isomeric Dehydro-β-carotenes

Dehydro-β-carotene samples obtained from β-carotene constitute mixtures of stereoisomers from which two main crystalline cis forms were isolated. The interconversion of members of this stereoisomeric set was studied by thermic, photochemical and catalytic methods. The mixtures thus obtained contain less of the all-trans compound than in the case of carotenes. One of the observed cis dehydro-β-carotenes showed a degraded spectrum. No distinct cis-peak phenomena were observed in this "retro” system

Conversion of Dehydro-β-carotene, via its Boron Trifluoride Complex, into an Isomer of Cryptoxanthin

Dehydro-β-carotene and BF_3-etherate form a dark blue complex. Cleavage with water (or methanol) resulted in the isolation of a monohydroxy-β-carotene, termed isocryptoxanthin (or its methyl ether). Isocryptoxanthin when treated with acid chloroform undergoes dehydration to yield dehydro-β-carotene which indicates the presence of an allylic hydroxyl group. While naturally occurring cryptoxanthin is 3-hydroxy-β-carotene, isocryptoxanthin is the corresponding 4-compound. Its methyl ether or acetate can also be converted into dehydro-β-carotene