Biological activity oxidation

Mudd, Mudd et Menzel, and Nasr et have reported that ozonization of aqueous solutions of NADH or NADPH results in their oxidation. However, there is a difference in their findings as to whether the resulting product is a biologically active oxidized pyridine nudeotide (NAD or NADP), as suggested by Menzel, or is molecularly disrupted to the extent that it is unable to participate in enzymatic processes. Inasmuch as more drastic effects are likely to be observed in vitroy it is more likely that oxidation of intracellular reduced pyridine nucleotides proceeds mainly to NAD or NADP after ozone inhalation but further resolution of this question would be of value. 

V(IV) is a biologically active oxidation state, acting as an electron-transfer mediator in enzymes such as amavadine, which catalyzes the formation of disulfides [65]. Amavadin is a V(IV) complex found in mushrooms of... 

Reduced nicotinamides are readily oxidized by PAN (31). Since the products form cyanide complexes with characteristic UV spectra and also react in a predictable fashion with specific dehydrogenases, they have been characterized as the biologically active oxidized forms of the coenzymes (31). A different reaction of PAN is with ethylenic double... 

In the mitogenic bioassay, the KGF control had maximal activity around 34,000 cpm (Figure 5). To achieve 40% maximal activity in the bioassay (about 13,600 cpm), the KGF control required about 2 ng/ml and the KGF species with Met 28 and Met 60 oxidized required 6 ng/ml. However, to achieve this level of activiy in KGF with Met 28, Met 60, and Met 160 oxidized required about 2 pg/ml. KGF with Met 28, Met 60, and Met 160 oxidized lost significant biological activity. Oxidation of Met 160 in KGF to methionine... 

Fluorometric Methods. One of the most specific methods for the determination of ascorbic acid and its biologically active oxidation product, dehydroascorbic acid, is the fluorometric method introduced by Deutsch and Weeks (43), which is an official AOAC method (44). It is... 

Kadi, A., Bochkov, V. N., Huber, J. and Leitinger, N. Apoptotic cells as sources for biologically active oxidized phosphohpids. Antioxid Redox Signal 6 (2004) 311-320. 

Huber, J. et al. Oxidized membrane vesicles and blebs from apoptotic cells contain biologically active oxidized phospholipids that induce monocyte-endothelial interactions. Arter-ioscler Thromb VAsc Biol 22 (2002) 101-7. 

Huber, J., Vales, A., Mitulovic, G., Blumer, M., Schmid, R., Witztum, J.L., Binder, B.R., and Leitinger, N. 2002. Oxidized membrane vesicles and blebs from apoptotic cells contain biologically active oxidized phospholipids that induce monocyte-endothelial interactions. Artenoscler. Thromb. Vase. Biol. 22, 101-107. 

A BET study of tetrasulfophthalocyanine as a model for a biologically active oxidant, in TMOS gels [96] revealed specific areas between 400 g to 700 g ... 

Therapeutics. Compounds containing the furan or tetrahydrofuran ring are biologically active and are present in a number of pharmaceutical products. Eurfurjdamine [617-89-0] is an intermediate in the diuretic, furosemide. Tetrahydrofurfurylamine [4795-29-3] may also have pharmaceutical applications. 5-(E)imethyiaininomethyi)furfuryi alcohol [15433-79-17 is an intermediate in the preparation of ranitidine, which is used for treating ulcers. 2-Acet5dfuran [1192-62-7] prepared from acetic anhydride and furan is an intermediate in the synthesis of cefuroxime, a penicillin derivative. 2-Euroic acid is prepared by the oxidation of furfural. Both furoic acid [88-14-2] and furoyl chloride [527-69-5] are used as pharmaceutical intermediates. 

Sulfoxide hGH. Methionine residues in proteins are susceptible to oxidation primarily to the sulfoxide. Both pituitary-derived and biosynthetic hGH undergo sulfoxidations at Met-14 and Met-125 (29). Oxidation at Met-170 has also been reported in pituitary but not biosynthetic hGH. Both desamido hGH and Met-14 sulfoxide hGH exhibit full biological activity (29). 

The reactivity of the individual O—P insecticides is determined by the magnitude of the electrophilic character of the phosphoms atom, the strength of the bond P—X, and the steric effects of the substituents. The electrophilic nature of the central P atom is determined by the relative positions of the shared electron pairs, between atoms bonded to phosphoms, and is a function of the relative electronegativities of the two atoms in each bond (P, 2.1 O, 3.5 S, 2.5 N, 3.0 and C, 2.5). Therefore, it is clear that in phosphate esters (P=0) the phosphoms is much more electrophilic and these are more reactive than phosphorothioate esters (P=S). The latter generally are so stable as to be relatively unreactive with AChE. They owe their biological activity to m vivo oxidation by a microsomal oxidase, a reaction that takes place in insect gut and fat body tissues and in the mammalian Hver. A typical example is the oxidation of parathion (61) to paraoxon [311-45-5] (110). 

Similar heterogeneous reactions also can occur, but somewhat less efticientiy, in the lower stratosphere on global sulfate clouds (ie, aerosols of sulfuric acid), which are formed by oxidation of SO2 and COS from volcanic and biological activity, respectively (80). The effect is most pronounced in the colder regions of the stratosphere at high latitudes. Indeed, the sulfate aerosols resulting from emptions of El Chicon in 1982 and Mt. Pinatubo in 1991 have been impHcated in subsequent reduced ozone concentrations (85). 

Much effort has been placed in the synthesis of compounds possessing a chiral center at the phosphoms atom, particularly three- and four-coordinate compounds such as tertiary phosphines, phosphine oxides, phosphonates, phosphinates, and phosphate esters (11). Some enantiomers are known to exhibit a variety of biological activities and are therefore of interest Oas agricultural chemicals, pharmaceuticals (qv), etc. Homochiral bisphosphines are commonly used in catalytic asymmetric syntheses providing good enantioselectivities (see also Nucleic acids). Excellent reviews of low coordinate (coordination numbers 1 and 2) phosphoms compounds are available (12). 

The stereocontroUed syntheses of steroid side chains for ecdysone, cmstecdysone, brassinoHde, withanoHde, and vitamin D have been reviewed (185). Also, other manuscripts, including reviews on the partial synthesis of steroids (186), steroid dmgs (187—189), biologically active steroids (190), heterocychc steroids (191), vitamin D (192), novel oxidations of steroids (193), and template-directed functionali2ation of steroids (194), have been pubhshed. 

This synthesis was the first step toward industrial vitamin production, which began in 1936. The synthetic product was shown to have the same biological activity as the natural substance. It is reversibly oxidized in the body to dehydro-L-ascorbic acid (3) (L-// fi (9-2,3-hexodiulosonic acid y-lactone), a potent antiscorbutic agent with hiU vitamin activity. In 1937, Haworth and Szent-Gyn rgyi received the Nobel Prize for their work on vitamin C. 

The thiol form (12) is susceptible to oxidation (see Fig. 2). Iodine treatment regenerates thiamine in good yield. Heating an aqueous solution at pH 8 in air gives rise to thiamine disulfide [67-16-3] (21), thiochrome (14), and other products (22). The disulfide is readily reduced to thiamine in vivo and is as biologically active. Other mixed disulfides, of interest as fat-soluble forms, are formed from thiamine, possibly via oxidative coupling to the thiol form (12). 

X = NH2, Y = H). Oxidation (54) of tetracyclines usiag the Udenfriend reagent has yielded 9-hydroxytetracyclines and disubstituted (C-7 and C-9) products (48) can also be obtained. Substituent assignments are made from nmr spectral iaterpretations. The 7- and 9-methyl tetracyclines have been prepared and reported to retain biological activity (55). 

Benzo[b]thiophene-2,3-quinone, 5-chloro-oxidation, 4, 824 Benzothiophenes, 4, 863-934 biological activity, 4, 911-913 intramolecular acylation, 4, 761 mass spectrometry, 4, 739 metabolism, 1, 242 phosphorescence, 4, 16 reactivity, 4, 741-861 spectroscopy, 4, 713-740 structure, 4, 713-740 substituents reactivity, 4, 796-839... 

Folic acid, 5-methyltetrahydro-biological activity, 3, 325 oxidation, 3, 308 Folic acid, iV-nitroso-carcinogenicity, 1, 141 Folic acid, 10-oxa-synthesis, 3, 327 Folic acid, 4-piperidyl-hydrolysis, 3, 294 Folic acid, 5,6,7,8-tetrahydro-chirality, 3, 281 synthesis, 1, 161 Folic acid, 10-thio-synthesis, 3, 327... 

---