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Hydroxyethyl spectrum

Hydroxy-8-hydroxyethyl-6,7-dimethyl-2-pteridinone has been shown to have the same absorption spectrum in alkaline solution as its 1,7-dihydro derivative, namely peaks at 231, 283, and 316 mp. This... [Pg.30]

Figure 19. Correlations in the HSQC-1,1-ADEQUATE spectrum allow the overlapped resonances of the 2-(p-hydroxyethyl)piperidine moiety incorporated in the structure to be assigned (Figures 20 and 21). There are, however, resonance overlaps that complicate the F1SQC-1,1-ADEQUATE spectrum by virtue of artefact responses contained in the spectrum that are enclosed in boxes in Figure 21. Given the considerable overlap in the proton spectrum, the presence of artefact responses in the GIC processed HSQC-1,1-ADEQUATE spectrum is not surprising. It is also somewhat uncertain whether or not the 1,1-ADEQUATE spectrum itself would be tractable because of the proton resonance overlaps. Figure 19. Correlations in the HSQC-1,1-ADEQUATE spectrum allow the overlapped resonances of the 2-(p-hydroxyethyl)piperidine moiety incorporated in the structure to be assigned (Figures 20 and 21). There are, however, resonance overlaps that complicate the F1SQC-1,1-ADEQUATE spectrum by virtue of artefact responses contained in the spectrum that are enclosed in boxes in Figure 21. Given the considerable overlap in the proton spectrum, the presence of artefact responses in the GIC processed HSQC-1,1-ADEQUATE spectrum is not surprising. It is also somewhat uncertain whether or not the 1,1-ADEQUATE spectrum itself would be tractable because of the proton resonance overlaps.
The 13C-n.m.r. spectrum of 0-(2-hydroxyethyl)cellulose partly degraded enzymically (d.s. 0.8) in D20 at 30° (see Fig. 39,B) was similar, except for the region arising from the substituent, which is [-0-(CH2-CH2-0) -CH2-CH20] with n = 2 or 3. Because the spectral shifts occurring on 0-(2-hydroxyethyl)ation are close to those caused by O-(carboxymethyl)ation, a pattern of O-substitution similar to those already discussed was present. [Pg.101]

Fig. 2.12.6. Identification of esterquat compounds FIA-APCI-MS-MS(+) (CID) product ion mass spectrum of selected [M — RCO]+ base peak ion of cationic surfactant blend of di-hydrogenated tallowethyl hydroxyethyl ammonium methane sulfate type (mlz 692 general formula (R(C0)0CH2CH2)2-N (CH3)-CH2CH2(0H)CH30S03) fragmentation behaviour under CID... Fig. 2.12.6. Identification of esterquat compounds FIA-APCI-MS-MS(+) (CID) product ion mass spectrum of selected [M — RCO]+ base peak ion of cationic surfactant blend of di-hydrogenated tallowethyl hydroxyethyl ammonium methane sulfate type (mlz 692 general formula (R(C0)0CH2CH2)2-N (CH3)-CH2CH2(0H)CH30S03) fragmentation behaviour under CID...
Fig. 16. ID COSY-NOESY experiment on the polysaccharide 6 [77]. The structure of a terminal 3,6-dideoxy-4-C-(l-hydroxyethyl)-D-xylohexose is shown in the inset. The COSY transfer is depicted using the solid line, while a dotted line is used for the NOESY transfer, (a) H spectrum of 6 at 600 MHz and 50°C. (b) ID COSY-NOESY spectrum acquired using the sequence of fig. 13(c) with the initial transfer of magnetization from H-8 and the following parameters = 100 ms, to = 29 ms, Tr = 32 ms, A = 0.5 ms, N = 0, 1,...,64,... Fig. 16. ID COSY-NOESY experiment on the polysaccharide 6 [77]. The structure of a terminal 3,6-dideoxy-4-C-(l-hydroxyethyl)-D-xylohexose is shown in the inset. The COSY transfer is depicted using the solid line, while a dotted line is used for the NOESY transfer, (a) H spectrum of 6 at 600 MHz and 50°C. (b) ID COSY-NOESY spectrum acquired using the sequence of fig. 13(c) with the initial transfer of magnetization from H-8 and the following parameters = 100 ms, to = 29 ms, Tr = 32 ms, A = 0.5 ms, N = 0, 1,...,64,...
Other P-lactam antibiotics have revolutionized our understanding of the structure-activity relationships in this large group of antibiotics. Thienamycin (9.53), discovered in 1976, is a broad-spectrum antibiotic of high activity. It is lactamase resistant because of its hydroxyethyl side chain but is not absorbed orally as it is highly polar. Unfortunately,... [Pg.568]

Melphalan has been determined spectrophotometrically at 262 nm in methanol solution [65]. The assay is linear in the 3 to 15 pg/ml range, with precision of 2%. In contrast with the above mentioned colorimetric methods, the procedure is not stability-indicating the major contaminant and degradation product, the bis(2-hydroxyethyl)derivative, has a UV spectrum very similar to that of Melphalan [48]. Ultraviolet spectro-photometric determinations in aqueous solution were also reported [66]. [Pg.284]

Carbapenems having a 6cr-hydroxyethyl side chain <2007BMC392> are both broad-spectrum antibiotics and competitive inhibitors (or poor substrates) of serine /3-lactamases. This particular side chain may play a role in the... [Pg.225]

A typical example is seen for 1-hydroxyethyl radical trapped in a y-irra-diated ethanol matrix at 77 K [16]. As is shown in Fig. 2, the cw ESR spectrum of the radical is composed of five lines due to hyperfine interactions with one a proton and three P protons of a methyl group. The hyperfine interaction depends on the location of the P protons with respect to the p. orbital of the unpaired electron. However, the observed hyperfine coupling constant is the same for all the p protons because of the quick rotation of the methyl group in the time scale of the cw ESR measurement. On the other hand, the ESE-detected ESR spectrum is composed of four lines due to the hyperfine interactions with... [Pg.12]

Figure 4. Solid state Si magic angle spinning NMR spectrum of (2-hydroxyethyl)trimethylammonium silicate. (Reproduced with permission from Ref. 26. Copyright 1988 The Chemical Society of Japan.)... Figure 4. Solid state Si magic angle spinning NMR spectrum of (2-hydroxyethyl)trimethylammonium silicate. (Reproduced with permission from Ref. 26. Copyright 1988 The Chemical Society of Japan.)...
Figure 5. Si NMR spectrum of the solution obtained by reheating the (2-hydroxyethyl)trimethylammonium silicate solid at ca. 50 °C. Figure 5. Si NMR spectrum of the solution obtained by reheating the (2-hydroxyethyl)trimethylammonium silicate solid at ca. 50 °C.
Whilst most attention focused upon the antibacterially active 6-(l-hydroxyethyl) penems (87), Osborne (SmithKline Beecham) found in 1981 that the dehydration of such penems Scheme 6.16) provided compounds which had only weak antibacterial activity, but good y5-lactamase inhibitory activity [86, 87]. Their spectrum ofj8-lactamase inhibitory activity is broader than that of clavulanic acid and they have greater potency than sulbactam. [Pg.331]

Hydroxyethyl functionalities can be anchored to poly(styrene-DVB) by reacting lithiated resin with ethylene oxide (15). A THF suspension of lithiated resin (2 g in 50 ml) was cooled to -80°C, and 15 ml of ethylene oxide at -80°C were added with a transfer pipet. The mixture was brought to room temperature (in about 3 hr) and the beads were separated by filtration, washed successively with THF H20 (3 1), 10% HC1, H2O, THF, and ether, and then vacuum dried at 70°C. The infrared spectrum showed an OH absorption. [Pg.20]


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See also in sourсe #XX -- [ Pg.91 , Pg.92 ]




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Hydroxyethylation

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