Proton signal assignments

Proton signal assignments (Fig. 6.2), corresponding chemical shifts and estimated homonuclear J-coupling constants for all 3 carbohydrate monomers... 

Fig. 7.4. Schematic structure of the active site of Cu2Zn2-superoxide dismutase. The labels refer to the proton signal assignment for the Cu2Co2 derivative reported in Table 7.3 [15,16].

The spectra of polyglucuronic acid grafted amines were analyzed and the different proton signals assigned by 2D-COSY (spectrum not presented) and 2D HMQC... 

The umbelliferone ether structure 1 was suggested for a natural product which was isolated from galbanum resin Does this structure fit the NMR results 48 Is it possible to give a complete spectral assignment despite lack of resolution of the proton signals at 200 MHz What statements can be made about the relative configuration ... 

Proton signals are assigned in B by means of the CH connectivities which can be read off from the CH COSY plot. Additionally, an OH group can be identified by the fact that there is no correlation for the broad signal at = 4.33 in the CH COSY plot. Connection of the OH group (<5// =4.33)... 

Carbon atoms and protons are assigned by means of the proton-carbon connectivities as identified in the HC HSQC and HMBC experiment (b and c). The latter also permits the derivation of the connection of the ethyl groups to the porphyrin ring. The cross signals in the relevant part a of the HH COSY plot (a) are used to connect the methyl and methylene subunits to the ethyl groups. 

The sample prepared is not particularly pure, so instead of the 30 signals expected, 33 signals are observed in the // broadband decoupled C NMR spectrum. Only by pooling information from the DEPT experiment and from the reliable analysis be obtained, as shown in Table 51.1. Here the AB systems of the geminal CH2 protons are assigned. 

On the other hand, the NMR spectrum (Figure 6) of kasuganobiosa-mine (4) shows that the anomeric proton signal is located at 5.02 p.p.m., therefore the configuration of the proton is assigned to the equatorial configuration or the same ground (17,27). 

Applications Albert et al. [455] have shown continuous-flow SFC-NMR spectra of five plasticisers (DEP, DNPP, DPP, BBP, DNBP). On-flow and stopped-flow pSFC-NMR of synthetic mixtures of phthalates were reported [457]. The feasibility of SFC-NMR coupling has been demonstrated with real-life applications [458]. Figure 7.20 shows a reconstruction of an extraction profile from a PVC tube [152]. The profiles of the integral aromatic proton signals between 7.2 and 8.2 ppm and the ester protons at 4.42 ppm display the relative concentration of the extracted phthalate as a function of the proceeding extraction. The structure of the extracted phthalate could be assigned to DEHP (Figure 7.21). 

Fig. 1 Proton spectrum of compound 1 at 200 MHz. Signal assignment (from left to right) OH proton (singlet), aromatic protons (singlet), methine proton (doublet), OCH2 protons (apparently a quintet), CH3 protons, triplet. The small signal at 7.24 ppm is due to CHC13...

Because of the symmetric structure, H NMR spectra of 12 show only two signals assignable to methyl and phenyl protons at S 0.50... 

Assign as many proton signals as possible with respect to each of the (R)-and (iS )-MTPA esters. 

---