1H and13C NMR data to aid the identification and quantification of residual solvents by NMR spectroscopy

The essential oil of Stachys riederi var. japonica (Family: Lamiaceae) was extracted by hydrodistillation and determined by GC and GC-MS. A total of 40 components were identified, representing 96.01% of the total oil composition. The major compounds in the essential oil were acetanisole (15.43%), anisole (9.43%), 1,8-cineole (8.07%), geraniol (7.89%), eugenol (4.54%), caryophyllene oxide (4.47%), caryophyllene (4.21%) and linalool (4.07%). Five active constituents (acetanisole, anisole, 1,8-cineole, eugenol and geraniol) were identified by bioactivity-directed fractionation. The essential oil possessed fumigant toxicity against maize weevils (Sitophilus zeamais) and booklice (Liposcelis bostrychophila), with LC50 values of 15.0 mg/L and 0.7 mg/L, respectively. Eugenol and anisole exhibited stronger fumigant toxicity than the oil against booklice. 1,8-Cineole showed stronger toxicity, and anisole as well as eugenol exhibited the same level of fumigant toxicity as the essential oil against maize weevils. The essential oil also exhibited contact toxicity against S. zeamais adults and L. bostrychophila, with LC50 values of 21.8 µg/adult and 287.0 µg/cm2, respectively. The results indicated that the essential oil of S. riederi var. japonica and its isolates show potential as fumigants, and for their contact toxicity against grain storage insects.

show abstract

“…MS m / z (%): 150 (30), 135 (100), 107 (20), 92 (24), 77 (38), 64 (18), 43(15). The spectral data matched with the previous reports [ 23 , 24 ].…”

Section: Resultssupporting

confidence: 88%

Identification of Insecticidal Constituents from the Essential Oil from the Aerial Parts Stachys riederi var. japonica

Quan

Liu

2018

Molecules

View full text Add to dashboard Cite

show abstract

“…1 H chemical shifts in DMSO can differ by up to 5 ppm from the corresponding shifts in CDCl 3 and therefore, the calculations for CDCl 3 cannot be used with confidence to predict chemical shifts in DMSO. Few detailed studies of the effects of DMSO on 1 H chemical shifts have been carried out. Gottlieb et al 15 gave the 1 H (and 13 C) chemical shifts of 36 common impurities in seven common solvents and, more recently, Jones et al 16 recorded similar data for 60 common solvents in CDCl 3 , DMSO, D 2 O and CD 3 OD. GlaxoWellcome 17a and Pfizer 17b have produced pamphlets with the 1 H shifts of ca 50 common compounds in the same four solvents.…”

Section: S Shielding Nomenclature ( ))mentioning

confidence: 76%

¹H chemical shifts in NMR: Part 23, the effect of dimethyl sulphoxide versus chloroform solvent on ¹H chemical shifts

Abraham

Byrne

Griffiths

et al. 2006

Magnetic Reson in Chemistry

114

128

View full text Add to dashboard Cite

The 1H chemical shifts of 124 compounds containing a variety of functional groups have been recorded in CDCl3 and DMSO-d6 (henceforth DMSO) solvents. The 1H solvent shift Delta delta = delta(DMSO) - delta(CDCl3) varies from -0.3 to +4.6 ppm. This solvent shift can be accurately predicted (rms error 0.05 ppm) using the charge model of alpha, beta, gamma and long-range contributions. The labile protons of alcohols, acids, amines and amides give both, the largest solvent shifts and the largest errors. The contributions for the various groups are tabulated and it is shown that for H.C.C.X gamma-effects (X = OH, NH, =O, NH.CO) there is a dihedral angle dependence of the gamma-effect. The group contributions are discussed in terms of the possible solvent-solute interactions. For protic hydrogens, hydrogen bonding is the dominant interaction, but for the remaining protons solvent anisotropy and electric field effects appear to be the major factors.

show abstract

“…Integrated peaks of parent were compared with those of the standard. The integrals of interest used in the purity calculation were the CH at 8.06 ppm on the methyl imidazole ring for the MDZG and one of the protons at 5.2 ppm from the CH 2 and used to give a purity figure of the sample using [16]:…”

mentioning

confidence: 99%

In vitro and in vivo glucuronidation of midazolam in humans

Hyland¹,

Osborne²,

Payne³

et al. 2009

Brit J Clinical Pharma

View full text Add to dashboard Cite

Keywords 1′-hydroxymidazolam, 4-hydroxymidazolam, glucuronidation, in vitro metabolism, in vivo metabolism, midazolam ---------------------------------------------------------------------- Received WHAT THIS STUDY ADDS• N-glucuronide of midazolam has been quantified in human urine, indicating for the first time that this route of metabolism occurs in vivo.• Metabolism of 4-hydroxymidazolam has been compared with that of 1′-hydroxymidazolam in vitro.• This study provides further evidence, in vitro and in vivo, of the importance of N-glucuronidation in the metabolism of midazolam and its metabolites. AIMSMidazolam (MDZ) is a benzodiazepine used as a CYP3A4 probe in clinical and in vitro studies. A glucuronide metabolite of MDZ has been identified in vitro in human liver microsome (HLM) incubations. The primary aim of this study was to understand the in vivo relevance of this pathway. METHODSAn authentic standard of N-glucuronide was generated from microsomal incubations and isolated using solid-phase extraction. The structure was confirmed using proton nuclear magnetic resonance (NMR) and RESULTSNMR data confirmed conjugation of midazolam N-glucuronide (MDZG) standard to be on the a-nitrogen of the imidazole ring. In vivo, MDZG in the urine accounted for 1-2% of the administered dose. In vitro incubations confirmed UGT1A4 as the enzyme of interest. The pathway exhibited atypical kinetics and a substrate inhibitory cooperative binding model was applied to determine Km (46 mM, 64 mM), Vmax (445 pmol min -1 mg -1, 427 pmol min -1 mg -1) and Ki (58 mM, 79 mM) in HLM and rUGT1A4, respectively. From incubations with HLM and rUGT enzymes, N-glucuronidation of 1′-OH MDZ and 4-OH MDZ is also inferred. CONCLUSIONSA more complete picture of MDZ metabolism and the enzymes involved has been elucidated. Direct N-glucuronidation of MDZ occurs in vivo. Pharmacokinetic modelling using Simcyp™ illustrates an increased role for UGT1A4 under CYP3A inhibited conditions.

show abstract

1H and13C NMR data to aid the identification and quantification of residual solvents by NMR spectroscopy

Abstract: We present reference data and a javascript web page which allow the rapid identification and quantification of residual solvents by NMR. The data encompass all of the ICH-prescribed solvents and were obtained for a number of NMR solvents. We also present an example of its application.

Cited by 47 publications

References 2 publications

Identification of Insecticidal Constituents from the Essential Oil from the Aerial Parts Stachys riederi var. japonica

Identification of Insecticidal Constituents from the Essential Oil from the Aerial Parts Stachys riederi var. japonica

¹H chemical shifts in NMR: Part 23, the effect of dimethyl sulphoxide versus chloroform solvent on ¹H chemical shifts

In vitro and in vivo glucuronidation of midazolam in humans

Contact Info

Product

Resources

About

1H and13C NMR data to aid the identification and quantification of residual solvents by NMR spectroscopy

Abstract: We present reference data and a javascript web page which allow the rapid identification and quantification of residual solvents by NMR. The data encompass all of the ICH-prescribed solvents and were obtained for a number of NMR solvents. We also present an example of its application.

Cited by 47 publications

References 2 publications

Identification of Insecticidal Constituents from the Essential Oil from the Aerial Parts Stachys riederi var. japonica

Identification of Insecticidal Constituents from the Essential Oil from the Aerial Parts Stachys riederi var. japonica

1H chemical shifts in NMR: Part 23, the effect of dimethyl sulphoxide versus chloroform solvent on 1H chemical shifts

In vitro and in vivo glucuronidation of midazolam in humans

Contact Info

Product

Resources

About

¹H chemical shifts in NMR: Part 23, the effect of dimethyl sulphoxide versus chloroform solvent on ¹H chemical shifts