Within the framework of our continuous efforts to explore Hypericum species from Jordan, we report the analysis of the major active metabolites, naphthodianthrones and phloroglucinols, in the methanolic extracts of two under-explored Hypericum species; H. empetrifolium Willd. and H. sinaicum Hochst. & Steud. ex Boiss., using LC-(+,-)-ESI-MS (TIC and SIM) and LC-UV/Vis spectroscopy. Based on the...

With 2-D gel mapping, it is often observed that essentially identical proteins migrate to different positions in the gel, while some seemingly well-resolved protein spots consist of multiple proteins. These observations can undermine the validity of gel-based comparative proteomic studies. Through a comparison of protein identifications using direct MALDI-TOF/TOF and LC-ESI-MS/MS analyses of 2-...

BACKGROUND The alcohol biomarker phosphatidylethanol (PEth) comprises a group of ethanol-derived phospholipids formed from phosphatidylcholine by phospholipase D. The PEth molecular species have a common phosphoethanol head group onto which 2 fatty acid moieties are attached. We developed an electrospray ionization (ESI) LC-MS method for qualitative and quantitative measurement of different PEt...

A sensitive and ultra-fast method utilizing the laser diode thermal desorption ion source using atmospheric pressure chemical ionization coupled to tandem mass spectrometry (LDTD-APCI-MS/MS) was developed for the quantitative analysis of BKM120, an investigational anticancer drug in human plasma. Samples originating from protein precipitation (PP) followed by salting-out assisted liquid-liquid ...

The applicability of GC, GC/MS and liquid chromatography with tandem mass spectrometry (LC/MS/MS) to screening for 140 pesticides in agricultural products was examined. Validation of multi-residue screening methods for the determination of 88 pesticides in 12 crops (asparagus, cauliflower, burdock, carrot, broccoli, spinach, matsutake mushroom, orange, soybean, sesame, millet and tea) was done ...

Objective: Ipomoea mauritiana is used in both Ayurveda and folk medicine systems. The tuberous roots are known to be diuretic, depurative, carminative, and anthelmintic. The objective of the current study was to identify phenolic antioxidants from I. mauritiana using spectrophotometric and LC-MS analysis. Materials and Methods: An activity-guided fractionation and purification process was used t...

Cortisol is an important diagnostic marker for the production of steroid hormones, and accurate measurements of serum cortisol are necessary for proper diagnosis of adrenal function. A candidate reference method involving isotope dilution coupled with liquid chromatography/mass spectrometry (LC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS) has been developed and critically e...

A simple, rapid, and sensitive on-line liquid chromatographic electrochemistry/electrospray/tandem mass spectrometry (LC-EC/ESI-MS/MS) method for the determination of zotepine in human serum was developed using a new generated-electrochemically fragment ion, and was validated. A recent novel technique of LC-EC/ESI-MS/MS that combines LC-MS/MS and the on-line EC reaction is potentially applicabl...

Four new dicaffeoylquinic acid derivatives and two known 3-caffeoylquinic acid derivatives were isolated from methanol extracts using the aerial parts of Salicornia herbacea. The four new dicaffeoylquinic acid derivatives were established as 3-caffeoyl-5-dihydrocaffeoylquinic acid, 3-caffeoyl-5-dihydrocaffeoylquinic acid methyl ester, 3-caffeoyl-4-dihydrocaffeoylquinic acid methyl ester, and 3,...