Anions rather than cations: While resorcinarenes bind cations through cation–π interactions, methylene‐bridged cavitands surprisingly bind anions through CH⋅⋅⋅anion interactions with the acetal protons at the wider rim (see model of the complex in the scheme). Mass spectrometry, in agreement with theory, provides evidence for anion binding on the concave side of the cavitand bowl.

A robust, quantitative ultraperformance liquid chromatography ion trap multistage scanning mass spectrometric (UPLC/MS3) method was established to characterize and measure five deoxyguanosine (dG) adducts formed by reaction of the chemotherapeutic nitrogen mustard (NM) bis-(2-chloroethyl)ethylamine with calf thymus (CT) DNA. In addition to the known N7-guanine (NM-G) adduct and its crosslink (G-NM-G), the ring-opened formamidopyrimidine (FapyG) mono-adduct (NM-FapyG) and cross-links in which one (FapyG-NM-G) or both (FapyG-NM-FapyG) guanines underwent ring-opening to FapyG units were identified. Authentic standards of all adducts were synthesized and characterized by NMR and mass spectrometry. These adducts were quantified in CT DNA treated with NM (1 μM) as their deglycosylated bases. A two-stage neutral thermal hydrolysis was developed to mitigate the artifactual formation of ring-opened FapyG adducts involving hydrolysis of the cationic adduct at 37 °C, followed by hydrolysis of the FapyG adducts at 95 °C. The limit of quantification values ranged between 0.3 and 1.6 adducts per 107 DNA bases, when the equivalent of 5 μg DNA hydrolysate was assayed on column. The principal adduct formed was the G-NM-G cross-link, followed by the NM-G mono-adduct; the FapyG-NM-FapyG adduct was at the limit of detection. The NM-FapyG adducts formed in CT DNA at a level of ~20% that of the NM-G adduct. NM-FapyG has not been previously quanitified and the FapyG-NM-G and FapyG-NM-FapyG adducts have not be previously characterized. Our validated analytical method was then applied to measure DNA adduct formation in the MDA-MB-231 mammary tumor cell line exposed to NM (100 μM) for 24 h. The major adduct formed was NM-G (970 adducts per 107 bases), followed by G-NM-G (240 adducts per 107 bases) and NM-FapyG (180 adducts per 107 bases), and lastly the FapyG-NM-G cross-link adduct (6.0 adducts per 107 bases). These lesions are expected to contribute to the NM-mediated toxicity and genotoxicity in vivo.

Several important neurotransmitter precursors were hyperpolarized via homogeneous hydrogenation with parahydrogen. Polarization enhancement was achieved for (1)H and (13)C spins by several orders of magnitude compared to thermal spectra. Such large signal enhancements of these molecules could facilitate neurotransmitter studies.

A system that provides a sustained hyperpolarized (1)H NMR signal in an aqueous medium is reported. The enhanced signal lasts much longer than typical (1)H T(1) values, uncovering new possibilities for implementing hyperpolarized (1)H NMR/MRI experiments or performing kinetics studies that would not otherwise be detectable.

Due to the importance of Mn2+ ions in biological processes, it is of growing interest to develop protocols for analysis of Mn2+ uptake and distribution in cells. A supramolecular metal displacement assay can provide ratiometric fluorescence detection of Mn2+, allowing for quantitative and longitudinal analysis of Mn2+ uptake in living cells.