A simple method for the analysis of nereistoxin and its metabolites in human serum using headspace solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) is developed. A vial containing a serum sample, 5M sodium hydroxide, and benzylacetone (internal standard) is heated to 70°C, and an SPME fiber is exposed for 30 min in the headspace of the vial. The compounds extracted by the fiber are desorbed by exposing the fiber in the injection port of the GC-MS. The calibration curves show linearity in the range of 0.05–5.0 µg/mL for nereistoxin and N-methyl-N-(2-methylthio-1-methylthiomethyl)ethylamine, 0.01–5.0 µg/mL for S,S′-dimethyl dihydronereistoxin, and 0.5–10 µg/mL for 2-methylthio-1 -methylthiomethylethylamine in serum. No interferences are found, and the analysis time is 50 min for one sample. In addition, this proposed method is applied to a patient who attempted suicide by ingesting Padan 4^R, a herbicide. Padan 4^R contains 4% cartap hydrochloride, which is an analogue of nereistoxin. Nereistoxin and its metabolites are detected in the serum samples collected from the patient during hospitalization. The concentration ranges of nereistoxin in the serum are 0.09–2.69 µg/mL.

Berberine, a fluorescent, aromatic, heterocyclic alkaloid, produced in a diversity of plants, was found to have curative properties in Chinese herbal medicine. Berberine is used as a treatment for gastric and inflammatory diseases and as an antimicrobial agent. More recently the potential of this alkaloid in diverse new medical application like cardiology, neurology and oncology is being investigated. As a result of its fluorescent properties, it has also been used in chemistry to study protein conformation and protein/protein interactions and to quantitate non-fluorescent compounds. All these applications will be summarized and discussed in this review.