Binary code, a flexible tool for diagnostic metabolite sequencing of medicinal plants.

The principle of chromatographic fingerprint is that certain diagnostic metabolites should be always distributed in a given plant and currently, it has been widely accepted as a promising means for medicinal plant authentication. Moreover, the chemical profile is the only evidence to clarify the ingredients of those consumable plant products, e.g. traditional Chinese medicine (TCM) prescriptions. Herein, efforts were made to describe the diagnostic metabolome of medicinal plant or TCM prescription using a binary code sequence. Forty-five well-known medicinal plants along with six relevant prescriptions were employed for concept illustration and proof. Each plant was subjected to chemical characterization, and diagnostic metabolites of all plants were gathered into a chemical pool containing 595 compounds. A robust method enabling the detection of all 595 constituents was then developed using LC coupled to scheduled multiple reaction monitoring. Analyst™ software was responsible for automatically judging the presence (defined as "1") or absence (defined as "0") of each analyte with a defined signal-to-noise threshold (S/N > 100). After converting each medicinal plant to a binary sequence consisting of 595 codes, an in-house database was built by involving all sequences. The potentials of sequence library retrieval towards plant authentication, preliminary chemical characterization, and deformulation of TCM prescriptions were demonstrated after that the diagnostic metabolome of each test sample was translated to a binary code sequence. Above all, binary code is a flexible tool for diagnostic metabolite sequencing of medicinal plants, and it should be an alternative tool of DNA barcoding towards plant authentication.

Spatial and temporal distribution and risk assessment of polycyclic aromatic hydrocarbons in surface seawater from the Haikou Bay, China.

Spatial and temporal distributions of 14 polycyclic aromatic hydrocarbons (PAHs) were investigated in surface waters of Haikou Bay, China from October 2013 to September 2014. The total PAHs concentrations ranged from 420.2 to 2539.1 ng L(-1) with the average value of 1016.3±455.8 ng L(-1), which were predominated by low molecular weight PAHs (2- and 3-ring PAHs). Moreover, PAHs displayed spatial and temporal variations in the concentration and composition pattern. Source analysis based on isomer ratios indicated that the PAHs mostly originated from petroleum and combustion processes. An eco-toxicological risk assessment showed that the potential risk of individual PAHs had reached moderate to high levels and the total concentrations of PAHs had also reached a relatively high level compared with previous studies. This study offers important information on the pollution levels of 14 PAHs in the surface waters of Haikou Bay and recommends that prevention and control of PAHs pollution should be implemented in the region.