Pictet-Spenglerases (P-Sases) catalyze the Pictet-Spengler (P-S) reactions and exhibit high stereoselectivity and regioselectivity under mild conditions. The typical P-S reaction refers to the condensation and recyclization of β-arylethylamine with aldehyde or ketone under acidic conditions to form tetrahydroisoquinoline and β-carboline alkaloid derivatives. The related enzymatic products of P-Sases are the backbones of various bioactive compounds, including clinical drugs: morphine, noscapine, quinine, berberine, ajmaline, morphine. Furthermore, the activity of P-Sases in stereoselective and regioselective catalysis is also valuable for chemoenzymatic synthesis. Therefore, this review summarizes the research progress in the discovery, functional identification, biological characteristics and catalytic applications of P-Sases, which provide the useful theoretical reference in future P-Sases research and development.
Alkaloids/chemistry* ; Catalysis ; Enzymes/metabolism* ; Research/trends* ; Tetrahydroisoquinolines/chemistry*

OBJECTIVE To systematically review the background of bioequivalence assessment of nasal sprays and nasal aerosols and the guiding considerations for the bioequivalence assessment of these complex drug-device combination products by regulatory authorities in the United States, the European Union(EU) and China. METHODS This article provided detailed explanations on the innovative weight of evidence assessment approach adopted by the US Food and Drug Administration(FDA), and the statistical rationale, methods and considerations for the bioequivalence assessment of nasal sprays and nasal aerosols. Using the calculation methods described in the draft guidance for budesonide inhalation suspension and the draft guidance for fluticasone nasal spray propionate issued by FDA, the statistical parameters of two-sided and one-sided population bioequivalence calculation were realized through R language programming, and pseudo-code for the population bioequivalence (PBE) calculation programs was provided. This article also presented a comprehensive review of published guidelines and summaries review principles of the EU and China for nasal sprays and nasal aerosols equivalence assessment. RESULTS & CONCLUSION Nasal sprays/nasal aerosols is the focus of innovative and generic drug development in recent years. This paper provided valuable considerations references for the research and development, quality control and bioequivalence evaluation of generic preparations of nasal sprays/nasal aerosols.