摘要： In the comparison with SARS-CoV of 2003, SARS-CoV-2 is extremely well adapted to the human populations and its adaptive shift from the animal host to humans must have been even more extensive. By the blind watchmaker argument, such an adaptive shift can only happen prior to the onset of the current pandemic and with the aid of step-by-step selection. In this view, SARS-CoV-2 could not have possibly evolved in an animal market in a big city and even less likely in a laboratory. Discussions of the origin of SARS-CoV-2 need to factor in the long process of adaptive shift and some models have indeed advanced in that direction.
摘要：Using 4΄-methoxy-5-hydroxyisoflavone and 4΄,5-dihydroxy-7-methoxyisoflavone as leding compounds, 6-methoxy-2H-phenanthro[9,10-c]pyrazol-11-ol (1a) and 9-methoxy-2H-phenanthro [9,10-c]pyrazol-6,11-diol (1b) were synthesized by two dehydration processes in the EtOH solution. They were characterized by IR, 1H NMR and 13C NMR. The black prism crystal of 1a was grown by the slow solvent evaporation technique from 40:1 (v/v) CHCl3/MeOH, and it was determined by single-crystal X-ray diffraction. In the crystal structure, 1a was stabilized by intramolecular (O–H···N) and intermolecular (N–H···O, O–H···O, π···π, C–H···π) interactions. In addition, the fluorescence properties of 1a and 1b in the base and neutral media revealed that they possessed excited state intramolecular proton transfer phenomena (ESIPT).