{1498} revision 0 modified: 01-22-2020 20:06 gmt

Optimization and functionalization of red-shifted rhodamine dyes

  • Zwitterion form is fluorescent and colored; lactone form is not and colorless.
  • Lactone form is lipophyllic; some mix seems more bioavailable and also results in fluorogenic dyes.
  • Good many experiments with either putting fluorine on the azetidines or on the benzyl ring.
  • Fluorine on the azetidine pushes the K ZLK_{Z-L} toward lactone form; fluorine on the benzyl ring pushes it toward the zwitterion.
  • Si-rhodamine and P-rhodamine adopt the lactone form, and adding appropriate fluorines can make them fluorescent again. Which makes for good red-shifted dyes, ala JF669
  • N-CH3 can be substituted in the oxygen position too, resulting in blue-shifted dye which is a good stand-in for EGFP.