xanthene <--> listnames

[ttweed@wildrockies.org (Tony Tweedale)]

  after reading janet raloff's latest in _science news_ i got curious on the
  structure of xanthene, which chlorine substituted compound the article said
  has been found in P&P effluent but had problems being differentiated in
  elution from pcdd/f.  i was thinking it was a one ring compound, perhaps
  because i knew it is a biological molecule, but in fact it is C(13)H(10)O,
  m.w. 188.22.  my regular dictionary said it's found in urine ('xanth-' =
  yellow in greek).
  
         0
  / \ /\ / \
  |     |    |     |
  \ / \ /\ /     (messy! assume 2 aromatic rings & a bridge inbetween--not
  three rings)
  
  
  so, substitute an oxygen for the bottom C in the bridge to get a dioxin, or
  eliminate it and get a furan.  the point raloff was implying (by also
  giving an example of a common brominated analog to tcdd w/ greater
  toxicity), and that i want to make, is: 1) there are hundreds Ah binding
  analogs and other substitutes for chlorinated Ah binding pcdd/f/pcb's.  2)
  there are other receptors thousands of other persistant & bioaccum.
  molecules can bind to, many non-chlorinated and non-halogenated.  i believe
  sulfur substituted analogs to pcdd/f are of some concern, for example.
  
  so, 3) i propose a merger of wash. toxics coaltn's endohealth list,
  sierra's consequence-env.-hormones list and cchw's dioxin-l.  sierra has
  the more descriptive name and larger traffic than wtc's,  but cchw was
  there first and seems to be the largest (as a result of age?). anyway, this
  may be a non-starter for any number of reasons, but i think one major
  synnergy would be that more concerned parties could be put in touch w/ more
  posted information, by merging subscribers.  smaller advantages include not
  missing information, easier posting of information.
  
  
  tony tweedale