Subject: Sperm Whale:biochemical composition of spermaceti (fwd)

Mike Williamson (pita@www1.wheelock.edu)
Mon, 14 Jun 1999 21:07:02 -0400 (EDT)

To: MARMAM@UVVM.UVIC.CA
Subject: biochemical composition of spermaceti (fwd)

From: "h-kimura" <hkimura0@silver.ocn.ne.jp>

"Detailed Composition of Oil in a Head of a Sperm Whale"

  What is a detailed content and alkyl balance of free fatty alcohols and
free fatty acids which are not consumed for the biosynthesis of spermaceti
as a main storage liquid ester waxes, especially cetylpalmytate,
in a head of a sperm whale like ?
  Because the coexistence of the two materials, free fatty alcohols and
fatty acids with cetylpalmytate is one of the important factors influencing
the physical properties of spermaceti.
  Biosynthesis of the ester waxes such as spermaceti or Jojoba oil are
reported(1-3).
  In the biosynthesis of the ester waxes, free fatty alcohols as one of the
components of ester waxes are required and they must be produced.
  On this matter, it is reported that biosynthesis of the free fatty
alcohols are proceeded with action of acyl reductase, by the stepwise
reduction of very long chain fatty acids(VLCFA) with a chain length of
C30-C34(1,3).  On the other hand, fatty acyl-CoAs are the sourse for fatty
acids as another starting materials for biosynthesis of ester waxes.
  The main ester wax of spermaceti is cetylpalmytate, which is formed from
cetyl alcohol and palmitic acid.
  However, in the synthetic pathway abovefor the fatty alcohols, VLCFAs with
a chain length of C30-C34 are the main source for the biosynthesis of fatty
alcohols.  in this case, needed cetyl alcohol for the spermaceti is not
synthesized biochemically.
  Therefore, from the stand point of organic reactions, fatty alcohols,
formed in the pathway above, with a chain length of C30-C34 cannot be a
source for cetyl alcohol, and thus, VLCFAs must be decomposed into the
shorter length units, especially palmitic acid(C16) for the biosynthesis of
cetyl alcohol as one of the components for spermaceti.
  A detailed biosynthetic mechanism, from VLCFAs, for the biosynthesis of
the free fatty alcohols with a chain length of C10, C12, C14, C16, C18 or so
is required because the coexistence of these free fatty alcohols as well as
free fatty acids with ester waxes is one of the important factors
influencing the physical properties of the ester waxes such as spermaceti
and Jojoba oil.

Hiroshi Kimura
hkimura0@silver.ocn.ne.jp

references
1. T.R.Slabas, Biochemist, Feb., 11(1997).
2. K.Kayama, INFORM, 9(9), 886(1997).
3. H.M.davies, Proceedings for "Engineering New Oilseed Crops from
raprseed", in a homepage,
   www.hort.purdue.edu/newcrop/proceedings1996/v3-299.html



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