The preceding volume appeared in 1987 and covered the literature up to
the end of 1984. The present work extends the coverage to the end of
1994 with a sprinkling of references to 1995 papers. Nearly 900 new qui
nones are described, including one or two which were overlooked
previously, together with new work on older compounds. For each new
quinone information is provided on the distribution, spectra, structure
and chemistry, and on biosynthesis where available. Sadly, there is very
little new chemistry, as structures are now elucidated almost entirely
by spectroscopic methods and X-ray analysis. As always I am grateful to
many colleagues who sent me papers and other information in advance of
publication. 1972 and 1987 volumes are referred to as NOQ II and NOQ
III, The respectively. In the spectroscopic data the notation (?)
indicates that informa- tion is missing or is dubious. R.H.T. Aberdeen,
November 1995 1 Benzoquinones 1 New sources of p-benzoquinone are the
cephalic glands of Eucera bees and 2 Arthrobacter bacteria and it is
part ofthe defensive secretion ofthe caterpillar 3 Romalea guttata.
However, the natural occurrence of o-benzoquinone has not been reported
and is unlikely. Simple monosubstituted o-benzoquinones occur 4 only as
transient metabolic intermediates. It has been shown that in the leaves
of X anthium occidentale (Compositae) chlorogenic acid is in equilibrium
with a small amount of the corresponding o-quinone but the latter has
not been isolated.
