12. QUINONES: STRUCTURE AND DISTRIBUTION
675
of the natural product once more from putrefied fishmeal, revealed the
presence of two K 2 vitamins, Doisy's compound, m.p. 54°, and also the
lower isoprenolog, m.p. 50° (CXXXII; n = 6). These are now distinguished as vitamin K 2(3 5) and K 2(3 o), respectively.
Noll (184) has recently isolated a third crystalline vitamin of the K 2
series from Mycobacterium tuberculosis (Brevannes), the virulent human strain. This has been identified as vitamin K 2 ( 45) , m.p. 60-61°, by
comparison with synthetic material obtained by Isler and co-workers
(184a). [The same compound, 2-methyl-3-solanesyl-l,4-naphthoquinone
has also been synthesized by Folkers' group (89)]. Noll's vitamin is
virtually identical with the yellow oil obtained by Snow et al. (177)
from an unidentified strain of M. tuberculosis (and from M. phlei), and
also with the yellow oil isolated from M. phlei by Brodie, Davis, and
Fieser (185). According to Noll (186) the infrared spectrum of the
latter definitely assigns it to the K 2 series (not Κχ as originally suggested*). This material, according to Brodie et al, is remarkably active
in restoring oxidative phosphorylation in extracts of M. phlei deactivated
by irradiation.
The only other quinone relevant to this section is tetrahydroxybenzoquinone (CXXXV) which was first observed as a purple discoloration
on a sample of salted beans (187). Investigation revealed (188) that
the pigment is formed by Pseudomonas beijerincki Hof from myoinositol under rather special conditions (an alkaline medium contain
6-18% NaCl and low oxygen tension), the purple color being that of the
calcium (and perhaps also the magnesium) salt. (The corresponding
salts of rhodizonic acid may also be present.) This has recently been
confirmed by Weygand et al. (189) using labeled rat/o-inositol as substrate. In agar cultures, some of the pigment appears at a considerable
distance from the bacterial colonies, the characteristic distribution
strongly indicating that a colorless intermediate is formed initially by
the bacterium, which is subsequently autoxidized. Since Acetobacter
suboxydans Kluyver and de Leeuw can dehydrogenate rat/o-inositol to
a monoketone, Kluyver et al. (188) suggested that P. beijerincki might
similarly convert mt/o-inositol into a triketone (CXXXIII) which, in
alkaline solution, would enolize to hexahydroxybenzene (CXXXIV) and
then rapidly oxidize to tetrahydroxybenzoquinone (CXXXV). If this is
so, the steric requirements of P. beijerincki are less severe than those of
Acetobacter suboxydans which will dehydrogenate only axial hydroxyl
groups (190). The Dutch workers found that mt/o-inositol could be replaced by L-inositol, but not by quercitol, quebrachitol, pinitol, or quinic
acid, nor could P. beijerincki be replaced by other Pseudomonas spp.
* However, M. phlei produces more than one quinone (56).
675
of the natural product once more from putrefied fishmeal, revealed the
presence of two K 2 vitamins, Doisy's compound, m.p. 54°, and also the
lower isoprenolog, m.p. 50° (CXXXII; n = 6). These are now distinguished as vitamin K 2(3 5) and K 2(3 o), respectively.
Noll (184) has recently isolated a third crystalline vitamin of the K 2
series from Mycobacterium tuberculosis (Brevannes), the virulent human strain. This has been identified as vitamin K 2 ( 45) , m.p. 60-61°, by
comparison with synthetic material obtained by Isler and co-workers
(184a). [The same compound, 2-methyl-3-solanesyl-l,4-naphthoquinone
has also been synthesized by Folkers' group (89)]. Noll's vitamin is
virtually identical with the yellow oil obtained by Snow et al. (177)
from an unidentified strain of M. tuberculosis (and from M. phlei), and
also with the yellow oil isolated from M. phlei by Brodie, Davis, and
Fieser (185). According to Noll (186) the infrared spectrum of the
latter definitely assigns it to the K 2 series (not Κχ as originally suggested*). This material, according to Brodie et al, is remarkably active
in restoring oxidative phosphorylation in extracts of M. phlei deactivated
by irradiation.
The only other quinone relevant to this section is tetrahydroxybenzoquinone (CXXXV) which was first observed as a purple discoloration
on a sample of salted beans (187). Investigation revealed (188) that
the pigment is formed by Pseudomonas beijerincki Hof from myoinositol under rather special conditions (an alkaline medium contain
6-18% NaCl and low oxygen tension), the purple color being that of the
calcium (and perhaps also the magnesium) salt. (The corresponding
salts of rhodizonic acid may also be present.) This has recently been
confirmed by Weygand et al. (189) using labeled rat/o-inositol as substrate. In agar cultures, some of the pigment appears at a considerable
distance from the bacterial colonies, the characteristic distribution
strongly indicating that a colorless intermediate is formed initially by
the bacterium, which is subsequently autoxidized. Since Acetobacter
suboxydans Kluyver and de Leeuw can dehydrogenate rat/o-inositol to
a monoketone, Kluyver et al. (188) suggested that P. beijerincki might
similarly convert mt/o-inositol into a triketone (CXXXIII) which, in
alkaline solution, would enolize to hexahydroxybenzene (CXXXIV) and
then rapidly oxidize to tetrahydroxybenzoquinone (CXXXV). If this is
so, the steric requirements of P. beijerincki are less severe than those of
Acetobacter suboxydans which will dehydrogenate only axial hydroxyl
groups (190). The Dutch workers found that mt/o-inositol could be replaced by L-inositol, but not by quercitol, quebrachitol, pinitol, or quinic
acid, nor could P. beijerincki be replaced by other Pseudomonas spp.
* However, M. phlei produces more than one quinone (56).