170
5. Nonaromatic Compounds
reactions and therefore a possibility for the generation of compounds of
intrinsic chemical or biological interest.
Not all hydrocarbons that are isolated from marine organisms need necessarily be derived via biosynthesis. The possibility of isolating substances of
extraneous origin that have resulted from spillage or dumping of oil or from
other man-made pollutants have become increasingly apparent in recent
years. Boylan and Tripp (1971) have demonstrated that a considerable range
of hydrocarbons, notably benzene and naphthalene derivatives, are extractable into sea water from crude oil or kerosene. No doubt these compounds
find their way into the marine biosphere and are being accumulated by some
organisms.
Because of a traditional association of hydrocarbons with petroleum
products, one would expect the concentration of hydrocarbons in plants or
animals to be rather low. Although this is generally true some notable
exceptions have been reported in the literature. Perhaps the most extreme
concentration of a hydrocarbon (albeit an isoprenoid one) in a marine source
has been found by Heller et al. (1957). In a survey of the liver oils of eighteen
species of sharks these workers showed that sixteen species contained less
than one percent of squalene (C 3 oH 5 o), while the liver oil of the shark
Dalatias licha consisted of 70%, and the liver oil of the shark Centrophorus
uyata of no less than 90% squalene. Doubtless more typical is the investigation by Lambertsen and Holman (1963) of the hydrocarbon content and
composition of herring oil. This oil contained 0.05% of a mixture of hydrocarbons ranging from C i4 to C 33 , with odd-numbered compounds predominating, in addition to a number of isoprenoid hydrocarbons. Predominance of odd-numbered compounds is a biogenetic indicator for their
origin from even-numbered fatty acids.
As is true for fatty acid research, much of the work on hydrocarbon
constituents of marine organisms has been primarily undertaken with an
aim other than structural chemical, in this case often geochemical or phylogenetic. Some examples of recent research include the hydrocarbon composition of some blue-green algae, including several marine species (Winters et
ai, 1969) and the most extensive survey to-date of twenty-four species of
green, red, and brown marine algae (Youngblood et ai, 1971). These workers
identified several new hydrocarbons, a C 16 compound containing a cyclopropane group (tentatively) from the green algae Ulva lactuca and Enteromorpha compressa and a number of Ci 7 , C 19 , and C 2i mono to hexaolefins,
none conjugated. The authors (Youngblood et ah, 1971) made the interesting
observation that in one alga, Ascophyllum nodosum the polyunsaturated
hydrocarbons occurred exclusively in the reproductive tissue of the plant.
The C 2 i hexaene, all c/s-3,6,8,12,15,18-heneicosahexaene, has also tentatively been identified by Lee et al. (1970) from the marine diatom Skeletonema
5. Nonaromatic Compounds
reactions and therefore a possibility for the generation of compounds of
intrinsic chemical or biological interest.
Not all hydrocarbons that are isolated from marine organisms need necessarily be derived via biosynthesis. The possibility of isolating substances of
extraneous origin that have resulted from spillage or dumping of oil or from
other man-made pollutants have become increasingly apparent in recent
years. Boylan and Tripp (1971) have demonstrated that a considerable range
of hydrocarbons, notably benzene and naphthalene derivatives, are extractable into sea water from crude oil or kerosene. No doubt these compounds
find their way into the marine biosphere and are being accumulated by some
organisms.
Because of a traditional association of hydrocarbons with petroleum
products, one would expect the concentration of hydrocarbons in plants or
animals to be rather low. Although this is generally true some notable
exceptions have been reported in the literature. Perhaps the most extreme
concentration of a hydrocarbon (albeit an isoprenoid one) in a marine source
has been found by Heller et al. (1957). In a survey of the liver oils of eighteen
species of sharks these workers showed that sixteen species contained less
than one percent of squalene (C 3 oH 5 o), while the liver oil of the shark
Dalatias licha consisted of 70%, and the liver oil of the shark Centrophorus
uyata of no less than 90% squalene. Doubtless more typical is the investigation by Lambertsen and Holman (1963) of the hydrocarbon content and
composition of herring oil. This oil contained 0.05% of a mixture of hydrocarbons ranging from C i4 to C 33 , with odd-numbered compounds predominating, in addition to a number of isoprenoid hydrocarbons. Predominance of odd-numbered compounds is a biogenetic indicator for their
origin from even-numbered fatty acids.
As is true for fatty acid research, much of the work on hydrocarbon
constituents of marine organisms has been primarily undertaken with an
aim other than structural chemical, in this case often geochemical or phylogenetic. Some examples of recent research include the hydrocarbon composition of some blue-green algae, including several marine species (Winters et
ai, 1969) and the most extensive survey to-date of twenty-four species of
green, red, and brown marine algae (Youngblood et ai, 1971). These workers
identified several new hydrocarbons, a C 16 compound containing a cyclopropane group (tentatively) from the green algae Ulva lactuca and Enteromorpha compressa and a number of Ci 7 , C 19 , and C 2i mono to hexaolefins,
none conjugated. The authors (Youngblood et ah, 1971) made the interesting
observation that in one alga, Ascophyllum nodosum the polyunsaturated
hydrocarbons occurred exclusively in the reproductive tissue of the plant.
The C 2 i hexaene, all c/s-3,6,8,12,15,18-heneicosahexaene, has also tentatively been identified by Lee et al. (1970) from the marine diatom Skeletonema