1. FATTY ACID OCCURRENCE AND DISTRIBUTION
47
tung (Aleurites cor data), elaborate oils rich in eleostearic acid. In the
seed oils of other species, such as conophor (Tetracarpidium
conophorum Awusa), which contains much (63-68%) linolenic acid, there
are no unusual acids (244). Castor (Ricinus communis) seed oil stands
apart with its high content (approximately 90%) of ricinoleic acid (3).
TABLE XIII
COMPONENT FATTY ACIDS (WEIGHT %) OF ROSACEAE SEED FATS
Species
Palmitic Stearic Oleic Linoleic
Polyenoic
Licania rigida (242)
<
11
> 6
5
61 (licanic),
17 (eleostearic)
Parinarium laurinum (243)
4
1
10
4
51 (parinaric),
30 (eleostearic)
The same acid was believed to occur to the extent of 33% in the seed oil
of Cephalocroton cordofanus, which also belongs to the same family.
However, the acid has since been shown to be vernolic (cis-12,13epoxyoctadec-cis-9-enoic) acid (245).
Other examples of the occurrence of unusual fatty acids in the
Euphorbiaceae include that of ω-hydroxyeleostearic acid, the main constituent of kamala (Mallotus philippinensis) seed oil (36, 246), deca2,4-dienoic acid found in minor amounts in Stillingia (Sapium sebiferum-chinese tallow tree) seed oils (29) and the corresponding dodeca2,4-dienoic acid which occurs in Sebastiana ligustrina (247).
The Cucurbitaceae seed fats are mostly linoleic acid-rich fats with
considerable proportions of oleic acid. A few species, however, contain
in their seed oils, in addition, trichosanic acid, which is now considered
to be identical with punicic (octadeca-cis-9,ds-ll,£rans-13-trienoic)
acid (248, 249), the major constituent of pomegranate (Tunica granatum, family Punicaceae) seed oil. Although the Compositae family
have been classified in the linoleic acid-rich group it is appropriate to
mention here that one species, Scots marigold (Calendula officinalis),
contains in its seed oil the unique acid, octadeca-8,10,12-trienoic acid.
It is believed to be the all-trans isomer and therefore related to
ß-eleostearic acid (250) and classifiable in group (2).
(3) Seed fats containing, as major component acids, palmitic oleic,
and linoleic acids. In this group the following families are represented:
Berberidaceae, Magnoliaceae, Anonaceae, Rutaceae, Zygophyllaceae,
Anacardiaceae, Capparidaceae, Hernandiaceae, Tiliaceae, Malvaceae,
Bombacaceae, Caryocaraceae, Caricaceae, Lecythidaceae, Combretaceae, Apocynaceae, Amarantaceae, Martyniaceae, Acanthaceae, Bignoniaceae, Rubiaceae, and Caprifoliaceae.
47
tung (Aleurites cor data), elaborate oils rich in eleostearic acid. In the
seed oils of other species, such as conophor (Tetracarpidium
conophorum Awusa), which contains much (63-68%) linolenic acid, there
are no unusual acids (244). Castor (Ricinus communis) seed oil stands
apart with its high content (approximately 90%) of ricinoleic acid (3).
TABLE XIII
COMPONENT FATTY ACIDS (WEIGHT %) OF ROSACEAE SEED FATS
Species
Palmitic Stearic Oleic Linoleic
Polyenoic
Licania rigida (242)
<
11
> 6
5
61 (licanic),
17 (eleostearic)
Parinarium laurinum (243)
4
1
10
4
51 (parinaric),
30 (eleostearic)
The same acid was believed to occur to the extent of 33% in the seed oil
of Cephalocroton cordofanus, which also belongs to the same family.
However, the acid has since been shown to be vernolic (cis-12,13epoxyoctadec-cis-9-enoic) acid (245).
Other examples of the occurrence of unusual fatty acids in the
Euphorbiaceae include that of ω-hydroxyeleostearic acid, the main constituent of kamala (Mallotus philippinensis) seed oil (36, 246), deca2,4-dienoic acid found in minor amounts in Stillingia (Sapium sebiferum-chinese tallow tree) seed oils (29) and the corresponding dodeca2,4-dienoic acid which occurs in Sebastiana ligustrina (247).
The Cucurbitaceae seed fats are mostly linoleic acid-rich fats with
considerable proportions of oleic acid. A few species, however, contain
in their seed oils, in addition, trichosanic acid, which is now considered
to be identical with punicic (octadeca-cis-9,ds-ll,£rans-13-trienoic)
acid (248, 249), the major constituent of pomegranate (Tunica granatum, family Punicaceae) seed oil. Although the Compositae family
have been classified in the linoleic acid-rich group it is appropriate to
mention here that one species, Scots marigold (Calendula officinalis),
contains in its seed oil the unique acid, octadeca-8,10,12-trienoic acid.
It is believed to be the all-trans isomer and therefore related to
ß-eleostearic acid (250) and classifiable in group (2).
(3) Seed fats containing, as major component acids, palmitic oleic,
and linoleic acids. In this group the following families are represented:
Berberidaceae, Magnoliaceae, Anonaceae, Rutaceae, Zygophyllaceae,
Anacardiaceae, Capparidaceae, Hernandiaceae, Tiliaceae, Malvaceae,
Bombacaceae, Caryocaraceae, Caricaceae, Lecythidaceae, Combretaceae, Apocynaceae, Amarantaceae, Martyniaceae, Acanthaceae, Bignoniaceae, Rubiaceae, and Caprifoliaceae.