Schriften zu Genetischen Ressourcen - Genres

H. SCHULZ
During the recent years, rosemary extracts with high percentages of carnosic acid
and pure rosemaric acid are increasingly used for cosmetics because of their multifunctional
effects. Beside antioxidative, antimicrobial and antiphlogistic properties
also an improvement of the membrane stability could be demonstrated in various
cosmetic formulations. More than the European native plants, rather the exotic species
such as Aloe vera and green tea are currently playing a leading role in the trend.
It has been found that polyphenols occurring in green tea extracts protect the skin
from free radicals and possess antibacterial and anti-inflammatory effects. According
to the latest findings, also extracts made from the South African rooibos (Aspalathus
linearis) have antimutagenic, anti-carcinogenic and anti-inflammatory properties. The
antioxidant activity is mainly related to the flavonoids, especially both aspalathin and
nothofagin which cause an acceleration of the healing process in various skin diseases
such as eczema or sun burn. Because of these activities, rooibos extracts are
used in South Africa especially in baby products in the form of creams or soaps.
Furthermore, it has been observed that the flavonoid quercetin blocks the histamine
release from the mast cells and so it reduces allergic reaction in man.
Cultivation and production of essential oils
In the first half of the 19 th century, the production of essential oils was industrialised
due to the increased demand for these raw materials as perfume or flavour ingredients.
Companies such as Schimmel and Co. in Miltitz near the city of Leipzig were
founded at this time (GILDEMEISTER and HOFFMANN 1916). In the 19 th century, Leipzig
was a centre for the production of essential oils and other plant extracts derived from
ginger, cinnamon, sandalwood as well as chamomile and lavender. Around the town
of Leipzig, roses and other important fragrance plants were cultivated on large fields.
The majority of essential oils are mixtures of various mono- and sesquiterpenoids.
Besides, also many other aromatic substances exist, including phenols. The amount
and composition of essential oils may also vary with the time of harvesting and with
the applied distillation process.
Liverworts are rich sources of terpenoids and phenolic compounds, and many of
them show interesting pharmacological activity. But the great majority of commercially
available essential oils is produced from seed plants (MERKEL 1972, RASSMANN
1989, HEGNAUER 1978).
Agrumen or citrus oils are obtained from leaves, blossoms, fruits or fruit peels of
various citrus species. Usually the oils of orange, grapefruit, mandarin, lemon and
lime are obtained by pressure from the fruits and fruit peels. So-called “Petitgrain oil”
is produced from nearly all citrus species but predominantly from leaves and twigs of
bitter orange trees. Neroli oil is obtained by steam distillation of the blossoms of the
bitter orange tree. Main components responsible for the characteristic, fresh citrus
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