MODELOS MATEMÁTICOS

extraction, distillation and use

Tatyana Stoeva

INTRODUCTION

The essential oil (EO) of Geranium macrorrhizum is produced solely in Bulgaria and the industry dates back to the end of the nineteenth century (Guenther, 1950;

Gildemeister and Hoffman, 1959; Irinchev, 1956). The above-ground herbage is har-vested in the autumn (September–October). In post-flowering plants, the EO content was found to be higher (0.083–0.13 per cent) than during flowering (0.05 per cent).

Herbage consists of 43–49 per cent leaf blades, 39–43 per cent leafstalks, 4–8 per cent yellowing or withered leaves and flowers and 5–10 per cent rhizomes (Irinchev, 1956;

Georgiev, 1995). In recent years, the availability of the wild source of G. macrorrhizum became scarce and is unavailable for industrial usage due to the new biodiversity pro-tection laws and conservation strategies. The only way to solve the lack of resource was to amend the cultivation and increase plant productivity.

ESSENTIAL OIL DISTILLATION

Essential oil distillation is done in the same distillation vessels as those where pepper-mint and lavender are processed. The main methods used are: water distillation, steam and water distillation and steam distillation.

During steam distillation, the herbage is preventing from immersion by supporting it, without compaction, or by the use of 1–2 perforated grids, and the process proceeds at 120 kg/cubic meter.

In water plus steam distillation, it requires 80–85 kg herbage per cubic meter, the boiling water being poured in at a rate of 1:5–6. Distillation is continued for 3.4–4.5 h at a speed of 5–6 per cent and a temperature of the distillation of 45–50 °C as the EO components crystallise out at lower temperatures. About 48 per cent of the oil is obtained during the first hour, with 17–22 per cent obtained after the second and third hour. Since the distillate waters contain 15–20 per cent of the total oil, they are coha-bated for 1.5–2 h and 80 per cent of the EO in the water is isolated during the first hour (Irinchev, 1956; Georgiev, 1995).

Primary and secondary oils are rectified separately. They are left in a warm place for precipitation of admixtures to occur and then are filtered while hot. The commercial EO is prepared by combining the primary (raw) and secondary (cohabated) oils in a pro-portion of 8:1. According to the temperature, the EO is a yellow-green to dark green liquid (above 35 °C) or a semi-solid mass which consists of a mixture of colourless to

Essential oil of Geranium macrorrhizum 37 pale-yellow crystals (stearoptene) with a liquid (eleoptene) at room temperature (Irinchev, 1956; Georgiev, 1995; Ivanov et al., 1952).

The odour is typically ‘zdravetz’: it is a pleasant, reminiscent of clary sage, orris and rose (Guenther, 1950). The Physico-chemical characteristics of G. macrorrhizum are as shown in Table 6.1.

ESSENTIAL OIL COMPOSITION

The EO is typically sesquiterpenic, as the major component is germacrone (50–55 per cent) which constitutes the stearoptene. The other terpenes are mainly ketones: - and

-elemenone, germazone etc. Hydrocarbons account for 11–13 per cent, comprising:

- and -selinene; -elemene, ar-curcumene, -santalene, caryophyllene, -humulene,

-muurolene, -cadinene, calamenene etc. Alcohols make up 10–20 per cent, including:

juniperic camphor, junenol, -eudesmol, elemol. Monoterpenic compounds amount to 7–10 per cent, consisting of -terpinene, terpinolene, -cymene, -pinene, -3-carene,

-phellandrene, limonene and borneol. The green colour of the oil is due to azulenes (Georgiev, 1995; Georgiev et al., 1989; Ivanov et al., 1952; Ivanov and Ognyanov, 1955;

Ognyanov and Ivanov, 1958a,b; Tsankova and Ognyanov, 1972). The EO should be stored in 5 kg copper canisters (kumkuma) under standard conditions for unlimited periods. The oil is usually semi-crystalline at room temperature.

The zdravetz oil is used for its excellent fixative properties in fougeres, chypres, oriental bases, colognes and fantasy fragrances. It blends well with oakmoss, labdanum, olibanum, sandalwood, clary sage, lavender and bergamot (Arctander, 1960).

CONCRETE AND ABSOLUTE OF G. MACRORRHIZUM

Concrete

This is obtained by extraction using petroleum ether at room temperature through a three-step extraction: the first lasts for 40–60 min, the second lasts 20–30 min and the third lasts for 5–15 min at a rate of 120 kg zdravetz herbage per cubic litre

Table 6.1 Physico-chemical characteristics of G. macrorrhizum

Commercial sample 1* Sample 2**

Relative density at 20 °C 0.930–0.952 0.9380–0.9680

Refractive index at 20 °C 1.5024–1.5135 1.5003–1.5189

Optical rotation 4.8 to 8.6 not given

Melting point 34–50 °C 34–50 °C

Ester value 4.97–7.91 7–15

Ester after acetylation 20.8–49.8 25–55

Free alcohols (as geraniol) 5.8–11.9 2–7.5

Total alcohols (as geraniol) 7.7–14.5 6.8–20.7

Stereopten content not given 41.7–52.8

Notes

*Ognyanov and Ivanov (1958);

** Georgiev et al. (1989).

38 Tatyana Stoeva

solvent. The herbage is distributed on 4–6 perforated grids. The concrete yields 0.35–0.40 per cent. It looks like a vaseline-like green to yellow-green mass with a strong typically zdravetz odour but much milder, fuller and more lasting than the EO produced by distillation.

The concrete contains: geraniol, germacrol, mono and bicyclic sesquiterpenes; sesquiter-pene alcohol, free acids, paraffins, dyes etc. It should be stored in 5 kg tin-plated containers for up to 2 years (Guenther, 1950; Gildemeister and Hoffman, 1959;

Georgiev, 1995; Georgiev et al., 1989).

Applications in perfumery: as a rose-scented aromatic with green and fresh notes, exhibiting good fixative values.

Figure 6.1 Geranium macrorrhizum.

Essential oil of Geranium macrorrhizum 39 Absolute

The absolute is applied in different perfume compositions (Zhelev, 1971; Nikolov et al., 1971). It is a dark green thick liquid obtained from zdravetz concrete by extraction with 95 per cent ethyl alcohol. The absolute has strong, penetrative powers but a gentle zdravetz odour with strong fixative properties.

The remaining mass after the absolute is extracted consists of a dark green solid mat-ter containing mainly n-triacontane. It is fatty, tasteless, with a pleasant zdravetz odour and possesses strong photoprotective properties (Georgiev, 1995; Toleva et al., 1971;

Toleva and Tolev, 1956). The zdravetz oil and concrete also had antibacterial and antimycotic activity. (Zhelev, 1971; Nikolov et al., 1971; Toleva et al., 1971).

Figure 6.1 shows a typical example of Geranium macrorrhizum.

REFERENCES

Arctander, S. (1960) Perfume and Flavor Materials of Natural Origins, Elisabeth, New Jersey.

Georgiev, E. (1995) Technologia na estestvenite I sintetichni aromatni producti, Zemizdat, Sofia.

Georgiev, E., Dimitrov, D. and Angelakova, M. (1989) Spravochnik na specialista po aromatichnata I kozmetichna promishlenost, Technika, Sofia.

Gildemeister, E. and Hoffmann, Fr. (1959) Die ätherischen Öle. Bd. 5, Academie Verlag Berlin.

Guenther, E. (1950) The Essential Oils, vol. 4, D. Van Nostrand Company, Inc., Toronto, New York, London.

Irinchev, I. (1956) Zdravetzovo maslo. Priroda, 5(2), 65–67.

Ivanov, D., Ognyanov, I. and Nikolov, N. (1952) Sur l’huile de zdravetz bulgare, Compt. Rend.

Acad. Bulg. Sci., 5, 33–36.

Ivanov, D. and Ognyanov, I. (1955) Bulgarian zdravetz oil. II. Sesquiterpenic hydrocarbons from oil, Compt. Rend. Acad. Bulg. Sci., 8, 45–48.

Nikolov, N., Blagoeva, I. and Boyadzhiev, P. (1971) Aromatnie produkti iz Geranium macro-rrhizum. In: Congress International des huilles essentielles, Tbilissi (USSR), Sept. 1968, vol. 1, Chimie et Technologie des huilles essentielles et des substances odorantes. Pishchevaya promishlenosti, Moscow, p. 248

Ognyanov, I. and Ivanov, D. (1958a) Bulgarian zdravetz oil III. Its terpene compounds, Compt.

Rend. Acad. Bulg. Sci., 11, 379–382.

Ognyanov, I. and Ivanov, D. (1958b) Bulgarian zdravetz oil IV. Sesquiterpene oxygen com-pounds in the oil is eleoptene. Compt. Rend. Acad. Bulg. Sci., 11, 469–472.

Toleva, P. and Tolev, I. (1965) Des possibilities d’utilizer l’huile essentielles et la concrete de Geranium dans la preparation de produits de cosmetique. Travaux Scientifiques de ITSIA, 12, 133–136.

Toleva, P., Hristov, D., Georgieva, A. and Surtalova, T. (1971) Issledovanie sostava voskov iz konkretov zdravetz I akatzii I vozmozhnosti ih ispolizovaniya. In: Congress International des huilles essentielles, Tbilissi (USSR), Sept. 1968, vol. 1, Chimie et Technologie des huilles essentielles et des substances odorantes. Pishchevaya promishlenosti, Moscow, pp. 362–367.

Tsankova, E. and Ognyanov, I. (1972) Sesquiterpene hydrocarbons in the Bulgarian zdravetz (Geranium macrorrhizum L.) oil. Compt. Rend. Acad. Bulg. Sci., 25, 1229–1231.

Zhelev, Z. (1971) Aromatischeskie produkti iz zdravetza In: Congress International des huilles essentielles, Tbilissi (USSR), Sept. 1968, vol. 1, Chimie et Technologie des huilles essentielles et des substances odorantes. Pishchevaya promishlenosti, Moscow, pp. 97–99.

INTRODUCTION

Geranium species are common throughout temperate regions and are used in many different parts of the world in traditional systems of medicine. ‘Geranium oil’ is also widely used, however this normally refers to the essential oil (EO) distilled from Pelargonium species rather than Geranium. In general, most species are used for similar disorders, although some of the different local indications for each are given in Table 7.1. Geraniums used medicinally usually contain high levels of tannins, which are responsible for the folklore use as haemostatics and astringents. They are used internally for haemorrhage and diarrhoea, and externally for wounds, grazes, sores and fissures (British Herbal Pharmacopoeia, 1983; Brendler et al., 1999). More recently various tannin-containing drugs, including Geranium species, have been used as antiinfective agents particularly for viral diseases (Serkedjieva and Hay, 1998) and antioxidant activity, which would be expected from the content of polyphenolic compounds, has also been demonstrated (Lamaison et al., 1993).

EUROPEAN AND AMERICAN HERBAL MEDICINE

Geranium maculatum L.

The species most commonly used worldwide is probably G. maculatum L., variously known as American cranesbill, storksbill, spotted cranesbill, crowfoot and others.

This species is found in shady and moist ground throughout the whole of Europe and in North America from Newfoundland to Manitoba and as far south as Missouri.

Both the rhizome and the herb have been used for medicinal purposes since antiquity to treat fever, including malaria, abdominal and uterine disorders, inflammation and as an external application for wounds, excessive bleeding, and sores. Internally it was used as a styptic for metrorrhagia, menorrhagia, haematuria and haemorrhoids; and particularly for diarrhoea, peptic and duodenal ulcers and dysentery. These are still the most important indications. In the middle ages, Paracelsus described it as having cardiotonic and antidepressive activity, and there are other uses for which Geranium has been suggested, including worms, leucorrhoea and as a mouthwash (Brendler et al., 1999).

7 Use of Geranium species extracts