2VOLATILE OILS All official volatile oils are of vegetable origin. Normally pre-exist in the plant – stored in a special secretory tissue (e.g. Citrus peel oil cells or oil ducts in umbelliferous fruits).EXCEPTION: Oil of bitter almond – formed by hydrolysis of the glycosides.
3USES OF VOLATILE OILS Therapeutically (Oil of Eucalyptus) Flavouring (Oil of Lemon)Perfumery (Oil of Rose)Starting materials to synthesize other compounds (Oil of Turpentine)Anti-septic – due to high phenols (Oil of Thyme). Also as a preservative (oils interfere with bacterial respiration)Anti-spasmodic (Ginger, Lemon balm, Rosemary, Peppermint, Chamomile, Fennel, Caraway)Aromatherapy
4DEFINITION OF VOLATILE OILS Volatile oils are products which are generally complex in composition, consisting of the volatile principles contained in plants, and are more or less modified during the preparation process.Only 2 procedures may be used to prepare official oilsSteam distillationExpression4 Main types of volatile oilsConcretesPomadesResinoidsAbsolutes
5CONCRETESPrepared from raw materials of vegetable origin (bark, flowers, leafs, roots etc.)Extracted by HC type solvents, rather than distillation or expression – Becomes necessary when the essential oil is adversely affected by hot water or steam (e.g. jasmine).Produces a more true-to-nature fragrance.
6CONCRETESConcretes contain about 50 % wax and 50 % essential oil (jasmine).Ylang ylang (concrete volatile) contains 80 % essential oil and 20 % wax.Advantages of concretes: they are more stable and concentrated than pure essential oils.
7POMADESTrue pomades are (volatile oil) products of a process known as enfleurage (hot or cold).Enfleurage is used for obtaining aromatic materials from flowers containing volatile oils to produce perfume long after they were cut.
8ENFLEURAGE: METHODA glass plate is covered with a thin coating of especially prepared and odourless fat (called a chassis).The freshly cut flowers are individually laid on to the fat which in time becomes saturated with their essential oils. The flowers are renewed with fresh material.Eventually the fragrance-saturated fat, known as pomade, may be treated with alcohol to extract the oil from the fat.
9RESINOIDSPrepared from natural resinous material (dried material) by extraction with a non-aqueous solvent, e.g. Petroleum ether or hexane.E.g. Balsams – Peru balsam or benzoin; resins (amber or mastic); Oleoresin (copaiba balsam and turpentine); Oleogum resins (frankincense and myrrh)
10RESINOIDS Can be viscous liquids, semi-solid or solid. Usually homogeneous mass of non-crystalline character.Uses: in perfumery as fixatives to prolong the effect of a fragrance.
11ABSOLUTESObtained from a concrete, pomade, or a resinoid by alcoholic extraction.The extraction process may be repeated.The ethanol solution is cooled & filtered to eliminate waxes.The ethanol is then removed by distillation.They are usually highly concentrated viscous liquids.
13Fx OF VOLATILE OILSIn most cases, the biological function of the terpenoids of essential oils remains obscure – it is thought that they play an ecological role – protection from predators & attraction of pollinators.
14LOCALIZATIONSynthesis & accumulation of essential oils are generally associated with the presence of specialized histological structures, often located on or near the surface of the plant:- Oil cells of Zingiberaceae- Glandular trichomes of Lamiaceae- Secretory cavities of Myrtaceae or Rutaceae- Secretory canals of Apiaceae or Astereraceae (Compositeae)
15VOLATILE OIL COMPOSITION Mixtures of HC’s and oxygenated compounds derived from these HC’s.Oil of turpentine – mainly HC’sOil of Clove – mainly oxygenated compoundsEXCEPTION: Oils derived from glycosides (e.g. bitter almond oil & mustard oil).Oxygenated compounds – responsible for the odour/smell of the oil. They are slightly water soluble – Rose water & Orange Water; more alcohol soluble.Most volatile oils are terpenoid. Some are aromatic (benzene) derivatives mixed with terpenes.Some compounds are aromatic, but terpenoid in origin (e.g. Thymol – Thyme)
16CHEMICAL COMPOSITIONVolatile oils are divided into 2 main classes based on their biosynthetic originTerpene derivatives (formed via the acetate mevalonic acid pathway)Aromatic compounds (formed via the shikimic acid-phenylpropanoid route)Miscellaneous Origin
17A. TERPENESTerpenes, or terpenoids, are the largest group of secondary products (metabolites).They are all formed from acetyl CoA or glycolytic intermediates.
18CLASSIFICATION OF TERPENES All terpenes are formed from 5-C elementsIsoprene is the basic structural element.
19CLASSIFICATION OF TERPENES Terpenes are classified by the number of 5-C atoms they contain10-Carbon terpenes (contain 2 C-5 units) – monoterpenes15- Carbon terpenes (3 C-5 units) are called sesquiterpenes.20-carbon terpenes (4 C-5 units) are diterpenes.Larger terpenes (30 Carbons) are called triterpenes (triterpenoids), 40 Carbons – called tetraterpenes and polyterpenoids.
20TERPENOIDSTerpenoids contain only the most volatile terpenes (i.e. molecular weight is not too high) mono and sesquiterpenesMay occur as oxygenated derivatives, e.g. alcohols, aldehydes, ketones, phenols, oxides & esters.
21EXAMPLES OF TERPENESLIMONENEMENTHOLBORNEOLSESQUITERPENES
25iv. SESQUITERPENES (Contain 3 isoprene units) Acyclic – E.g. Farnesol Monocyclic – E.g. BisobololBicyclic e.g. Chamezulene (Chamomile)
26B. AROMATIC COMPOUNDSMany are phenols are phenol estersE.g. Vanillin
27PROPERTIES OF VOLATILE OILS Almost entirely volatile without decomposition.Density: Most are less than 1g/ml.2 are heavier – Oil of Cinnamon and Clove oil.Soluble in ether, chloroform & alcohol.Slightly soluble in water: give it a characteristic odour & taste.Leaves a temporary translucent stain on paper which disappears as the oil volatilizes.Most are colourless. Oxidize on exposure to air and resinify colour becomes darker (odour changes slightly).All are characteristic odours.Most are optically active.
28PRODUCTION OF ESSENTIAL OILS Essential oils may be producedBy steam- Simple steam distillation- Saturated steam distillation- HydrodiffusionBy expressionOther MethodsConcretes & Resinoids may be producedBy solvent extractionBy methods using oils & fatsBy extraction by supercritical gasses
29ESSENTIAL OILS: i.STEAM DISTILLATION a. SIMPLE STEAM DISTILLATIONPlant material is immersed directly in a still filled with water. This is then brought to a boil.Heterogeneous vapours are condensed on a cold surface.Essential oil separates based on difference in density and immiscibility.
30b. SATURATED STEAMPlant does not come into contact with the water steam is injected through the plant material placed on perforated trays.It is possible to operate under moderate pressure.Advantages: Limits the alteration of the constituents of the oilIt shortens the duration of the treatmentIt conserves energyIt can also be conducted on on-line in automated set ups.
31c. HYDRODIFFUSIONPulses of steam is sent through the plant material at very low pressure from (top to bottom).ADVANTAGE: Normally produces a product of high quality.Saves time and energy.
32EXPRESSION (E.G.OF CITRUS EPICARPS) The rind is lacerated, and the contents of the ruptured secretory cavities are recovered.CLASSIC PROCESS: an abrasive action is applied on the surface of the fruit in a flow of water. The solid waste is eliminated, and the essential oil separated from the aqueous phase by centrifugation.OTHER machines break the cavities by depression, and collect the essential oil directly prevents the degradation linked to the action of water.
33EXPRESSION OF CITRUS EPICARPS Most facilities allow for the simultaneous or sequential recovery of the fruit juice and of the essential oil, by collecting the oil with a spray of water after the abrasion (scarification – puncture by pins) before or during the expression of the fruit juice.Enzymatic treatment of the residual water allows recycling, and markedly increases the final yield of essential oil.Citrus oils are also obtained directly from the fruit juices (by vacuum de-oiling)
34iii. OTHER METHODSSteam distillation by microwaves under vacuum. In this procedure, the plant is heated selectively by microwave radiation in a chamber inside which the pressure is reduced sequentially.fresh plants require no added water.ADVANTAGE: This method is fast, consumes little energy and yields a product which is most often of a higher quality than the traditional steam distillation product.
35PRODUCTION OF CONCRETES & RESINOIDS SOLVENT EXTRACTIONExtraction is generally preceded by a process of: bruising the fresh, wilted or semi-desiccated organs, chopping herbaceous drugs, pounding roots & rhizomes or turning wood into chips or shavings.The procedure is conducted in specialized facilities e.g. Soxhlet-type extractor.
36SOLVENT EXTRACTIONThe solvent selection is influenced by technical & economical factors- Selectivity (being a good solvent for the specific constituents).- Stability (chemical inertness)- Boiling point should not be so high that the solvent can be completely eliminated; nor too low, to limit losses & control cost- Handling safetySolvents most used are aliphatic HC’s – petroleum ether, hexane, propane & liquid butane.Although benzene is a good solvent, its toxicity increasingly limits is use.
37SOLVENT EXTRACTIONAt the end of the procedure, the solvent contained in the plant material is recovered by steam injection.Main disadvantages of solvent extraction- Lack of selectivity, many lipophilic substances may end up in the concretes & render further purification necessary.- The toxicity of solvents leads to the restrictive regulations regarding their use- Residues in the final product.
38ii. METHODS USING OILS & FATS These procedures take advantage of the liposolubility of the fragrant components of plants in fats.a. “Enfleurage” – the plant material is placed in contact with the surface of the fat. Extraction is achieved byCold diffusion into the fatDigestion – carried out with heat, by immersing the plant in melted fat (also known as hot enfleurage).The final product is known as a floral pomade.
39METHODS USING OILS & FATS b. PNEUMATIC METHOD: similar in principle to the enfleurage process.It involves the passage of a current of hot air through the flowers.The air, laden with suspended (extracted) volatile oil, is then passed through a spray of melted fat in which the volatile oil is absorbed.
40iii. EXTRACTION BY SUPERCRITICAL GASSES Beyond its critical point, a fluid can have the density of a liquid & the viscosity of a gas therefore diffuses well through solids, resulting in a good solvent.CO2 is the main gas usedAdvantages of CO2- It is a natural product- chemically inert, non-flammable- non-toxic- easy to completely eliminate- selective- readily available- Inexpensive
41EXTRACTION BY SUPERCRITICAL GASSES DISADVANTAGE: Technical constraints- High cost of initial investmentADVANTAGES:- obtain extracts which are very close in composition to the natural product.- It is possible to adjust the selectivity & viscosity, etc by fine tuning the temperature & pressure- All result in the increase of popularity of this type of method
42EXTRACTION BY SUPERCRITICAL GASSES USESInitially developed to decaffeinate coffees, prepare hops extracts or to remove nicotine from tobacco, the method is now used to- Prepare spice extracts (ginger, paprika, celery)- Specific flavours (black tea, oak wood smoke)- Plant oils- To produce specified types of a certain product, e.g. thujoneless wormwood oil.
43TREATMENTS OF THE OILSOccasionally it is necessary to decolourize, neutralize or rectify the oils obtained.Steam jet under vacuumAllows for the elimination of smelly or irritating products, and to obtain a final product of desired “profile”.Chromatrographic techniquesThis permits a good separation of the essential oil from non-volatile lipophilic compounds.
44VARIABILITY FACTORS OF ESSENTIAL OILS Occurrence of ChemotypesInfluence of the vegetative cycleInfluence of environmental factorsInfluence of preparation method
45i. CHEMOTYPESChemical breeds commonly occur in plants containing volatile oils, e.g. Thyme (Thymus vulgaris) – has 7 different chemotypes, each with slightly different types & amounts of volatile oils.
46ii. THE VEGETATIVE CYCLE Proportions of the different constituents of a volatile oil may vary greatly throughout its development. Wide ranges are commonly found in fennel, carrot and coriander (linalool is higher in ripe fruit than unripe fruit). Mentha (peppermint) is also greatly affected by the vegetative cycle.
47iii. ENVIRONMENTAL FACTORS Temperature, humidity, duration of daylight (radiation), and wind patterns all have a direct influence on volatile oil content, especially in those herbs that have superficial histological storage structures (e.g. glandular trichomes). When the localization is deeper, the oil quality is more constant.
48ENVIRONMENTAL FACTORS e.g. Peppermint: long days & temperate nights higher yields of oil & menthofuran. Cold nights lead to an increase in menthol.Laurus nobilis (Bay) [volatile oil] is greater in the southern hemisphere than the northern.Citrus: higher temperatures = higher oil content.
49ENVIRONMENTAL FACTORS Cultivation practices also play an important factor to the yield & quality of the final product.Fertilization and the amounts of N, P and K have been studied for various species.The watering regiment also plays an important role.
50PREPARATION METHODBecause of the volatile nature of the constituents of essential oils, the composition of the product obtained by steam distillation is often different from the constituents originally found in the secretory organs of the plant.During steam distillation, the water, acidity and tempereature may induce hydrolysis of the esters. Rearrangements, isomerizations, racemiazations, oxidations and other reactions also occur, all of which change the composition.
51GINGER: Zingiber officinale Definition: Ginger is the peeled or unpeeled rhizome of Zingiber officinale (Zingiberaceae).Common Names: Jamaican ginger, Ginger
52Zingiber officinalis - Ginger GEOGRAPHICAL SOURCESJamaicaChinaIndia AfricaHISTORYCultivated in India from the earliest times. Used by Greeks and Romans and was a common article of commerce in the European Middle Ages.
53CULTIVATION & PREPARATION Grows well in subtropical temperatures with high rainfall.Grown by vegetative means.Mulching or is necessary as the plant rapidly exhausts minerals from the soil.When the stems wither, the rhizomes are ready for collection.Dried.
54MACROSCOPICAL FEATURES Scraped/peeled herb has little resemblance to the fresh herb (loss in weight & shrinkage).Occurs in branched pieces “hands” or “races”.BudsNo corkAromatic odour & pungent taste.Unscraped rhizome: resembles scraped herb –Covered with cork (brownish layers)
55MICROSCOPICAL FEATURES Cork cells – high starch contentCork cells are absent in the scraped drug.Outer zone of flattened parenchyma & inner zone of normal parenchyma.Oil cells scattered in the cortex.
57Zingiber officinale VARIETIES ALLIED DRUGS ADULTERANTS Chinese Ginger – slicedAfrican ginger – darker (cortex is grey – black in colour); lacks the odour but more pungent than Jamaican herb.ALLIED DRUGSJapanese ginger – Z. miogaPreserved ginger – undried rhizomes preserved by boiling in syrup.ADULTERANTSSpent gingerVegetable adulterants (detected with microscopical examination).
60CARDAMOM FRUIT & OILDEFINITION: Cardamom consists of the dried, nearly dried ripe fruits of Elettaria cardamomum var miniscula (Zingiberaceae).PARTS USED: Seeds (should be kept in the fruit until ready to be used – Prevents loss of volatile oils).(3RD most expensive spice).
61Elettaria cardamomum GEOGRAPHICAL SOURCES HISTORY Sri Lanka India GuatemalaHISTORYTraditional Indian ceremonies
62PRODUCTION, COLLECTION & PREPARATION Mainly obtained from cultivated plants (propagated by seedlings or vegetatively [problematic due to virus infection]).Capsules on the same plant ripen at different times – important to collect them before they split.
63COLLECTION & PREPARATION Fruits are dried slowly (outdoors or indoors).Too rapid drying – capsules split & shed seedsCalyx at the apex of the stalk and the stalk at the base may be removed.Fruits are graded with a sift into ‘longs’, ‘mediums’, ‘shorts’ & ‘tiny’.If they have been sulphur – bleached (improved colour), it will be aired outdoors before packed for transport.
64MACROSCOPICAL FEATURES Plant is reed-like - > 4 m, with long leaves growing from the rhizome.Fruits – capsular: inferior, ovoid, 1-2 cm long.Apex: shortly beaked & shows floral remains.Base: rounded & shows the remain of a stalk.Internally the capsule is 3-celled; each cell contains x2 row of seeds.Each seed: Slightly angular, 4mm long & 3 mm broad.Colour: dark red-brown (fully ripe seeds) paler in unripe seeds.Strong, pleasant, aromatic odourPungent taste
65MICROSCOPICAL FEATURES Oil cellsPredominant Parenchyma (yellow colour)Cells containing silicaStarch grains
66VARIETIES & ADULTERANTS ADULTERATIONPowdered drug adulterated with the fruit pericarp (powdered).ALLIED HERBSOfficial variety – E. cardamomum var minisculaOther: E. cardamomum var major (more elongated & sometimes 4 cm long with dark brown pericarps)Amomum aromaticum (Bengal cardamom)Amomum subulatum (Nepal cardamom)Amomum cardamomum (Java cardamom)
68Elettaria: ACTIONS & USES Flavouring agent (curries & biscuits)Liqueur manufactureSmall amount is used for pharmaceutical manufacture (Compound Tincture of Cardamom).
69CINNAMON: Cinnamomum zeylanicum DEFINITION: Cinnamon is the dried bark of Cinnamomum zeylanicum (Lauraceae).GEOGRAPHICAL SOURCESCultivated in Sri Lanka, South India, Seychelles, Madagascar, Martinique, Cayenne, Jamaica & Brazil.
70CULTIVATION, COLLECTION & PREPARATION Grown from seedCut down when 2-3 years old.After 5-6 shoots grow from the stump (18 months), shoots are harvested, trimmed and fermented.Bark is removed.Peeled bark is then stretched over a suitable stickOuter cortex is removed.
71PREPARATION OF Cinnamomum Individually scraped barks are placed inside each other.Compound quills are dried on wooden frames in the open air without exposure to direct sunlight.Sorted into grades.
72MACROSCOPICAL FEATURES Normally received in shorter lengths known as ‘cigar lengths’.Consists of a single or double compound quill about 6-10 mm diameter of varying length.Thickness of the quill varies according to grade (good quality: Not > 0.5mm), bark: mm.External surface: is yellow-brown, shining, wavy lines (pericycle fibres) and occasional scars & holes (leave/twig positions).Inner surface: darker, longitudinally striated.Odour: fragrantTaste: Warm, sweet & aromatic
73MICROSCOPICAL FEATURES Transverse: absence of epidermis & corkSclereids (thickened lignified pitted walls)Secondary phloem is composed of phloem parenchyma containing oil & mucilage cells, phloem fibres & medullary rays.Some phloem parenchyma contain tannins.Secretion cells: volatile oils and mucilageCalcium oxalates
74Cinnamomum - CONSTITUENTS Volatile oils (at least 1.2 %)PhlobaphenesMucilageCalcium OxalateStarch
75CINNAMON OIL – ADULTERATION & ALLIED HERBS AdulterantsCinnamon Leaf OilOil of CassiaAllied HerbsCayenne Cinnamon – C. zeylanicum grown in Brazil – not used in BritainC. loureirii – from Vietnam – Closely resembles C. cassia
77LEMON PEELDefinition: Dried lemon (Limonis Cortex) peel is obtained from the fruit of Citrus limon (Rutaceae).Botanical Description:Small tree, growing to 3-5 m in height.Geographical SourcesMediterranean Regions
78Limonis Cortex – COLLECTION & PREPARATION Lemons are collected in January, August & November, before the green colour changes to yellow.The smaller fruit, which would not be sold on the produce market, are used in the preparation of oil of lemon - the peel is removed with a sharp knife in the form of a spiral band.
79Limonis Cortex – CHARACTERISTICS Dried lemon peel occurs in spiral bands (2 cm wide; 2-3 mm thick).The outer surface is rough & yellow; the inner surface is pulpy & white (anatomically similar to that of an orange peel).Odour: Strong & characteristicTaste: aromatic & bitter
80Limonis Cortex – CONSTITUENTS & USES Should contain at least 2.5% volatile oilVitamin CHesperidin (Flavonoid)MucilageCalcium OxalateUSESFlavouring purposes
81LEMON OILS - Oleum limonis Definition: Lemon oil is the oil expressed from the outer part of the fresh pericarp of the ripe or nearly ripe fruit of Citrus limon (Rutaceae).BP: oil should be obtained by suitable mechanical means, without the use of heat, from the fresh peel.Much oil is derived via steam distillation, but this process yields oil of inferior quality.Distilled oil of lemon is much cheaper than that prepared by expression. Large amounts are used for non-pharmaceutical purposes.Geographical Sources:Mediterranean, North & South America, Australia & parts of Africa.
82Preparation of Lemon Oils i. Hand MethodsNo longer applicable to pharmaceutical oils
83Production of Lemon Oils Machine ProcessesQuality is inferior to the best hand-pressed oils.Machines are designed to release oils from the peel via puncture, rasting or cutting and by imitating the gentle squeezing action of the sponge method. (Superiority of the sponge method is due to the fact that there is no contact between the oil & the inner white part of the skin.The newer machines extract oil more completely than the older ones and give a higher yeildDistilled OilsAlthough not official, some lemon oils are produced by distillation, mainly from the residue of the expression processes. It is much cheaper than hand-pressed or machine-made oil.
84Oleum limonis - CONSTITUENTS Terpenes – mainly limoneneSesquiterpenesAldehydes (Citral & Citronella)EstersLemon oil has a tendency to resinify and should be protected from the action of air & light as much as possible.
85Oleum limonis – ADULTATION & USES ADULTERATIONOil of turpentineTerpenes from ‘terpeneless oil of lemon’Distilled oil of lemonOil of lemon-grassUSESPerfumeryFlavouring
86TERPENELESS LEMON OILDefinition: Oil prepared by concentrating lemon oil in vacuum until most of the terpenes have been removed, or by solvent partition. The concentrate is a terpeneless oil, which has a citral content of %.It is equal in flavouring to times its volume of lemon oil
88Agathosma betulina – CONSTITUENS & USES CONSTITUENTSVolatile oilsPulegoneMenthone & isomenthonelimoneneDiosminMucilageResinCalcium oxalatesBuchu camphor – Responsible for the diuretic actionUSES/ACTIONSDiureticUrinary Tract Anti-Septic – Used for UTI’s
89NUTMEG & NUTMEG OILDefinition: Nutmeg is the dried kernel of the seed of Myristica fragrans (Myristicaceae).Geographical SourcesIndigenous to the Molucca Islands (Spice Islands)Cultivated in Indonesia, Malaysia & the West Indies.
90NUTMEG – Myristica fragrans HISTORYFirst Introduced to the Europeans by the Arabs.Portuguese lost control of the spice trade to the Dutch, who maintained complete monopoly by destroying all trees in the neighbouring islands & preventing the export of living seeds.
91CULTIVATION, COLLECTION & PREPARATION Trees can be grown from fresh seed gown in the shell. The seeds germinate after about 5 weeks. When the plants are 6 months old, they are transplanted to the fields.Nutmegs are dried in the shells (process differs according to local conditions). Normally they are dried in the sun & covered at night & rainy weather. They can also be dried in the oven or over low flames.When completely dried, the kernel rattles in the testa, which is then cracked & the nutmeg extracted.
92MACROSCOPICAL FEATURES Nutmeg trees are evergreen, growing up to 20 m in height.Nutmegs are oval, 2-3 cm long & 2 cm broad.If not heavily limed, the surface is a brown or grey brown in colour.Odour: Strong & aromaticTaste: Pungent and slightly bitter.
93MICROSCOPICAL FEATURES Potassium acid tartrate crystalsParenchym with thin brown wallsOval oil cellsFeathery crystals of fatFew tannin cells (containing tannin & starch)
94NUTMEG – ALLIED HERBSPapua nutmegs – from M. argentea (New Guinea) – little odour & a disagreeable taste.Bombay nutmegs – M. malabarica (India) – lack the characteristic odour of the genuine herb.
95NUTMEG OILNutmeg oil is distilled from the kernels of Myristica fragrans.CONSTITUENTSPineneSabineneCampheneDipenteneSafroleEugenol & eugenol derivativesMyristicin – a benzene: toxic to humans (large does of nutmeg or nutmeg oil may cause convulsions).
96MACECommon mace or Banda mace consists of the dried arillus or arillode of M. fragrans.Description: bright red colour & lacks in aroma.
97MACE – CONSTITUENTS & USES Volatile oils (similar to that of nutmeg) – eugenol derivatives are the main active constituents – responsible for the anti-bacterial effects.Also has 2 anti-microbial resorcinols (Malabaricone B and C)Nutmegs, maces & their oils, are all used forCarminativesFlavouringInfantile Diarrhoea (Tea of nutmeg – Ayurveda).
98CLOVEDEFINITION: Cloves are the dried flower buds of Syzygium aromaticum (Eugenia caryophyllus), (Myrtaceaea).Geographical SourcesMolucca or Clove Islands, Zanzibar, Pemba, Madagascar, Indonesia & Brazil.
99HISTORY OF CLOVECloves were used in China as early as 266 BC, and by the 4th century, they were known in Europe, although very expensive.Same as with nutmeg, the Dutch also destroyed all trees from surrounding native islands to secure a monopoly, and cultivated them only in a small group of islands.In 1770, the French managed to introduce clove trees to Mauritius, and started cultivating them there, as well as in Zanzibar, Penang and Sumatra.
100COLLECTION & PREPARATION The flower buds are collected when the lower part turns green-crimson. The cloves are dried in the open air on mats & separated from their peduncles (forming clove stalks which are also sold commercially).If left on the tree for too long, the buds open & the petals fall, leaving “brown cloves”. Later the fruits (“mother cloves”) are produced.
101MACROSCOPICAL FEATURES Cloves are mm long.The head consists of 4 slightly projecting calyx teeth, 4 membranous petals and numerous incurved stamens around a large style.Odour: Spicy & PungentTaste: Aromatic
102MICROSCOPICAL FEATURES Heavy cuticularized epidermisNumerous oil cells (shizolysigenous)Calcium oxalates (cluster crystals & prisms)Stomata (epidermis of sepals)Starch (Fruit – “mother cloves”)Lignified sclereids
104USES OF CLOVE Stimulant aromatic Spice For the preparation of volatile oilSesquiterpenes: potential anti-carcinogenic compounds
105CLOVE OILOil distilled in Europe and the US normally does not need purification, while oil distilled in other areas (e.g. Madagascar) does. After purification the oil is sold with varying eugenol contents.Oil of cloves is yellow or colourless, is slightly heavier than water.
106CLOVE OIL - CONSTITUENTS Volatile oils – mainly eugenol & acetyleugenolSesquiterpenes (α and β caryophyllenes)Oil of clove – like other volatile/essential oils – should be stored in a well-fitted, air-tight container, & should be protected from light & heat.
109EUCALYPTUS LEAFDEFINTION: Eucalyptus leaf consists of the whole or cut dried leaves of the older branches of Eucalyptus globulus, (Myrtaceae).GEOGRAPHICAL SOURCESPortugal, SA, Spain, China, Brazil, Australia, India & Paraguay.
110Eucalyptus - DESCRIPTION MACROSCOPICALOlder dried leaves are grey-brown & have lateral veins. Secretory oil cells are visible in leaves held to the light.MICROSCOPICEpidermal cells have a thick cuticle.Anisocytic stomataMesophyll has schizogenous oil glandsCalcium oxalate crystals: Prisms & Cluster crystals
111Eucalyptus - CONSTITUENTS Volatile Oil (at least 2 %)sesquiterpene - Anti-bacterial action against oral pathogens.
112EUCALYPTUS OILOil of eucalyptus is distilled from the fresh leaves of various species of Eucalyptus and rectified. They are produced in the same countries which produce the dry herb.Only a certain amount of species produce oil suitable for medicinal use – the main criteria is a high cineole content and low amounts of phellandrene and aldehydes.Suitable oils are obtained from E. polybractea, E. smithii, E. globulus and E. australiana.
113CHARACTERISTICS & CONSTITUENTS Colourless or pale yellow liquidAromatic & camphoraceous in odour.Pungent & camphoraceous in taste, which is followed by a sensation of cold.CONSTITUENTSAt least 70 volatile oils (mainly cineole).
114EUCALYPTUS OIL - USESAlleviating the symptoms of nasopharyngeal infectionsTreating coughsDecongestant.Official preparationsMixtures, inhalations, lozenges and pastilles; also applied externally as ointments and liniments.
115FENNELDEFINITION: Fennel consists of the dried ripe fruits of Foeniculum vulgare (Umbelliferae).GEOGRAPHICAL SOURCESEurope, India, China & Egypt. Mediterranean origin.
119Foeniculum vulgare – USES Culinary purposesUsed in medicine as a flavouringCarminative
120CARAWAY & CARAWAY OILDEFINITION: Caraway consists of the dried, ripe fruits of Caram carvi (Umbelliferae).GEOGRAPHICAL SOURCESWild & Cultivated in Central & Northern Europe, Holland, Denmark, Germany, Russia, Finland, Poland, Hungary, Britain, Egypt, Morocco, Australia & China
121MACROSCOPICAL FEATURES A biennial herb growing up to 1 m in height.Herb: Normally consists of mericarps separated from the pedicels. Fruits are slightly curved, brown & glabrous.Size: 4-7 mm long, 1-3 mm wideOften the stigma & style are still attached.Characteristic aromatic odour & taste
122MICROSCOPICAL FEATURES Pitted sclerenchymasecretory canalsDark, red-brown cells containing a pale yellow or colourless oleoresinThick cellulose wallsCalcium oxalate crystals
124CORIANDER & CORIANDER OIL DEFINITION: Coriander is the dried, nearly ripe fruit of Coriandrum sativum (Umbelliferae).GEOGRAPHICAL SOURCESIndigenous to Italy. Also cultivated in Holland, Central & Eastern Europe, Mediterranean (Morocco, Malta & Egypt), China, India & Bagladesh.
125MACROSCOPICAL FEATURES Annual herb growing 0.7 m in height with white or pink flowers.Drug: Normally consists of whole cremocarps – straw yellow & 2-4 mm in diameter when ripe.Considerable variation occurs (e.g. Indian variety > oval).Apex has 2 styles.Fruits have an aromatic odour & spicy taste.Unripe plant: unpleasant mousy odour same odour oil has when made from unripe fruit.
126MICROSCOPICAL FEATURES Outer pericarp: stomata & calcium oxalte prisms.Thick sclerenchymaTesta:= brown flattened cellsEndosperm is curved & consists of parenchymous cells containing fixed oils.
129PEPPERMINT & PEPPERMINT OIL DEFINITION: Peppermint is the dried leaves of Mentha piperita (Labiate). It should contain at least 1.2 % volatile oil.GEOGRAPHICAL SOURCES:Europe & America
130MACROSCOPICAL FEATURES All mints have a square stem & creeping rhizome.Black mint, which is the most commonly cultivated variety in England, has purple stems and dark green petiolate leaves tinged with purple. Leaf blades are 3-9 cm long with a grooved petiolate up to 1 cm long.Pinnate venation.Glandular trichomes: bright yellow points (hand lens)Small purple flowers appear in late summer.
131MICROSCOPIC FEATURES Diacytic stomata Multicellular clothing trichomes 2 types of glandular trichomes (one with a unicellar head; with a multicellular head).Calcium oxalate is absent.
132Oleum MenthaeOil of peppermint is obtained from Mentha piperita via steam distillation using the flowering tops.Oil should contain at least 44 % menthol, & menthone and % menthyl acetate.