Terpenes, Volatile oils and other compunds Flashcards
Volatile oils also referred to as
ethereal’ and ‘essential oils
___________will evaporate into the atmosphere if left exposed.
volatile oils (cf. Fixed oils)
State the characteristics of essential oils /Volatile oils
They are generally complex mixtures
Have an associated smell (useful for identification)
Are often optically active
Have a high refractive index
Not very soluble in water but soluble in organic solvents,
They are prone to oxidation (colour change).
List types of compounds present in Volatile oils
Terpenoids(mainly monoterpenes)
Phenylpropane compounds,
Simple alcohols (methanol, ethanol)
and occasionally any one of the major compounds as a glycoside (linkage to a sugar)
_____________form one of the largest groups of compounds, occurring in plants, animals and insects, and many other organisms.
Terpenoids
Functions of Terpenoids are still not realised for most of the compounds
____________have hormonal function
_________ have antioxidant function
__________ possess antibacterial and antifungal activity
some ___________ occurring in plants have deterrent properties
Sterols
Carotenoids
Sesquiterpenes
terpenes
What are terpenes?
and isoprene units are made of?
These are composed of isoprene units (derived from acetylCoA molecules) condensed together under enzymatic control.
An isoprene unit is a branched five-carbon unit (C5H8).
Mention the four(4) main groups of Terpenoids
Monoterpenes
Sesquiterpenes
Diterpenes
Triterpenes
A compound that contains two isoprene units is known as
Monoterpenes C10H16
A compound composed of three(3) isoprene units
Sesquiterpenes (C15H24)
A compound composed of four(4) isoprene units
Diterpenes (C20H32)
A compound composed of six(6) isoprene units is called
Triterpenes
List the different types of reaction that increase the range of terpenoids compound
N/B: _____________present will influence the compounds that will exist in plant
Cyclization and Oxidation reactions
N/B: The type of reaction present will influence the compounds that will exist in plant
The structure of monoterpenes found in volatile oils may be ______________
linear, monocyclic, or bicyclic.
Facts about Geraniol ( hint it is present in 7 things) (has 3 agents)
Geraniol is ___________
Geraniol is an important constituent of essential oil of ginger, lemon, lime, lavender, nutmeg, orange and rose. It has been reported to have cytoprotective, antioxidative and anti-carcinogenic agent.
Geraniol is an example of Linear Monoterpenes
Eucalyptus oil is a volatile oil used for……..
Inhalation/decongestion
What is the therapeautic use of Peppermint?
Carminative
What is the therapeautic use of Begarmot/Cinnamon?
Flavouring
What is the therapeutic use of Clove?
Tooth Tincture/Antiseptic
What is winter green used for ?
Analgesic
What is Rose/Lavender used for
Perfumery/Cosmetics
What are Phenylproprane compounds?
Nine(9) carbon-based compounds that have an aromatic ring
The biosynthesis of Phenylproprane compounds is from ……….
Shikimic acid
State the two main methods of extracting oil from it plant source
- Distillation(Two main types of distillation processes are used.)
- Water distillation – Boiling the plant material in water. The water vapour and the oil condense separately. The oil forms a layer on the water and is then collected. Cannot be used for oils that decompose easily.
- Steam distillation – The plant material, suspended in a basket, is treated with steam. The oil is recovered at a lower temperature (< 100 oC) than its boiling point (usually in excess of 200 oC) by this method. Can only be used where significant amounts of oil are present and if the oil is not easily oxidised/hydrolysed. (See handout on Moodle for diagram of apparatus and collecting vessels for oils lighter and heavier than water.)
(Note: Some oils are glycosides and these need to be hydrolysed [enzymatically or using mineral acid] before under taking distillation.)
- Expression (Pressure): This is a process by which oils are obtained by applying pressure (e.g. lemon oil BP). Machines called ‘sfumatrice machines’ are available but the quality of the oil is inferior to that produced by the ‘hand method’. With the latter method there is very little contact with the albedo layer, which contains enzymes that can degrade the oil.