Terpenoids Flashcards
terpenoids are also known as
isoprenoids
terpenoids are produced from acetyl coenzyme A using which metabolic pathway
mevalonic acid
most important groups of terpenoids include
sesquiterpenoids (C15)and monoterpenoids (C10)
sesquiterpenes and monoterpenes often used as (3)
- flavoring agents or in perfumes
- monoterpenes active constituents in oral products and disinfectants
- sequiterpene lactones - anti-cancer agents
volatile monoterpenes and sesquiterpenes are derived from
volatile oils extracted from plants
terpenoids in nature occur as
complex volatile oil mixtures
terpenoids are isolated from (5)
- specialized oil cells
- oil cavities - schizogenous or lysigenous
- glandular hairs - libiatae
- modified parenchyma cells
- oil tubes
in conifers oil is produced in which tissues
all tissues
the structural variation of terpenoids is due to
different folding patters or cyclization
terpenoid oils that occur in nature are a complex mixture of
- hydrocarbons and oygenated terpenoid derivatives
volatile oils are classifed according to the nature of the
terpenoid constituent
name the terpenoid consituent for each oil name below:
- hydrocarbon containing (Turpentine)
- alcohols (monoterpenes) - Corriander & Geranium
- aldehydes (mono terpenes) - lemon grass
- ketones (monoterpenes) - spearmint
- ethers (monoterpenes) -eucalyptus
- Turpentine - pinenes; camphene
- Corriander & Geranium - linalol; geraniol
- lemon grass - cintronellal, citral
- spearmint - carvone
- eucalyptus - cineole
how are terpenoids extracted
- primarily distallation
what doe the extraction method selection depend upon (3)
- nature of plant material
- location of oil producing cells
- stability of oil being extracted
what are the methods of extraction of terpenoids (6)
- hydrodistillation
- expression
- enfleurage
- solvent extraction
- destructive distillation
- liquid CO2
what are the 3 methods of distillation in hydrodistillation and what are each best suited for
- water distillation
- non-heat labile; dried plants
- water & steam distillation
- heat labile, fresh or dried plants
- steam distillation
- fresh plants
describe the water distillation process, what is it used for
- extraction of terpentine from wood sources
- non-heat labile i.e. those not damaged by boiling
- dried plant materials
- e.g. terpentine
- Process
- dried plants placed in distillation chamber
- heated to boiling
- volatile oil and water condenses in condensing chamber
- separate oil/water fractions
describe the water/steam distillation process and what it is used for
used for
- fresh or dry materials
- can be used with heat labile oils
- e.g. clove oil
process
- finely ground plant materials added to chamber
- covered with water
- steam piped in
- volatile oil carried by steam to condensing chamber
- separate water/oil layers
describe the steam distillation process and what it is used for
Uses
- fresh plants
- e.g. spearmint peppermint
Process
- macerate plants place on perforated trays or wire baskets
- steam forced through plant
- oils carried up in steam into receiving chamber
- separate oil/water layer
the expression process is useful for this type of oils, why
- heat labile e.g. citrus oils
- no heat applied, oil glands in fruit peel
describe the expression process
- oil glands in fruit peel pierced by projections then rolled through a mill which extracts oils
- water spray removes oil from peels
- oil separated from water by centrifugation
enfleurage is commonly used in this industry
describe the process
- perfume
- removal of oils from petals
process
- oil from flower petals extracted into cold fat or fixed oils
- petals placed on glass plates covered with cold fat or fixed oils
- after period of time petals replaced
- once fat/oil has absorbed as much oil as possible it is extracted with alcohol
- the alcohol extract is used in perfume
- the oil is concentrated form by evaporation of alcohol
what is a modified enfleurage method of extraction, describe the process
- pneumatic method
- warm air is passed through the petals, oil picked up into air
- oil laden air sprayed with spray of melted fat
- oil separated from fat via alcohol extraction
alternate
heat flowers in hot fat to extract oil, filter then cool
solvent extraction method involves the use of_________and what is an advantage
- low boiling point solvents (benzene) to extract the oil
- more natural oil scent due to lower temperature than distillation
destructive distillation is used for the extraction of these oils
describe the process
- pine oils , wood resin e.g. pine tar
Process
- heat plant in absence of water
- plant decomposes and liberated volatile oil
- condensed volatile oil collected in chamber where separated into 2 layers
- remaining plant material carbonized
the CO2 method of extraction is used for _____ and offers these advantages
- low molecular weight species of terpenoid oils
- good recovery, as no heat, can be used with all types of oils
describe the CO2 extraction process
- liquify gas under pressue
- introduced into vessel containing plant material
- CO2 carries volatile oil into reservoir
- CO2 is vaporized, oil left behind
what are the most important clinical applications of monoterpenes (4) and sesquiterpenes (3)
- monoterpenes
- anthelmintic
- disinfectant
- irritant
- sedative
- sesquiterpenes
- analeptic agent
- antibiotic
- anthelmintic
monoterpenoids such as ___6_____are still used in disinfectants and antiseptic agents.
- thymol
- menthol
- geraniol
- citronellal
- citral
- carvone
which two terpenoids are used as antiseptics in oral preparations e.g. mouthwash & toothpaste
- thymol
- carvacol
name a use of terpenoids in anthelmintic and or as an insecticidal
e.g. citronella
how do terpenoids work as irritants, provide example
- camphor used as irritant
- rubefacient, irritates skin turns red, but the produces localized anesthetic effect
terpenoids can act on the CNS and cause the following effects (3)
- central stimulating
- central sedating
- central narcotic
what is a terpenoid that has:
a central stimulating effect
a central sedative effect
- a central stimulating effect
- camphor
- a central sedative effect
- valerian
what is a carminative
relieves gas
e.g. ginger, peppermint
feverfew is a sesquiterpene lactone used for
migraines and arthritis
rowachol is a monoterpene used in relief of
gall stones
peppermint has been used in treatment of
IBS
why is the quality control of terpenoids difficult (3)
- because the molecules are complex in nature
- seasonal variation in oil production
- batch to batch consistency is difficult
what are 3 ways in which standardization of terpenoids can be achieved
- physicochemical methods
- chromatographic analysis
- spectroscopic analysis
physicochemical methods for anlysis of terpenoids include (7)
- freezing point
- optical rotation
- refractive index
- solubility in alcohol
- total alcohol ocncentration
- total esters
- nonvolatile residue
which terpenoid is not assessed for optical rotation
turpentine
why are physicochemical methods alone not suitable for standardization of terpenoids
adulteration methods have become sophisticated therefore orthoganal approach is best
chromatographic methods used in the standardization of terpenoids include (3), when is each used
- TLC
- during characterization
- GC
- during characterization with TLC, then routinely GC
- good for qualitative and quantitative
- get fingerprint
- HPLC
- for complex oils where overlapping peaks present
- after GC using fractions
spectroscopic methods for standardization of terpenoids include
- mass spec coupled with GC or HPLC
