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Which type of secretory structure is associated with ginger?
Which type of secretory structure is associated with ginger?
What is one method used for isolating plant resins?
What is one method used for isolating plant resins?
Which identification test involves examining properties such as solubility and taste?
Which identification test involves examining properties such as solubility and taste?
Which therapeutic effect is associated with the resin types jalap and ipomea?
Which therapeutic effect is associated with the resin types jalap and ipomea?
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What type of acid can be identified through a specific chemical test for resins?
What type of acid can be identified through a specific chemical test for resins?
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Which method is NOT used for isolating terpenoids?
Which method is NOT used for isolating terpenoids?
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What indicates the presence of terpenoids in an identification test?
What indicates the presence of terpenoids in an identification test?
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Which of the following therapeutic effects is NOT attributed to terpenoids?
Which of the following therapeutic effects is NOT attributed to terpenoids?
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In the enfleurage process, how are the essential oils extracted from flowers?
In the enfleurage process, how are the essential oils extracted from flowers?
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Which best describes glycosides?
Which best describes glycosides?
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What is the primary role of glucose in glycosides?
What is the primary role of glucose in glycosides?
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What is the initial step in the isolation of glycosides from plant material?
What is the initial step in the isolation of glycosides from plant material?
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Which plant-derived substance is specifically noted for use in cancer treatment?
Which plant-derived substance is specifically noted for use in cancer treatment?
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What does the presence of a brown ring at the interface during the identification test indicate?
What does the presence of a brown ring at the interface during the identification test indicate?
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What is the initial solvent used to extract alkaloids from the dried and powdered plant material?
What is the initial solvent used to extract alkaloids from the dried and powdered plant material?
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What role do glycosides play in pharmaceutical applications?
What role do glycosides play in pharmaceutical applications?
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Which of the following plants is known to have a high occurrence of alkaloids?
Which of the following plants is known to have a high occurrence of alkaloids?
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What component remains in the aqueous layer after precipitating alkaloids using the ethyl acetate solvent?
What component remains in the aqueous layer after precipitating alkaloids using the ethyl acetate solvent?
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What is used to purify isolated glycosides after their initial extraction?
What is used to purify isolated glycosides after their initial extraction?
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In which way do alkaloids primarily appear in plants?
In which way do alkaloids primarily appear in plants?
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What therapeutic effects do glycosides have in animals?
What therapeutic effects do glycosides have in animals?
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What method is used to extract citrus oils?
What method is used to extract citrus oils?
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Which of the following is NOT a therapeutic application of eucalyptus oil?
Which of the following is NOT a therapeutic application of eucalyptus oil?
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What is evaluated in the physical test for volatile oils?
What is evaluated in the physical test for volatile oils?
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What type of resin is produced in plants as a response to injury?
What type of resin is produced in plants as a response to injury?
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Which of the following tests is NOT used for identification of volatile oils?
Which of the following tests is NOT used for identification of volatile oils?
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Which essential oil is mentioned as having a relative density between 1.030 and 1.063?
Which essential oil is mentioned as having a relative density between 1.030 and 1.063?
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What is a characteristic of physiological resins?
What is a characteristic of physiological resins?
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Which of the following is a method used to check the purity of essential oils?
Which of the following is a method used to check the purity of essential oils?
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What color indicates the presence of tannins when ferric chloride is added to a boiled sample?
What color indicates the presence of tannins when ferric chloride is added to a boiled sample?
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Which method is used for isolating volatile oils from plants that are not damaged by boiling?
Which method is used for isolating volatile oils from plants that are not damaged by boiling?
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Condensed tannins should not be used as a standard for the determination of which type of tannins in plant extracts?
Condensed tannins should not be used as a standard for the determination of which type of tannins in plant extracts?
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What is a primary therapeutic effect of tannins?
What is a primary therapeutic effect of tannins?
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In which plants are volatile oils commonly found?
In which plants are volatile oils commonly found?
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Which of the following methods is used for extracting volatile oils from substances that would be damaged by direct heat?
Which of the following methods is used for extracting volatile oils from substances that would be damaged by direct heat?
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What role do tannins have in treating diarrhoea and stopping small hemorrhages?
What role do tannins have in treating diarrhoea and stopping small hemorrhages?
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Which type of tannins would have similar biological activity to those present in plant leaves?
Which type of tannins would have similar biological activity to those present in plant leaves?
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Study Notes
Plant Sources of Resins
- Ginger contains resin cells.
- Pine wood secretes resin through schizogenous ducts.
- Cannabis contains glandular hairs.
Isolation of Resins
- Alcohol extraction followed by water precipitation is used to isolate resins from plants such as jalap, ipomea, podophyllum.
- Distillation is used to separate oils, like colophony.
- Heating plant parts is a method for isolating resins, exemplified by guaum.
- Incisions are made to obtain resins from plants like asfoetida and balsams.
- Processing incrustation is used to isolate shellac.
Identification of Resins
- Physical tests: Examine solubility, taste, odor, and powder appearance under a microscope.
- Chemical tests: Determine acid value, iodine value, and saponification value.
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Specific chemical tests:
- Cinnamic acid
- Benzoic acid and benzoin
- Tolu balsam
- Peru balsam
Therapeutic Effects of Resins
- Local irritant and act as local cathartic: Examples include jalap and ipomea.
- Anti-cancer: Podophyllum is used in this way.
- Bronchial asthma: Cannabin can be helpful.
- Tinctures: Benzoin is used in tinctures.
- Ointments and plasters: Turpentine and colophony are used in these formulations.
- Production of emulsions.
Terpenoids
Occurrence
- Terpenoids are naturally occurring chemicals found in various plant parts: leaves, stem, bark, roots, flowers.
- Present in essential/volatile oils: Examples include oleoresin, ovinine, ergotamine.
Isolation
- Steam distillation: A process where a liquid inner current of steam is used to purify non-volatile liquids immiscible with water.
- Solvent extraction: A technique that involves the partial removal of a substance from a solution mixture by dissolving it in another immiscible solvent.
- Enfleurage process: Used to extract essential oils and perfumes from flowers using colourless animal or vegetable fats.
Identification
- A greyish color develops when 2 ml of an organic extract dissolved in 2 ml of CHCl3 is evaporated to dryness and then 2 ml of concentrated H2SO4 is added and heated for 2 minutes. This indicates the presence of terpenoids.
Therapeutic Effects
- Terpenoids have been found to have potential benefits in preventing and treating various diseases and cancer.
- Anti-microbial
- Anti-fungal
- Anti-parasitic
- Anti-viral
- Anti-allergic
Glycosides
- Definition: Glycosides are composed of a sugar (glycon) and a non-sugar component (aglycon). Glucose, the sugar component, increases the solubility and bioavailability of the sample.
Occurrence
- Glycosides are predominantly found in plants and animal tissue: Examples include digitalis, Apocyanaceae, Aracideae, Legumanceae.
Isolation
- The dried plant material is ground into a coarse powder.
- The powder is extracted with aqueous ethanol using a Soxhlet apparatus.
- Non-glycosidal impurities are removed by precipitation with lead acetate solution.
- Excess lead acetate is removed by passing H2S gas through the extract, precipitating lead sulfide which is then filtered out.
- The filtrate contains the glycosides, which can be obtained by removing the solvent under reduced pressure.
- Column chromatography is used for further purification.
Identification
- A brown ring forms at the interface when 5 ml of plant extract is treated with 2 ml of glacial acetic acid containing 1 drop of ferric chloride solution, then layered with 1 ml of concentrated H2SO4. This indicates the presence of carotenoids. A violet ring may appear below the brown ring in the acetic acid layer, and a greenish ring may gradually develop throughout the third layer.
Therapeutic Effects
- Plants: Regularity function, protective function, sanitary function.
- Animals: Cardioactive, local irritant in function.
- Used in the synthesis of steroidal diuretics, coffee, tea, sex hormones, and oral contraceptives.
Pharmaceutical Applications
- Flavoring agent
- Coloring agent
- Carrier for drugs and medicines
Alkaloids
Occurrence
- Alkaloids are found in approximately 90% of plants, particularly in families such as Rubiaceae, Asteraceae, Papaveraceae.
- They are also present in fungi, Pteridophytes, Gymnosperms.
- Crystalline substances are common.
Isolation
- The dried and powdered plant material is first extracted with petroleum ether or hexane to remove fats, oils, terpenes, and wax.
- The material is then subjected to an alcohol extract using methanol or ethanol.
- The extract is evaporated to leave a crude alkaloid mixture.
- This mixture is then precipitated with a dilute aqueous tartaric acid solution and ethyl acetate.
- The** ethyl acetate layer** contains neutral and weakly basic alkaloids. The solvent is evaporated to isolate these alkaloids.
- The aqueous layer is neutralized with ammonia or sodium carbonate and extracted again with ethyl acetate. The organic layer will then contain basic alkaloids, while the aqueous layer will contain quaternary ammonia ions.
Identification
- Similar to the glycosides, alkaloids can be identified by treating 5 ml of plant extract with 2 ml of glacial acetic acid containing 1 drop of ferric chloride solution followed by layering with 1 ml of concentrated H2SO4. A brown ring at the interface will indicate the presence of carotenoids.
Tannins
Occurrence
- Tannins are found in oak, hemlock trees, and legumes: Examples include hallo-tannins and condensed tannins.
Identification
- Boil 0.5 g of dried powdered sample in 20 ml of water in a test tube, filter, and add a few drops of ferric chloride. Observe the color change. A brownish-green to blue-black coloration indicates the presence of tannins.
Isolation
- Condensed tannins: The tannin preparation should not be used as a standard for determining condensed tannins in plant extracts as it is a mixture of condensed and hydrolyzable tannins. The biological activity of the isolated tannins should closely resemble those found in the leaves.
Pharmaceutical Application
- Plants containing tannins have astringent, homeostatic, and antiseptic properties.
- Used to control diarrhea and stop small hemorrhages.
Therapeutic Effects
- Bind to protein enzymes
- Block digestion
- Antioxidants
Volatile Oils
Occurrence
- Volatile oils are the odorous, volatile principles found in plant and animal sources.
- They are lighter than air, critically active, have a high refractive index, and possess distinctive odors.
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Secretory structures:
- Glandular hairs in Labiatae
- Modified parenchyma cells in Piperaceae
- Special tubes or oil tubes in the pericarp of fruits in Umbelliferae
- Lysogenous and Schizogenous cavities in Rutaceae
- Conifers can contain volatile oils in all tissues.
- Petals of roses
- Bark of cinnamon
- Fruits of coriander
- Leaves of peppermint
Isolation
- Distillation by Water: Used for plants that are not damaged by boiling. Example: Turpentine oil
- Water and Steam Distillation: A method for substances sensitive to direct heat. Examples: clove and cinnamon.
- Destructive Distillation Without Air (Vacuum): Suitable for tough materials like barks, seeds, and roots. Example: Members of Pinaceae.
- Ecuelle Method: Used for extracting citrus oils by mechanically rupturing oil cells in the rind using pointed projections.
Therapeutic Applications
- Counter irritant
- Eucalyptus oil as an inhalant
- Improves local circulation
- Carminative and shows anti-spasmodic effects
- Thymol is used in mouthwashes and gargles.
- Local anesthetic
- Reduces lung secretions in cough and asthma
- Antiseptic, antibacterial, antifungal
- Anti-helminthic
- Used in aromatherapy (lavender, rosemary)
Identification
- Physical test: Determine relative density, refractive index, optical rotation, freezing points, etc.
- Chemical test: Includes acid value and peroxide value.
- Chromatographic methods: Thin layer chromatography and gas-liquid chromatography (GLC) are used to check the purity and composition of essential oils and detect impurities.
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Description
Explore the fascinating world of plant resins in this quiz. Learn about various sources such as ginger and pine, methods of isolation like alcohol extraction and distillation, and the techniques used for their identification. Test your knowledge on the chemistry and applications of resins derived from plants.
