Transcript Evaluation of plant drugs:

S1 L2 Evaluation of plant drugs
1. Botanical
A. Macroscopy
Anna Drew
Evaluation of plant materials
• Eg for pharmacopoeial purposes
• 1. Botanically
• 2. Chemically
• 3. Biologically
• Often need the combination of all 3
1. Botanically
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Authentication of material
Genus – species – botanist – family
Eg Cinnamomum verum J.S.Presl.
(Vernacular name: ‘kurundu’ etc)
(Common name: Cinnamon)
(Latin name: Cortex Cinnamomi Ceylanici)
Part of the plant Dried inner bark of the shoots grown on cut
stock or trunk bark
Description
• Sensory characters
• Colour, odour, taste
• Macroscopical
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Fibrous etc
Rarely get whole plant to identify
Organ may be fragmented
Only part of plant may be sent
• Microscopical
• Sections (transverse, longitudinal etc)
• Soften – maceration – 5%KOH first
• Depigmentation to see – chloral hydrate etc
2. Chemically
• Quantitative
• Need to develop assay
» Titration
» Coloured derivative spectroscopy
» Chromatography – more specific
• Ash value
• H2O content
• Qualitative
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Extractive value – certain weight plant material
Volatile oil – steam distillation
Tannins – complex with skin – heat with hide powder
Saponins – froth with beer – haemolyses red blood cells
• 3. Biological
• Assay to measure active ingredient
• Ethical?
• 1. BOTANICAL aspects
• Identification of plant material
» Essential to recognise diagnostic structures
• Quality assurance
• A. Macroscopy
• Naked eye
• Hand lens
Diagnostic structures
• Living plant may include one or more:
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Leaf
Flower
Fruit
Seed
Stem
Bark
Root
Rhizome (underground stem)
The "Typical" Plant Body The Root
System
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The "Typical" Plant Body The Root System
Underground (usually)
Anchor the plant in the soil
Absorb water and nutrients
Conduct water and nutrients
Food Storage
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The Shoot System
Above ground (usually)
Elevates the plant above the soil
Many functions including:
– photosynthesis
– reproduction & dispersal
– food and water conduction
• Note: the shoot system includes the leaves & reproductive organs
Leaves
• Appendages to stem
• blade / lamina
• petiole (stalk)
• Wide variety of external features
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leaf or leaflet
simple or compound
shape
apex
margin
base
petiole
venation
vein angle
texture
size
[i] Composition
[ii] Size
Measure length and breadth of several leaves, leaflets
and record a range of sizes
[iv] Apex
[vi] Base:
sessile (no stalk) or petiolate (stalk)
lamina equal or unequal at base
[vii] Surface
• Adaxial (upper) and abaxial (lower) leaf surfaces
may vary and differ from each other
• Pubescent – leaf hairs and trichomes
• Glaborous – smooth
• Other specialised features - oil ducts
• Venation parallel, pinnate, reticulate
• Midrib / veins prominent , depressed
• Number and angle of lateral veins
• If lateral veins run straight to margin, divide or
anastomose
Flowers
• Indeterminate or racemose
• Central axis from which pedicels arise
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Raceme
Corymb
Spike
Umbel
Head
Panicle
• Determinate or cymose
• Central bud becomes flower, no further growth possible
» Diachasium
» Sympodial cyme
Barks
• Shape in commerce
• Flats, curved, channel,
• quill, double quill, compound quill
• Epiphyte tissue on outer surface
• Lichen, moss, liverwort
• Outer surface
• Colour, texture, lenticels, cracks
• Inner surface
• Colour markings
• Fracture
• Fibrous, starchy
Roots & Rhizomes
• Shape, size, colour
• Surface markings
• Transverse surface markings
• Roots have rootlet scars
• Solid xylem core
• Rhizomes have central pith, scale leaves, buds
Seeds
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Shape
Size
Colour
Surface markings
Micropyle (hole in seed coat)
Hilum (funicular scar on seed coat)
Raphe (ridge formed from fused funiculas)
Aril (outgrowth from hilum)
Caruncle (outgrowth from micropyle)
Strophiole (outgrowth from raphe)
Wings
Plumes
Fruits
• Wide variety
• Dry fruits
» Eg cremocarps (Umbelliferae)
» Eg legumes (Senna)
» Eg capsules (Poppy)
• Succulent fruits
» Eg drupes (Olive)
» Eg berries (orange, Solanaceae fruits)
» Etc
• 2 mericarps each with seed = 1 cremocarp
» Eg coriander
Pericarp
3 layers
- development of ovary wall
- epicarp (outer epidermis)
- endocarp (inner with modified layers)
- mesocarp , succulent, pithy, spongy
parenchyma
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Separate mericarps or entire cremocarps
Shape from lateral and dorsal views
Stylopod
Number of primary ridges
Any secondary ridges
Colour
Size