Botany Lecture 4

1 Spring Semester 2013

Botany and Medicinal Plants

Department of Pharmacognosy Prof. Nahla Ayoub Lecture (4)

cell cONTeNT NaTural MeTabOliTes

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Types of Natural Metabolites: A) Primary metabolites: Carbohydrates.

Amino acids (Protein).

Fats.

Function: Participate in cellular activities & used as precursor for the biosynthesis of 2° metabolites.

Distribution: Distributed universally throughout the plant kingdom.

B)Secondary metabolites:

Represent the majority of natural products e.g., alkaloids, glycosides, tannins, volatile oils, steroids ... etc.

Have a restricted distribution (perhaps only found in certain species, genus & family ... etc.).

Function: Are not clear, may or may not be essential.

The cell cONTeNTs

I-Primary Plant Metabolites

II- Products of Metabolism

A-Carbohydrates (Starch)

B- Proteins

C- Fixed oil & fats

i-Crystals

II- Gums, Mucilages & pectins

III- Resins & Resin Combination IV- Tannins

V- Volatile oils VI- Alkaloids

VII- Glycosides VIII- Antibiotics

IX- Aflatoxins X- Vitamins

XI-Hormones XII- Enzymes

FOOd sTOrage prOducTs priMary plaNT MeTabOliTes

A- Starch As granules in all storage organs e.g. roots rhizomes and seeds. The major sources of starch intake worldwide are the cereals (rice, wheat, and maize) and the root vegetables (potatoes) Starch is a polysaccharides of high molecular weight ( polymer of Alphaα-glucose and formed during photosynthesis) . Detection It gives blue color with iodine.

Potato Starch

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uses OF sTarch

Adjuncts in tablet formulation: diluents, binder,

desintegrants, anti-caking agents

Food technology, paper production, textile industry,

glues, adhesives .

Dusting powder for cosmetic preparation.

As lubricant and in treatment of iodine poisoning.

As indicator for the iodine titration.

Drugs derived from starch.

Potato starch grains (viewed under high power)

Maize starch grains (viewed under high power)

Rice Starch grains

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B- Proteins As aleurone grains (storage and source of proteins ) in seeds.

It is composed of a large number of amino acids united by peptide linkage. They are complex nitrogenous organic substances of high molecular weight. It composed from Matrix, globoids and crystalloid

Detection It gives red color with Millon’s reagent.

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Aleurone grains: composed from Matrix, globoids and crystalloid

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The aleurone layer of the seed lies between the outer pericarp and the inner starchy endosperm.

Aleurone grains

Pericarp

Aleurone Endosperm (Starchy)

Oil drops

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C- Fixed oil and fats Found in seeds Reserve fats occur as crystalline masses or oil drops (endosperm ) Detection Sudan III red color They are used pharmaceutically in • Soaps, liniment and plaster. • Stimulant cathartic (castor seed oil).

• Solvent for IM. Injection (in steroidal drugs).

e.g. peanut, cotton seed, sesame and corn oils.

• In treatment of hypercholesteremia e.g. olive oil.

by-prOducTs OF MeTabOlisM I-Crystals

A- CALCIUM OXALATE

1- Prisms 2- Rosette and cluster Cluster: Numerous prisms or pyramids or both grown together to form spherical masses with projecting point

Rosette : Crystals having a

large center from which crystal radiate,

appear to have a toothed circumference.

e.g. in aleurone grains of Umbelleferae.

Crystals may be reserve or waste products of cellular activity. Calcium salt in the soil + oxalic acid (metabolism of carbohydrate)

e. Rhubab rhizome

e.g. Hyoscyamus

( long prism) e.g.in Quillaia bark

3- Needles (acicular) 4--Microcrystal or sandy crystal

commonly occur in bundles (raphides) e.g. Squill

Very small, e.g. in belladonna leaf (microsphenoidal) and cinchona bark (microprismatic).

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Forms of CALCIUM OXALATE

1- Prisms

3-Rosette

2-Cluster

5-Microcrystal or sandy crystal

4-Needles (acicular)

Rosette

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Special arrangement of Ca Ox

Crystal sheath [Senna, Cascara] Crystal layer

(Stramonium)

e.g. Quillaia e.g. Rhubarb

e.g. Squill e.g. Hyoscyamus

calciuM OxalaTe crysTals

Rosette

e.g. Senna in aleurone grains of Umbelleferae.

Raphides

e.g. Stramonium e.g. Belladonna

e.g. Squill

Rosette

in aleurone grains of Umbelleferae.

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Atropa belladonna vein islet Idioblasts

Datura stramonium vein islet Crystal layer

b- calciuM carbONaTe:

Cystolith hair of Cannabis sativa

Identified by effervescence with dil. HCl.

c- silica: Skeleton of diatoms

(kieselguhr).

Sclerenchymatous layer of cardamom seed.

Calcium carbonate deposit

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aNTibiOTics Compounds synthesized

by certain molds and fungi

Having bacteriostatic activity.

e.g. Penicillin and tetracycline.

aFlaTOxiNs Mycotoxins developed by mouldy grains

Cause serious reaction

They are potent carcinogen, and mutagen.

e.g. Aflatoxin B1, G1 developed by Aspergillus.

ViTaMiNs - Organic compound necessary to the normal

growth and maintenance of life in animals including human.

- Isolated from plant or animal purified and concentrated for use as drugs e.g. (Ascorbic acid)

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hOrMONes Active hormones

secreted by the endocrine glands.

They control the growth, development and metabolism in various ways. e.g . Auxins, Cytokinins.

eNzyMes Organic bio-catalysts

produced by living cells.

They make most of the chemical reactions which make up life processes e.g. Amylase, Protease, Lipase