Carbohydrates and natural products unit 3

What is a natural product?

A substance obtained from an organic or natural source.

What are the major uses of natural products?

-They are used as drugs for the treatment of a wide range of diseases, eg. Morphine, atropine, digoxin,

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-pharmaceutical aids ie: Suspending & emulsifying agents, suppository bases, binders, excipients, sweetening & colouring agents

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-cosmetics as flavouring & colouring agents

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-Food industries: as dusting powders, as indicators and in perfumery

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-culture media for the propagation of microorganisms in microbiology laboratories & biotechnology.

What are crude drugs?

-Any unrefined natural substance derived from plant, animal, mineral or microbial sources that has only undergone basic processes such as collection, drying and size reduction without artificial modification.

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-Harvested and usually dried plant or animal sources of medicinally useful products before extensive processing or modification.

What are the three kingdoms from which crude drugs are derived?

Mineral; vegetable; and animal kingdoms.

Egs of Animal crude drugs

Mentha, Lobelia, Cantharidis, Cochineal

Egs of Crude drugs from entire organs of plants or animals

Senna, Clove, Fennel, Linseed, Quassia, Cinchona, Liquorice, Thyroid gland.

Mineral rude dugs

chalk, kaolin, talc

Organized drugs as egs of crude drugs

fruit, seeds, root, leaves

What are the three types of drugs derived from plants?

-Herbal drug:

Derived from specific parts of medicinal plants (roots, bark, leaves & flowers) ie: Senna

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-Compounds isolated from nature:

specific natural entities extracted, purified and separated from natural sources ie: Morphine isolated from opium poppy, Digoxin fox glove plant

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-Nutraceuticals or functional foods:

Components derived from foods for medicinal benefits

ie: Lycopene found in tomoatoes , Omega-3-Fatty acids from flax or Chia seeds

What is an official drug compared with an unofficial drug?

An official drug is recognized and described as a therapeutic agent in a pharmacopoeia; an unofficial drug is not recognized in the pharmacopoeia but is used therapeutically.

What factors affect the potency of bioactive substances in crude drugs? (mind map)

-Time of the year (seasonal varieties)

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-Time of the day.

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-Stage of maturity and age.

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-Plant Organs

When are different plant organs collected?

-Flowers are collected in dry weather;

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- leaves when the plant is flowering;

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-fruits and seeds when fully mature but unripe;

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-underground organs when aerial parts die down

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- bark in spring

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-Unorganized drugs in dry weather

What is evaluation of crude drugs?

The process of identifying and determining the quality; safety; and purity of a crude drug.

What are the four methods of evaluating crude drugs?

Organoleptic; microscopic; chemical; and physical evaluation.

What is organoleptic evaluation?

Evaluation using the organs of sense including macroscopic appearance; odour; taste; and feel.

What macroscopic characteristics are assessed during organoleptic evaluation?

Shape and size; colour and external markings; fracture and internal colour; odour; and taste.

What are chemical and physical evaluation used for?

Chemical evaluation identifies drugs and determines purity and potency; physical evaluation uses properties such as specific gravity; solubility; optical rotation; and melting point.

What are the major plant organs used as crude drugs?

Aerial parts or herb

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- leaf(folia)

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-flower (flos)

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fruit fructus)

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-bark (cortex)

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- root (radix)

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- rhizome (rhizoma)

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- bulb (bulbus)

What are carbohydrates?

Compounds composed of carbon; hydrogen; and oxygen that are produced by photosynthesis and serve as a major source of dietary energy.

What are the main dietary sources of carbohydrates?

Rice; maize; wheat; potato; and arrowroot.

What are carbohydrates also called and what are their main structural features?

They are called saccharides or sugars; they are aldehydes or ketones containing many hydroxyl groups.

What is the difference between glucose and glycogen?

-Glucose provides immediate energy while glycogen is stored glucose that serves as reserve energy

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-Glucose provides energy for the brain and ½ of energy for muscles and tissues

How are carbohydrates classified?

They are classified into simple carbohydrates such as monosaccharides and disaccharides; and complex carbohydrates such as starch; glycogen; and cellulose.

What are monosaccharides and disaccharides?

Monosaccharides are single sugar units; disaccharides contain two covalently linked monosaccharides.

What are oligosaccharides and polysaccharides?

Oligosaccharides contain a few linked monosaccharides; polysaccharides are polymers made of long chains of sugar units.

What are the main monosaccharides discussed?

Glucose; fructose; and galactose.

How are monosaccharides classified according to carbon number?

Three-carbon sugars are trioses; four-carbon sugars are tetroses; five-carbon sugars are pentoses; and six-carbon sugars are hexoses.

What are aldoses and ketoses?

Aldoses contain an aldehyde group at one end; ketoses contain a keto group usually at carbon 2.

What are the main characteristics of glucose?

-Glucose is a mildly sweet aldohexose with formula C6H12O6;

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-it is known as blood sugar and

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- is an essential energy source.

What are the main characteristics of fructose?

-Fructose is a ketohexose with formula C6H12O6

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- it is the sweetest carbohydrate and is found in fruits and honey

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-Added to soft drinks, cereals, deserts

What are the main characteristics of galactose?

Galactose has little sweetness and is rarely found naturally as a single sugar.

What are the chemical tests for carbohydrates?

Benedict's test detects reducing sugars such as glucose; the iodine-KI test detects starch.

What are disaccharides and the main examples?

Disaccharides contain two monosaccharides; the main examples are maltose; sucrose; and lactose.

What is maltose?

Maltose consists of two glucose units and is produced when starch is broken down by amylases.

What is sucrose?

Sucrose consists of glucose and fructose; it is the most abundant disaccharide in nature and is commonly found as table sugar.

What is lactose?

Lactose consists of glucose and galactose; it is the main carbohydrate in milk and is known as milk sugar.

What is condensation and what bond does it form?

Condensation links two monosaccharides through the release of water; the bond formed is a glycosidic bond.

What is a 1 4 glycosidic linkage?

A glycosidic bond formed between carbon 1 and carbon 4 of neighbouring monosaccharide units.

What is hydrolysis of a disaccharide?

Hydrolysis uses water to break a disaccharide into its constituent monosaccharides; it occurs during digestion.

What are complex carbohydrates?

Complex carbohydrates are polysaccharides such as starch and glycogen along with fibers such as cellulose.

What are glycogen and starch?

Glycogen is stored glucose in animals; starch is glucose stored in plant cells.

What is dietary fiber?

Plant material that escapes digestion and absorption and therefore provides minimal or no energy.

Components of fibre

-Cellulose:

complex polysaccharide made of long, unbranched chains of glucose units linked together by beta-1,4-glycosidic bonds; insoluble

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-pectins

complex polysaccharides rich in galacturonic acid ; soluble.

(especially abundant in fruits like apples and citrus fruits)

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-Lignins

complex, non-carbohydrate polymers

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-Resistant Starches

resist" digestion in the small intestine of healthy humans and pass through to the large intestine

Soluble fibers

-Viscous, fermentable, and easily digested by bacteria

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-Protection against heart disease and diabetes: By slowing down nutrient absorption, they help prevent sharp spikes in blood sugar and manage cholesterol levels

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-Lower cholesterol and glucose levels

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-Found in legumes and fruits: Common dietary sources include beans, lentils, oats, and various fruits

Insoluble Fibres

-Not easily fermented: These fibers do not dissolve in water and resist bacterial breakdown as they pass through the colon

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-Promote bowel movements and alleviate constipation

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-Found in grains and vegetables: Rich sources include whole-wheat grains, wheat bran, nuts, seeds, and fibrous vegetable skins

Explain distinction of fibers by source

Dietary fiber occurs naturally in intact plants; functional fiber is extracted from plants or manufactured

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-Dietary fibers: These are the non-digestible carbohydrates that occur naturally inside intact, whole plant foods.

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-Functional fibers: These are isolated or lab-manufactured fibers that are subsequently added to foods or supplements for health benefits

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-Total fiber: This refers to the combined sum of both natural dietary fibers and isolated functional fibers in your diet

What happens during carbohydrate digestion?

Starch undergoes extensive breakdown; disaccharides are broken down into monosaccharides; monosaccharides require no further digestion.

Digestion process

• Carbohydrate digestion begins in the mouth, where chewing mixes food with saliva containing salivary amylase, which hydrolyzes starch down into smaller polysaccharides and maltose.

  
  

• The food mixture then passes into the stomach, where no starch-digesting enzymes are present and stomach acid provides minimal breakdown, while dietary fibers contribute to a feeling of fullness.

  
  

• Digestion continues in the small intestine as pancreatic amylase reduces complex carbohydrates into smaller glucose chains and disaccharides.

  
  

• Specific brush-border enzymes then break down these remaining disaccharides into their constituent monosaccharides: maltase breaks down maltose into two glucose molecules, sucrase breaks down sucrose into glucose and fructose, and lactase breaks down lactose into glucose and galactose.

  
  

• These resulting monosaccharides are absorbed across the small intestine into the bloodstream via active transport (for glucose and galactose) and facilitated diffusion (for fructose).

  
  

• Finally, unabsorbed fiber constituents pass into the large intestine after 1 to 4 hours, where they soften stool, absorb water, and undergo partial bacterial fermentation into water, gas, and short-chain fatty acids.

Where does carbohydrate digestion occur?

Digestion begins in the mouth; little starch digestion occurs in the stomach; most digestion occurs in the small intestine; remaining fiber reaches the large intestine.

What does amylase do during carbohydrate digestion?

Salivary and pancreatic amylase hydrolyze starch into smaller polysaccharides and disaccharides such as maltose.

What do maltase sucrase and lactase do?

Maltase converts maltose to two glucose molecules; sucrase converts sucrose to glucose and fructose; lactase converts lactose to glucose and galactose.

How are carbohydrates absorbed?

Most are absorbed in the small intestine; glucose and galactose use active transport while fructose uses facilitated diffusion.

What happens to fiber in the large intestine?

Fiber attracts water and softens stool; bacteria ferment some fiber producing short-chain fatty acids and other products.

What is glucose homeostasis?

The maintenance of relatively stable blood glucose levels through hormonal regulation.

What do insulin and glucagon do?

Insulin promotes glucose uptake and storage as glycogen; glucagon stimulates glycogen breakdown and release of glucose into the blood.

What is hypoglycemia?

A condition in which blood glucose drops dramatically; causes:

- can include excessive insulin;

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-Strenuous physical activity (body burns through glucose

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I-nadequate food intake

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-illness.

What is the glycemic index?

A system for classifying foods according to their ability to raise blood glucose levels.

What are the main starches listed in the British Pharmacopoeia?

Maize; potato; rice; wheat; and cassava.

What are the pharmaceutical uses of starch?

Starch is used as an

- excipient;

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-tablet and capsule diluent;

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-disintegrant;

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-glidant

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-binder.