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Phospholipids and steroids

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Contents:

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 Introduction to Phospholipids and steroids
 Phospholipids
 Definition
 Structure
 Composition
 Functions
 Amphipathic character
 Applications
 Simulations
 Characterization
 Analysis
 Phospholipids synthesis
 Sources
 Phospholipid role in biotechnology
 Examples
 Steroids
 Definition
 Types
o Intact ring system
o Cleaved, contracted, and expanded rings
 Function
 Structure
 Examples
 Role in biotechnology
 Difference between phospholipids and steroids
 References

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INTRODUCTION:
Phospholipids are a class of lipids that are a major component of all cell membranes
...
The structure of the phospholipid
molecule generally consists of two hydrophobic fatty acid "tails" and
a hydrophilic phosphate "head", joined together by a glycerol molecule
...
A steroid is an organic
compound with four rings arranged in a specific configuration
...
Steroids have two principal biological functions: certain
steroids (such as cholesterol) are important components of cell membranes which
alter membrane fluidity, and many steroids are signaling molecules which activate steroid
hormone receptors
...
g
...

Structure of Phospholipids:
Your body is a complicated machine, so you may be surprised to learn that important biological
molecules that make up living things fall into only four main classes: carbohydrates, lipids,
proteins, and nucleic acids
...
Phospholipids
consist of a hydrophilic (or 'water loving') head and a hydrophobic (or 'water fearing') tail
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This layer makes up your cell membranes and is critical to a cell's
ability to function
...


Composition of Phospholipids:
Lipids all have one thing in common - they do not mix well with water
...
No matter how much or how hard you shake them
together, they remain separated
...
For example, ducks produce
lipids in their feathers, allowing the water to roll right off their backs and helping the ducks stay
afloat
...
' The glycerol molecule is also attached to a phosphate
group, and this is the hydrophilic part of the molecule
...
[2]

Functions of phospholipids:
Phospholipids serve a major function in the cells of all organisms: they form the phospholipid
membranes that surround the cell and intracellular organelles such as the mitochondria
...
The membrane is fluid at physiological temperatures and allows cells to change
shape due to physical constraints or changing cellular volumes
...

This semi-permeable nature of the membrane allows the cell to maintain the composition of the
cytoplasm independent of the external environment
...
The fatty acid
chains act as the tails of the phospholipid while glycerol acts as a head
...
The phosphate group causes the glycerol head to become
hydrophilic
...
[4]

Fig 3: Cell membrane consist of phospholipid bilayers

APPLICATIONS:
Phospholipids have been widely used to prepare liposomal, ethosomal and other
nanoformulations of topical, oral and parenteral drugs for differing reasons like improved bioavailability, reduced toxicity and increased penetration
...
Liposomes are often composed of phosphatidylcholine-enriched phospholipids and
may also contain mixed Phospholipid chains with surfactant properties
...


Characterization:
Phospholipids are optically highly birefringent, i
...
their refractive index is different along their
axis as opposed to perpendicular to it
...
g
...


Analysis:
There are no simple methods available for analysis of Phospholipids since the close range of
polarity between different phospholipid species makes detection difficult
...
Lipidomists use more absolute
methods of analysis of with nuclear magnetic resonance spectroscopy (NMR), particularly 31PNMR while HPLC-ELSD provides relative values
...
Eventually a vesicle will bud off
from the ER containing phospholipids destined for the cytoplasmic cellular membrane on its
exterior leaflet and phospholipids destined for the exoplasmic cellular membrane on its inner
leaflet
...
Each source has a unique profile of individual phospholipid
species and consequently differing applications in food, nutrition, pharmaceuticals, cosmetics
and drug delivery
...
All sites of phospholipids can be selectively modified by
enzymatic catalysis
...
Phospholipids find
application as pharmaceuticals, food additives, cosmetics, in liposome technology and in gene
transfer therapy
...
Two major categories of phospholipids
are glycerophospholipids and phosphosphingolipids
...
[6]

Examples:

Phosphatidylglycerol

Phosphatidylcholine

STEROIDS:
Definition:
Any of a large class of organic compounds with a characteristic molecular structure containing
four rings of carbon atoms (three six-membered and one five)
...


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Types of steroids :
Intact ring system:
It is also possible to classify steroids based upon their chemical composition
...
Examples
from this classification include:
Class
Cholestanes
Cholanes
Pregnanes
Androstanes
Estranes

Examples
cholesterol
cholic acid
progesterone
testosterone
estradiol

Number of carbon atoms
27
24
21
19
18

The gonane (or steroid nucleus) is the parent (17-carbon tetracyclic) hydrocarbon molecule
without any alkyl sidechains
...
seco, "to cut") are a subclass of steroidal compounds resulting, biosynthetically
or conceptually, via scission (cleavage) of parent steroid rings, generally one of the four
...
For instance, the prototypical secosteroid cholecalciferol, vitamin D3 (shown), is in the
important 9,10-secosteroid subclass, derived via cleavage between carbon atoms C-9 and C-10 of
the steroid B-ring (similarly 5,6-secosteroids, 13,14-steroids, etc
...
norma, from "normal" in chemistry, indicating carbon removal)
andhomosteroids (homo-, Gk
...
These two classes represent further unique
classes of steroids with important biological activities and societal impacts; the effect of these
chemical operations on the ring structures is such that recognition of the parent tetracyclic ring
system can be challenging
...
For example, steroid hormones
are secreted by the testes and ovaries
...
From the ovaries, we see estrogen, which is the
female sex hormone that guides female sexual development
...
Cortisol is one important adrenal
cortex steroid hormone, and it regulates carbohydrate metabolism and has an anti-inflammatory
effect on the body
...
It
helps maintain blood pressure and regulate the salt and water balance in your body
...
We see that steroids are organic compounds
that contain four rings of carbon atoms
...

However, different steroids have different functional groups attached
...
When we
attach different functional groups to the basic steroid rings, we get steroids with different
functions
...

But first, we mentioned that steroids are organic compounds, and we know that organic
compounds must contain carbon
...
In fact, steroids are classified under the lipid group
...
However, steroids still fit this category
because, like other fats, steroids are made largely of carbon and hydrogen atoms, and they are
insoluble in water
...
Steroids are widely used
as therapeutic agents and since their inception in the market, research efforts have been made in
order to improve production processes as well as to develop novel synthetic molecules, with
enhanced efficiency and reduced side effects
...
Still, steroid molecules present multiple chiral centers, a feature that makes
particularly appealing the use of the selective microbial catalysts to provide a pathway that does
not require protection, and additional deprotection steps
...
[9]

Difference between phospholipids and steroids:
The name of phospholipid is somewhat self-explanatory
...
The phosphate group is on the head of the
phospholipid
...
The other end is
made of long chains of hydrocarbons making it hydrophobic or repelling water
...

Steroids contain a cholesterol backbone which is rigid
...
Structurally,
steroids have large aromatic rings, much like benezene making up most of its structure
...
Also, steroids mostly function as hormones such as testosterone or estrogen
...
https://en
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org/wiki/Phospholipid
2
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com/academy/lesson/what-is-a-phospholipid-structure-functionscomposition
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http://telstar
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cmu
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html
4
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reference
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https://en
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org/wiki/Phospholipid
6
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cell
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https://en
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org/wiki/Steroid
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com/academy/lesson/steroids-structure-function
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http://onlinelibrary
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com/doi/10
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eib556/abstract
10
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yahoo

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