- WELCOME TO LIPIDS PART FIVE.
HERE WE'LL LOOK A LITTLE MORE CLOSELY AT EICOSANOIDS.
LET'S GET STARTED.
THERE ARE THREE MAIN CLASSES OF EICOSANOIDS.
WE'RE GOING TO FOCUS ON TWO OF THEM.
THE PROSTAGLANDINS AND THE LEUKOTRIENES.
AND WHY THESE ARE SO IMPORTANT
IS BECAUSE THEY ARE THE CHEMICAL INITIATORS OF INFLAMMATION.
AND IF YOU'VE PAID ATTENTION RECENTLY,
YOU'VE NOTICED THAT MORE AND MORE ILLNESSES ARE RELATED
TO EXCESSIVE INFLAMMATION AND THAT SORT OF THING.
SO, IT'S BECOME--
WE BECOME AWARE OF THE ROLE OF INFLAMMATION
AND ITS CONSEQUENCES TO OUR HEALTH.
SO, EICOSANOIDS ARE GROUPED TOGETHER
BECAUSE THEY'RE ALL DERIVE
FROM 20 CARBON UNSATURATED FATTY ACIDS.
SO, WHEN YOU SEE THE WORD UNSATURATED,
WHAT SHOULD COME TO MIND
IS THAT WE'RE GOING TO HAVE CARBON-CARBON DOUBLE BONDS.
AND BECAUSE WE'RE TALKING ABOUT BIOLOGICAL MOLECULES,
REMEMBER THAT IT'S--
THEY'RE ALWAYS GOING TO BE IN A CIS STEREOISOMER FORM.
ALL RIGHTY.
NOW, THE PROSTAGLANDINS AND THE LEUKOTRIENES ARE
SYNTHESIZED FROM ARACHIDONIC ACID.
SO, WHERE DO WE GET THE ARACHIDONIC ACID?
WELL, I THINK THIS IS REALLY FASCINATING.
OUR BODIES ARE SO EFFICIENT
THAT THE ARACHIDONIC ACID IS SYNTHESIZED FROM THE HYDROLYSIS
OF THE GLYCEROPHOSPHOLIPIDS IN OUR CELL MEMBRANES.
SO, THAT WAY, WE HAVE THIS CHEMICAL RESOURCE AVAILABLE
IN EVERY SINGLE CELL
BECAUSE WE RECOGNIZE THAT THE PHOSPHOLIPIDS,
RIGHT, ARE PART OF OUR--
PART OF OUR CELL MEMBRANES.
SO, WE HAVE THIS IMMUNE RESPONSE RIGHT
THERE READY WHEN WE NEED IT.
THE TRICKY PART IS,
IS THAT IT'S BEEN TRIGGERED TOO MUCH LATELY.
ALL RIGHTY.
SO, HERE IS A TYPICAL PHOSPHOLIPID.
AND, RIGHT, WE SEE THE GLYCERIN,
JUST KIND OF A QUICK REVIEW,
RIGHT, SO, THERE'S GLYCERIN.
SO, THERE'S OUR GLYCERIN BACKBONE.
AND WE SEE RIGHT THERE IS THE PHOSPHOLIPID PART.
AND SO, NOW, WE LOOK HERE AND WE SEE THE UNSATURATED CHAIN.
SO, WE CAN RECOGNIZE THAT.
IF WE COUNT THE CARBONS, WE'LL FIND THAT THERE ARE 20.
SO, NOW, WE'RE GOING TO DO A SIMPLE HYDROLYSIS REACTION.
SO, WE KNOW TO CUT THIS BOND RIGHT HERE.
AND WE'LL HAVE THE WATER COME IN.
AND HERE WE HAVE OUR HYDROLYSIS ENZYME.
AND SO, THIS NOW--
THE MOLECULES BEEN FLIPPED AROUND
BUT HERE'S THE CARBONYL CARBON.
AND THIS WOULD BE THE HYDROXYL GROUP THAT CAME FROM THE WATER.
AND SO, HERE IS OUR ARACHIDONIC ACID
WHICH WITH THOSE CIS DOUBLE BONDS GETS THAT CURVED SHAPE.
SO, SOMETIMES
WE CAN SEE ARACHIDONIC ACID WRITTEN IN A LINEAR FROM.
BUT THE--
WHERE IT'S NOT EXPLICITLY SHOWING THE CIS DOUBLE BONDS
BUT WE SEE IT'S REALLY IMPORTANT
TO RECOGNIZE THAT STRUCTURE OF THE CIS DOUBLE BONDS
BECAUSE IT HELPS US RECOGNIZE HOW IT CAN BE USED
AS A PRECURSOR SPECIALLY FOR THE PROSTAGLANDINS.
WE CAN LOOK OVER HERE AT THE--
AT THE REGION CARBONS EIGHT THROUGH TWELVE.
AND SEE THAT BECAUSE OF THE CIS DOUBLE BONDS
IT SETS US UP FOR THIS RING FORMATION.
AND THEN, HERE WE HAVE MORE GOING ON AT CARBON SIX
TO CREATE THIS PART FOR THE LEUKOTRIENES.
NOW-- SO, NOW, I JUST WANT TO CONNECT
THIS WITH WHAT WE'RE LEARNING ABOUT OUR MOLECULAR PORTFOLIOS
ABOUT DRUGS.
SO, THE PROSTAGLANDINS, RIGHT,
SO, THE PROSTAGLANDIN WILL ACTUALLY TRIGGER INFLAMMATION.
SO, IF WE'RE TRYING TO AVOID INFLAMMATION,
WE CAN USE DRUGS CALLED NON-STEROIDAL
ANTI-INFLAMMATORY DRUGS.
SO, WE JUST TALKED ABOUT CHOLESTEROL
IN THE PREVIOUS VIDEO,
WE CAN-- SO, WE CAN SEE THIS IS--
THESE ARE DEFINITELY NOT STEROIDS.
THERE'S NO FUSED RINGS.
SO, LETS MAKE SURE EVERYBODY HAS THIS ACRONYM DOWN, RIGHT,
SO, NON-STEROIDAL ANTI-INFLAMMATORY DRUGS.
AND SO, THESE ARE EXAMPLES OF LIKE ASPIRIN IS AN EXAMPLE.
AND THE WAY THEY WORK IS THAT WE SEE HERE THAT THERE IS SEVERAL
ENZYME-CATALYZED STEPS THAT MUST OCCUR.
WELL, ONE OF THOSE ENZYMES IS
CYCLOOXYGENASE.
AND SO, WHAT HAPPENS IS THESE NON-STEROIDAL
ANTI-INFLAMMATORY DRUGS, THEY INHIBIT THIS ENZYME
AND PREVENT THE FORMATION OF THE PROSTAGLANDINS.
AND SO, BACK IN OUR PROTEIN AND ENZYME CHAPTER,
WE LOOKED AT INHIBITION.
SO, HERE IS AN EXAMPLE WHERE WE HAVE THE INHIBITION OF AN ENZYME
TO PREVENT THE COMPOUND THAT TRIGGERS INFLAMMATION.
FOR THE LEUKOTRIENE PATHWAY, THE ENZYME--
ONE OF THE MAJOR ENZYMES HERE IS 5-LIPOXYGENASE,
RIGHT, USING THE SUFFIXES TO RECOGNIZE THAT THEY'RE ENZYMES.
AND SO, THEN, THERE'S ANOTHER CLASS OF DRUGS
THAT ARE CALLED LIPOXY, MAKES SENSE.
LIPOXYGENASE, RIGHT, INHIBITORS.
SO, YOU SEE THAT BOTH FORMS OF DRUGS,
TO PREVENT INFLAMMATION WORK BY INHIBITING THE ENZYMES
THAT WOULD PRODUCE THE BIOLOGICAL MOLECULE
THAT TRIGGERS INFLAMMATION.
SO, THERE'S NOT--
YOU KNOW, THAT PRETTY MUCH WRAPS IT UP.
THAT'S ALL YOU'RE RESPONSIBLE FOR WITH EICOSANOIDS.
SO, YOU WANT TO KNOW ABOUT THE--
WHERE THE ARACHIDONIC ACID COMES FROM,
THE HYDROLYSIS OF THE PHOSPHOLIPID,
AND THEN, THE ROLE OF THE ANTI-INFLAMMATORY DRUGS
TO INHIBIT THE ENZYMES.
SO, TAKE TIME NOW TO WORK A FEW HOMEWORK PROBLEMS
TO REINFORCE YOUR UNDERSTANDING.