Lec 6: Lutein & Garlic Exam 2

Lutein

naturally occurring yellow/orange carotenoid obtained in the diet, commonly found in fruits and vegetables, dark-green vegetables, kale, spinach, turnip greens, and collards

Lutein is only synthesized in

plants, and animals obtain lutein through eating plants

For plants to resist oxidation they...

produce bioactive compounds like lutein

Lutein is an isomer of ...

zeaxanthin, is present un plants as fatty acid esters (lipophilic)

Lutein absorbs

light due to the presence of conjugated double bonds, it absorbs blue light and appears yellow at low concentrations and orange/red at high concentrations

Lutein also exists in

photoautotrophic organisms like algae-spirulina, chlorella

Lutein production in microalgae is .... compared to plants

significantly, 3-6X, higher

Lutein structure

extended conjugated double-bond system, polyene chain exists in cis or trans form. Light, oxygen, heat, pH can convert trans carotenoids into cis carotenoids. This is not ideal because trans-lutein has higher bioavailability

Lutein hydroxyl group position

at both ends of lutein and they react with fatty acids to form mono-esters or di-esters

Lutein is an ester within plants and

can be converted to free lutein via saponification with alkali, addition of a base converts ester into free form

Lutein esters are

more stable when subjected to heat/light and maintain stable color profile compared to free lutein

Bioavailability of lutein ester is..... and the biological effects

higher compared to the free form and the biological effects are different for ester and free form

Biological activities of lutein

selective distribution within tissues, macular retina, adrenal gland, liver

prevents age-related macular degeneration, improves skin hydration and elasticity

reduces blood pressure and cholesterol, stimulates immune function and cancer prevention

Lutein safety

not known to be toxic at higher amounts of ingestion >30mg, even consumption at 400mg/kg bw/day does not cause adverse effects

Garlic (Allium sativum) possesses

valuable medicinal properties and is rich is phytochemicals

about 85% of garlic production in the US is in

california

Garlic supplement examples

essential oil, garlic oil macerate, garlic powder, and garlic extract

garlic contains

sulfur containing compounds such as allicin

Precursors to sulfur compounds

gamma-glutamyl-S-alkenyl-L-cysteine (more stable, umami flavor, concentration increases during storage because S-alkenyl degrades) and S-alkenyl-L-cysteine sulfoxides (alliin)

Garlic also contains

micronutrients (calcium, magnesium, phosphorus, potassium, selenium, vitamin C, and folate)

Garlic odor arises from ... when the bulb is damaged

allicin and oil-soluble sulfur compounds, membrane destruction results in organosulfur degradation due to enzymatic action

Alliinase converts

alliin to form odiferous thiosulfinates (allicin)

Bioavailability of allicin

between 65-95%

Cooking degrades

alliinase enzyme so there is no strong smell form allicin (allicin not produce if enzyme is denatured), heat/drying of garlic for capsule supplement with no odor/flavor

In oil form allicin reaches the blood flow in ...

10 minutes

Allicin degrades into

sulfides, ajoene, and dithiins

strong garlic flavor is associated with

higher amounts of volatile sulfur compounds

Biological activities of garlic

antihypertensive, anti-Alzheimer's, anticancer, anti-inflammatory, antimicrobial, antidiabetic

Difference in lutein and zeaxanthin structure

Both consist of long chains of conjugated double bonds with ionone rings on the ends. Zeaxanthin has two beta-ionone rings and lutein has one beta ionone ring and one epsilon ionone ring