Olfaction & Perception

Transcription

1 lfaction & Perception

2 "Press Release: The 2004 Nobel Prize in Physiology or Medicine". Nobelprize.org. 19 ct nobel_prizes/medicine/laureates/2004/press.html

3 dor molecules are generally: Detectable - Volatile! < 300 g/mol Hydrophobic/Hydrophilic

4 The Cell Surface N P phosphatidylcholine H NH 2 Hydrophillic end H sphingosine Hydrophobic end H HN H ceramide N P HN H sphingomyelin H H H H cholesterol

5 Phospholipid Bilayer H 2 H 2 Cellular contents are isolated from extracellular environment

6 lfactory Receptors and the 7-Transmembrane G-protein coupled receptor proteins (GCPR) Extracellular Hydrophillic Region Hydrophobic Region Lipid bilayer Receptor protein Intracellular Hydrophillic Region Cholesterol

7 G-protein-coupled receptors (7-TM receptors) Structure - Single protein with 7 transmembrane regions Extracellular loops NH 2 N -Terminal chain Membrane VII VI V IV III II I Transmembrane helix G-Protein binding region H 2 C C -Terminal chain Intracellular loops

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9 ot ~ ppb ot ~ ppb ot ~ 61 ppb ot ~ 223 ppb Molecular Weight: ot ~ 0.44 ppb ot ~ 0.13 ppb Molecular Weight:

10 caraway spearmint (S)-Carvone (R)-Carvone

11 lfactory Receptors and the 7-Transmembrane G-protein coupled receptor proteins (GCPR)

12 The camp Transduction Cascade Interaction of receptor with G-protein Ligand Receptor Cell membrane γ ß α G Protein Ligand binding Induced fit γ α ß G-protein binds Induced fit for G-protein γ ß α GDP GTP Binding site for G-protein opens = GDP Guanosine diphosphate Guanosine triphosphate

13 γ ß γ ß α GTP binds α Fragmentation and release Induced fit Binding site recognizes GTP G-protein alters α-subunit shape Complex destabilized γ ß α

14 Interaction of α-subunit with adenylate cyclase Binding site for α-subunit GTP GDP α-subunit Adenylate cyclase Binding camp acts as hormone that activates Ca 2+ ion channels Induced fit ATP cyclic AMP Signal transduction via axons Active site (closed) Active site (open)

15 Sound Like ALT to Remember? Summary γ α ß 1. dorant (ligand) binds receptor, which then binds G-protein 2. GDP leaves and GTP binds, resulting in destabilizing complex 3. α-subunit binds adenylate cyclase where ATP is converted to camp 4. camp activates Ca2+ ion channels resulting in signal transduction GDP GTP ATP cyclic AMP

16 Receptor cells lfactory bulb Hypothalamus emotion and memory lfactory cortex

17 Fragrance Perception Humans use different types of olfactory receptors - variations among individuals Statistically, each individual may detect odor with different combination of receptors dor - Emotion, each individual response may depend on previous experiences Market Research - understanding your customers Sensory Analysis - using humans as measuring tool Can you discriminate between odors? Can you recognize odors (vocabulary)?

18 Sensory Analysis dor Threshold Floral-musk, 200 ppb (in water) Classical musky odor, 0.7 ng/l (in air) Powerful musk odor, ppb (in air) 1 ppb (part per billion) = 1 microgram/l = g/l = % 1,000,000 microgram = 1 gram 1 ng = g

19 Sensory Analysis dor Threshold H H (-) ambrox mp = 75 C vp ~ 0.01 mm 25 C ot ~ 1 ppb maltol mp = 162 C vp = mm 25 C ot ~ 35,000 ppb

20 Sensory Analysis dor Profiling Animal: Refers to the warm, sensual and heady base notes once associated with the natural odor of musk, ambergris, civet, and castoreum, now produced by some vegetable materials and aroma chemicals. Amber: Rich, spicy, warm, sweet and sensual. Smooth, rich and intoxicating, amber is one of the hardest fragrances to describe. Balsamic: Pungent, fresh. A heavy scent that calls to mind sticky sap. (balsamic vinegar, mint, pine) Green: Penetrating and spontaneous, this derives above all from leaves, stalks or freshly cut grass. Lively and bubbly, it can be traced back to certain flowers such as Violet, or fruits, such as Watermelon. Herbaceous: Aromatic and sharp, deriving from the plant kingdom, these are closely linked to the green notes, whilst at the same time taking on more complex characteristics. They are particularly aromatic and in general have a scent similar to that of the earth, therefore grass and roots.

21 Sensory Analysis dor Profiling Marine/zone: Lively and effervescent, fresh and agreeable, these notes remind us of water, the sea and the ozone. Musky: Intense and persistent, typically masculine. In most cases, the smell reminds us of wood, resin and earth. Spicy: Lively or pungent notes such as clove oil, cinnamon; characteristic of notes of carnation, ginger, lavender or the chemical spicy notes of eugenol or isoeugenol. Woody: An odor which is linked to the aroma of freshly cut, dry wood or fibrous root such as sandalwood or vetiver.

22 Sensory Analysis dor Profiling Pane llist: Date : Sample ID Flor al Fru ity Citr us Herba l Gr ee n Mint Mar ine Sweet Spicy Woo dy Fr es h

23 Sensory Analysis dor Profiling Floral Fruity Citrus Herbal Mint Sweet Woody Fresh

24 Sensory Analysis dor Profiling H raspberry ketone hedione C 2 Me Pharaone A B C

25 Sensory Analysis dor Profiling Top note (15-25%) Middle note (30-40%) Base/bottom note (45-55%)

26 Sensory Analysis dor Profiling - Multidimensional scaling map

27 Sensory Analysis dor Profiling