2-undecanone, also known as methyl nonyl ketone, is a colorless to slightly yellow liquid and has a characteristic rue odor with a sweet flavor reminiscent of peach (on dilution). It naturally exists in Houttuynia cordata, bananas, strawberries, cloves, ginger and Rutaceae plants. The FEMA number is 3093, the FDA number is 172.515, and the CoE number is 150. methyl nonyl ketone is the active ingredient of Houttuynia cordata, mainly used in the production of medicines and fragrances, and is safer and more effective than DEET for mosquito repellents.
Originally reported found in the essential oils of Ruta graveolens; subsequently was identified in the essential
oils of Citrus limetta Risso., Fagara xanthoxyloides Lamm. and Litsea odorifera Val. (leaves); a method for the determination of
methyl nonyl ketone in various rue species (Ruta montana, Ruta bracteosa) was devised; it is also present in the essential oils of
Jaborandi (leaves), Hottuynia cordata, Phellodendron anaurense, Schizandar nigra Maxim., and in coconut and palm oils; also
identified as the main constituent of the essential oil of Boronia ledifolia Gai; a 92% content level was reported in the essential
oil of Ruta chalepensis. Also reported found in rabbiteye, blueberry, feijoa fruit, feijoa peel, peach, raspberry, fresh black berry,
heated blackberry, strawberry jam, guava, allium, cloves, raw asparagus, shallot, roasted onion, ginger, Curcuma aeruginosa Roxb.,
Curcuma heyneana Val., banana, grapefruit, currants, peach, asparagus, shallot, onion, leek, chive, peas, potato, clove, ginger, pepper,
many cheeses, wheaten bread, butter, milk, cream, yogurt, milk powder, goat and sheep milk, caviar, raw and smoked fatty fish,
roast chicken, cooked beef, beef, chicken and pork fat, hop oil, beer, cognac, rum, sparkling wine, coffee, tea, roasted filberts and
peanuts, coconut meat, milk and oil, passion fruit, mushroom, wild marjoram, starfruit, Brazil nut, cardamom, rice, buckwheat, corn
oil, wort, elder flower, shrimp, crayfish, clam, maté and mastic gum leaf and fruit oil.