Lycopene bent rather than linear shape. Different isomers were shown to have different stabilities due to their molecular energy (highest stability: 5-cis ≥ all-trans ≥ 9-cis ≥ 13-cis > 15-cis > 7-cis > 11-cis: lowest). In human blood, various "cis"-isomers constitute more than 60% of the total lycopene concentration, but the biological effects of individual isomers have not been investigated. Carotenoids like lycopene are found in photosynthetic pigment-protein complexes in plants, photosynthetic bacteria, fungi, and algae. They are responsible for the bright orange–red colors of fruits and vegetables, perform various functions in photosynthesis, and protect photosynthetic organisms from excessive light damage.
Lycopene contain lycopene, e.g., asparagus, which contains about 30 μg of lycopene per 100-g serving (0.3 μg/g) and dried parsley and basil, which contain around 3.5-7.0 μg/g of lycopene. In humans, the Observed Safe Level for lycopene is 75 mg/day, according to one preliminary study. Lycopene is non-toxic and commonly found in the diet, mainly from tomato products. There are cases of intolerance or allergic reaction to dietary lycopene, which may cause diarrhea, nausea, stomach pain or cramps, gas, and loss of appetite. Lycopene may increase the risk of bleeding when taken with anticoagulant drugs. Because lycopene may cause low blood