Kaempferol
IUPAC name 3,5,7-Trihydroxy-2-(4-hydroxyphenyl)-4H-chromen-4-one
Other names Kaempherol; Robigenin; Pelargidenolon; Rhamnolutein; Rhamnolutin; Populnetin; Trifolitin; Kempferol; Swartziol; 3,5,7-trihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one
Identifiers
CAS number	520-18-3 Y
PubChem	5280863
KEGG	C05903 N
ChEMBL	CHEMBL150 N
Jmol-3D images	Image 1
SMILES C1=CC(=CC=C1C2=C(C(=O)C3=C(C=C(C=C3O2)O)O)O)O
Properties
Molecular formula	C15H10O6
Molar mass	286.23 g/mol
Melting point	276–278 °C
N (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Kaempferol is a natural flavonol, a type of flavonoid.

Chemistry[link]

Kaempferol is a yellow crystalline solid with a melting point of 276–278 °C. It is slightly soluble in water but soluble in hot ethanol and diethyl ether.

Natural occurrences[link]

It can be isolated from tea,^[1] broccoli, Delphinium, Witch-hazel, grapefruit, cabbage, kale, beans, endive, leek, tomato, strawberries, grapes, brussels sprouts, apples and other plant sources.

Kaempferol and its glucoside can be isolated from the methanolic extract of fronds of the fern Phegopteris connectilis. ^[2]

Biological activity[link]

Some epidemiological studies have found a positive association between the consumption of foods containing kaempferol and a reduced risk of developing several disorders such as cancer and cardiovascular diseases. Numerous preclinical studies have shown that kaempferol and some glycosides of kaempferol have a wide range of pharmacological activities, including antioxidant, anti-inflammatory, antimicrobial, anticancer, cardioprotective, neuroprotective, antidiabetic, anti-osteoporotic, estrogenic/antiestrogenic, anxiolytic, analgesic and antiallergic activities (see review article).^[3]

Many glycosides of kaempferol, such as kaempferitrin and astragalin, have been isolated as natural products from plants. Kaempferol consumption in tea and broccoli has been associated with reduced risk of heart disease.^[4] A related compound, Naringenin may be present at the same time, such as in grapefruit.

Kaempferol is what gives the flowers of Acacia decurrens and Acacia longifolia their color.^[5] Antidepressant properties have been reported in tests on animals.^{[6][unreliable source?][7]},^[8]

An 8-year study found that three flavonols (kaempferol, quercetin, and myricetin) reduced the risk of pancreatic cancer by 23 percent.^[9]

Kaempferol consumption appears to reduce lung cancer incidence.^[10]

Kaempferol may be a potent prophylactic against NOX-mediated neurodegeneration.^[11]

Metabolism[link]

The enzyme kaempferol 4'-O-methyltransferase uses S-adenosyl methionine and kaempferol to produce S-adenosylhomocysteine and kaempferide.

Glycosides[link]

• Astragalin (Astragaline, asragalin, kaempferol-3-O-glucoside)
• Kaempferitrin
• Kaempferol-3-O-β-D-glucopyranoside-7-O-α-L-rhamnopyranoside, a known bitter-tasting flavonoid glycoside, can be isolated from the rhizomes of Selliguea feei.^[12]
• Kaempferol 7-O-glucoside
• Robinin
• Sophoraflavonoloside (kaempferol 3-O-sophoroside)
• Trifolin

List of the plants that contains the chemical[link]

Kaempferol has been identified in many edible plants. It has been found in Allium ampeloprasum (leek), Allium cepa (onion), Allium schoenoprasum (chives), Amaranthus lividus (amaranth), Angelica keiskei (ashitaba), Armoracia rusticana (horseradish), Artemisia dracunculus (tarragon), Atriplex hortensis (orach), Brassica campestris (Chinese cabbage), Brassica juncea (mustard), Brassica napobrassica (rutabagas), Brassica oleracea (broccoli, brussels sprouts, green cabbage and kale), Brassica rapa (turnip greens), Bunias orientalis (Turkish rocket), Camellia sinensis (tea), Capparis spinosa (capers), Celosia argentea (feather cockscomb), Cichorium endivia (endive), Citrus paradisi (grapefruit), Cnidoscolus aconitifolius and C. chayamansa(tree spinach), Coccinia grandis (ivy gourd), Cucumis sativus (cucumber), Cucurbita maxima (squash), Cyamopsis tetragonoloba (cluster bean), Diplotaxis erucoides (wall rocket), Diplotaxis tenuifolia (wild rocket), Eruca sativa (rocket-salad), Foeniculum vulgare (fennel), Fragaria vesca (strawberry), Houttuynia cordata (fishwort), Ipomoea batatas (sweet potato), Lactuca sativa (lettuce), Lepidium sativum (cress), Levisticum officinale (lovage), Lycium barbarum and L. chinense (goji berries), Malus domestica (apple), Momordica cochinchinensis (gac), Morinda citrifolia (Indian mulberry), Nasturtium officinale (watercress), Nepenthes gracilis ^[13], Olea europaea (olive oil), Petroselinum crispum (parsley), Phaseolus vulgaris (green beans), Pistacia vera (pistachio), Prunus persica (peach), Raphanus sativus (radishes), Ribes uva-crispa (gooseberries), Rubís fruticosus (blackberries), Rubus idaeus (raspberry), Sambucus nigra (elderberry), Sauropus androgynus (star gooseberry), Sesbania grandiflora (sesbania), Solanum lycopersicum (tomatoes), Solanum nigrum (nightshade), Solanum tuberosum (potatoes), Spinacia oleracea (spinach), Vaccinium erythrocarpum, V. acrocarpon, V. microcarpum and V. oxycoccos (cranberries), Vaccinium vitis-idaea (cowberries), Vicia faba (broadbeans) Vigna unguiculata (cowpea), Vitis rotundifolia (muscadine grapes) and Vitis vinífera (grapes).^[3]

Kaempferol has been identified in many plant species commonly used in traditional medicine. It has been found in Acacia nilotica, Adansonia digitata, Albizia lebbeck, Aloe vera, Amburana cearensis, Ammi majus, Angelica keiskei, Ardisia japonica, Bauhinia forficata, Bauhinia microstachya, Bunium persicum, Capparis spinosa, Cassia alata, Centella asiatica, Chromolaena odorata, Cissus sicyoides, Coccinia grandis, Crassocephalum crepidioides, Crocus sativus, Cynanchum acutum, Cynanchum chinense, Dicliptera chinensis, Equisetum arvense, Euphorbia pekinensis, Ficaria verna, Foeniculum vulgare, Galega officinalis, Ginkgo biloba, Glycine max, Grindelia robusta, Gymnema sylvestre, Helleborus niger, Hippophae rhamnoides, Houttuynia cordata, Hypericum perforatum, Impatiens balsamina, Lamium album, Laurus nobilis, Lonicera japonica, Lycium barbarum, Lycium chinense, Lysimachia vulgaris, Malva parviflora, Peumus boldus, Phyllanthus emblica, Ribes nigrum, Rosmarinus officinalis, Sambucus nigra, Sanguisorba minor, Siraitia grosvenori, Solanum nigrum, Solenostemma argel, Solidago virgaaurea, Sutherlandia frutescens, Symphytum officinale, Syzygium aromaticum, Tilia americana, Toona sinensis, Trigonella foenum-graecum, Tropaeolum majus, Vaccinium vitis-idaea, Warburgia ugandensis and Wedelia trilobata.^[3]

Kaempferol is also present in Kaempferia galanga^[14] and Opuntia ficus-indica var. saboten.^[15]

Kaempferol as a longevity promoting agent[link]

The SIRT1 member of sirtuin deacetylases has been shown, along with PGC-1α, to mediate the life span extension associated with caloric restriction. SIRT1 deacetylates protein substrates, thus altering their activity or function. SIRT1 interacts directly with PGC-1α to mediate gluconeogenesis and mitochondrial biogenesis by deacetylating and activating PGC-1α. The activators of SIRT1 polyphenols resveratrol and kaempferol have been shown to increase mitochondrial function and energy expenditure.^[16]

A study used the multicellular model organism nematode Caenorhabditis elegans to examine the effects of the flavonoids kaempferol and fisetin on their protective action in individual living worms. The results showed that both flavonoids increased the survival of C. elegans, reduced the intracellular reactive oxygen species(ROS) accumulation at lethal thermal stress, and diminished the extent of induced oxidative stress. Kaempferol had a stronger impact. Kaempferol also attenuated the accumulation of the ageing marker lipofuscin suggesting a life prolonging activity of this flavonoid. Fisetin did not have this effect.^[17]

References[link]

External links[link]

• Flavonoid composition of tea: Comparison of black and green teas