Table 2: Phytochemical concentrations in floral tissues, pollen, nectar, and honey.

From: Bumble bee parasite strains vary in resistance to phytochemicals

CompoundSample typePlant speciesConcentration (ppm)*Reference
Pyridine alkaloids
 flowersN. noctiflora235140
 flowersN. petunioides148240
 nectarN. glauca563
 nectar32 Nicotiana spp0–1.5240
 nectarN. tabacum0–1.098
 nectar32 Nicotiana spp.0–5.3840
 nectarN. attenuata441
 nectarN. glauca0.563
Cyanogenic glycosides
 pollenAmygdalus communis188999
 nectarAmygdalus communis4–1099
Hydroxycinnamic acids
Caffeic acid
 honeyQuercus robur26.853
 honeyTilia platyphyllos8.853
 honeyFagopyrum esculentum7.07100
 honeyPhlomis armeniaca6.653
 honeyEryngium campestre6.1853
 honeyAstragalus microcephalus5.1453
 honeyCastanea sativa4.8353
Chlorogenic acids
5-O-caffeoylquinic acidpollenPersea americana1525 ± 486 SD (n = 30)This study
5-O-caffeoylquinic acidpollenMalus domestica475 ± 862 SD (n = 30)This study
5-O-caffeoylquinic acidpollenVaccinium corymbosum (cult.)430 ± 404 SD (n = 53)This study
5-O-caffeoylquinic acidpollenVaccinium corymbosum (wild)192 ± 204 SD (n = 30)This study
3-O-caffeoylquinic acidnectarPrunus dulcis25.0 ± 14.9 SD (n = 15)This study
5-O-caffeoylquinic acidnectarMalus domestica15.6 ± 15.2 SD (n = 30)This study
5-O-caffeoylquinic acidnectarVaccinium corymbosum (cult.)14.6 ± 28.2 SD (n = 52)This study
5-O-caffeoylquinic acidnectarVaccinium corymbosum (wild)7.52 ± 4.23 SD (n = 29)This study
4-O-caffeoylquinic acidnectarVaccinium corymbosum (wild)6.66 ± 5.11 SD (n = 30)This study
4-O-caffeoylquinic acidnectarVaccinium corymbosum (cult.)3.77 ± 7.62 SD (n = 55)This study
3-O-caffeoylquinic acidhoneyLeptospermum scoparium8.2101
3-O-caffeoylquinic acidhoneyTilia spp0.21100
3-O-caffeoylquinic acidhoneyBrassica rapa0.17100
 bud essential oilSyzygium aromaticum86.70%96
 floral essential oilOcimum selloi66.20%102
(methyl eugenol)floral essential oilRosa rugosa6.88%103
 floral volatilesRhizophora stylosa27.20%104
 pollen volatilesRosa rugosa>2%73
(eugenol + methyl eugenol)stamensRosa x hybrida49.9105
 petals (male)Cucurbita pepo cv. Tosca1.2106
 petals (female)Cucurbita pepo cv. Tosca0.99106
 antherCucurbita pepo cv. Tosca0.57106
 Nectar (male and female)Cucurbita pepo cv. Toscatrace106
 stigmaCucurbita pepo cv. ToscaND106
 honeyRosmarinus spp0.02–0.03107
 honeyThymus spp0.016108
Trihydroxybenzoic acids
Gallic acid
 honeyQuercus robur82.553
 honeyLeptospermum scoparium70.5101
 honeyLeptospermum polygalifolium12.3101
 honeyFagopyrum esculentum9.1100
 honeyTilia spp3.26100
 honeyBrassica rapa1.27100
 honeyCastanea sativus0.9153
 honeyCalluna vulgaris0.6153
 floral volatilesArabidopsis thaliana40%109
 floral volatilesNicotiana sylvestris35%110
 floral volatilesDianthus caryophyllus23%111
 floral volatilesCitrus limon9.50%112
 pollen volatilesCitrus limon14.50%112
 pollen volatilesPapaver rhoaeus>5%113
 pollen volatilesLupinus polyphyllus>5%113
 pollen volatilesLaurus nobilis3.40%114
 stamen volatilesLaurus nobilis15.40%114
 flower bud volatilesCitrus limon11.90%112
 petal volatilesCitrus limon2.50%112
 nectarThymus vulgaris cv. Silver8.2 (n = 1)This study
 nectarThymus vulgaris cv. German5.2 ± 2.98 SD (n = 11)This study
 honeyApigard™-treated hives0.5–2.65115
 honeyCalluna vulgaris0.346116
 honeyThymus spp.0.27115
 honeyTilia spp0.16117
 honeyErica spp.)0.142116
 honeyErica spp.0.12115
  1. Concentration measurements for chlorogenic acid and thymol (bold) are from this study’s field sampling of nectar and pollen. Sample sizes are in parentheses. Concentrations of other phytochemicals were compiled through literature searches. Data are arranged in order of decreasing maximum concentration, first for sample types within compounds, and then by observations within a given sample type. SD: Standard Deviation. *Units are mean concentration by mass in ppm, except for values followed by a “%” sign, which indicates % of total volatiles (for compounds where ppm concentrations were unavailable).