IJT - CIR - February 2024 - 12S

12S
International Journal of Toxicology 43(Supplement 1)
Table 7. (continued)
Constituent Groups
Aldehydes
Aliphatic alcohols
Aliphatic ketones
Carboxylic acids
Carboxylic esters
Monoterpene hydrocarbons
Oxygenated monoterpenoids
Oxygenated sesquiterpenoids
Sesquiterpene hydrocarbons
Table 8. Compounds in Humulus Lupulus (Hops) Strobile Oil.52
Classification
Compound
ND-1.3
ND-1.1
.4-8.9
ND-6.4
1.2-9.1
9.4-54.5
.4-3.5
3.3-18.4
.4-3.5
GC/MS = gas chromatography - mass spectrometry.
aHydrodistilled for 4 h with continuous extraction with dichloromethane.
bPercent composition determined from total ion current count without
correction.
Humulus lupulus (hops) oil. The cone oil of Humulus lupulus
(hops) contains secondary metabolites of the plant, which are
secreted in the lupulin glands (located on the female flower
cones/strobiles).2 The strobile oil makes up .5% to 1.5% ofthe
dried inflorescence ofHumulus lupulus (hops) strobile.49 The
strobile oil containsmany volatile constituents, including simple
oxidized alkanes, monoterpenes, and sesquiterpenes.17,50-52 It is
possible that the strobile oil contains over 1000 compounds. The
primary volatile constituents are the monoterpene β-myrcene,
and the sesquiterpenes β-caryophyllene and humulene, which
together were shown to comprise between 57% and 82% of
the volatile oil, depending on the cultivar and the method of
detection. There are only traces of2-methyl-3-buten-2-ol found
in freshly harvested strobile; after drying and storing, the
amount is higher, increasing to a maximum of approximately
.15% of the dry weight (up to 20% of the volatile constituents)
after 2 years due to degradation ofhumulones and lupulones.49
The constituents in Humulus lupulus (hops) oil are not consistent
across years or cultivars and not all ofthe constituents are
detectable in every essential oil sample; β-myrcene, linalool,
α-humulene, β-caryophyllene, undecanone-2, geranyl acetate,
humulene epoxide-2, and α-selinene are always present.53 Lists
ofsome ofthe compounds in strobile oil are provided in Table 8
and Table 9.
Humulus lupulus (hops) extract. The ethanol extract of Humulus
Lupulus (Hops) Extract is reported to contain flavonoid
and tannin.36 The butylene glycol extract ofHumulus Lupulus
(Hops) Extract is reported to contain tannin and amino acid.
Constituents of Concern
Humulus Lupulus (hops)
Humulus lupulus (hops) plants are reported to contain linalool,
quercetin, β-myrcene, 8-PN (or hopein), and other prenylated
flavonoids (Figure 1).42,43,52,54-56 Humulus lupulus (hops) oil
is reported to contain sesquiterpene lactones.17,50-52 The
Hydrocarbon, Monoterpene
α-Pinene
β-Pinene
β-Myrcene
Limonene
ρ-Cymene
Hydrocarbon, Sesquiterpene
Oxygenated, Ester
Oxygenated, Monoterpene Alcohol
Oxygenated, Monoterpene
Oxygenated, Sesquiterpene Alcohol
Oxygenated, Other
Oxygenated, Monoterpene or Ester
Oxygenated, Epoxide
Caryophyllene
E, β-Farnesene
Humulene
Methyl Heptonoate
Geraniol
Linalool
Citronellol
Farnesol
Citral
Geranyl Acetate
Humulene Epoxide 1
Humulene Epoxide 2
Table 9. Composition and Concentrations of Compounds in
Humulus lupulus (Hops) Strobile Oil Extracted by Steam Distillation
for Constituents ≥1%.108,109
Compound
α-Caryophyllene
β-Myrcene
β-Caryophyllene
γ-Cadinene
δ-Cadinene
α-Muurolene
α-Copaene
Geraniol
Sabinene
β-Selinene
Linalool
α-Selinene
(E)-β-Ocimene
Percentagea
36.7
25.4
9.8
5.5
4.1
3.0
1.5
1.5
1.4
1.2
1.1
1.0
1.0
aThis reference lists constituents at 1% or greater unless there is a safety
concern.
potential adverse effects ofexposures to these constituents are
summarized in Table 10.
The International Fragrance Association (IFRA) publishes
restrictions for fragrance ingredients. Constituents ofHumulus
lupulus (hops) that have restrictions established by IFRA are
listed in Table 11.
Humulus Lupulus (Hops) Extract. According to one supplier, the
butylene glycol extract of Humulus Lupulus (Hops) Extract
does not contain β-myrcene (detection limit .01 mg/100 g).36
A product mixture that contains approximately .18% Humulus
Lupulus (Hops) Extract (extracted with caprylic/capric

IJT - CIR - February 2024

Table of Contents for the Digital Edition of IJT - CIR - February 2024

Contents
IJT - CIR - February 2024 - Cover1
IJT - CIR - February 2024 - Cover2
IJT - CIR - February 2024 - 1S
IJT - CIR - February 2024 - 2S
IJT - CIR - February 2024 - Contents
IJT - CIR - February 2024 - 4S
IJT - CIR - February 2024 - 5S
IJT - CIR - February 2024 - 6S
IJT - CIR - February 2024 - 7S
IJT - CIR - February 2024 - 8S
IJT - CIR - February 2024 - 9S
IJT - CIR - February 2024 - 10S
IJT - CIR - February 2024 - 11S
IJT - CIR - February 2024 - 12S
IJT - CIR - February 2024 - 13S
IJT - CIR - February 2024 - 14S
IJT - CIR - February 2024 - 15S
IJT - CIR - February 2024 - 16S
IJT - CIR - February 2024 - 17S
IJT - CIR - February 2024 - 18S
IJT - CIR - February 2024 - 19S
IJT - CIR - February 2024 - 20S
IJT - CIR - February 2024 - 21S
IJT - CIR - February 2024 - 22S
IJT - CIR - February 2024 - 23S
IJT - CIR - February 2024 - 24S
IJT - CIR - February 2024 - 25S
IJT - CIR - February 2024 - 26S
IJT - CIR - February 2024 - 27S
IJT - CIR - February 2024 - 28S
IJT - CIR - February 2024 - 29S
IJT - CIR - February 2024 - 30S
IJT - CIR - February 2024 - 31S
IJT - CIR - February 2024 - 32S
IJT - CIR - February 2024 - 33S
IJT - CIR - February 2024 - 34S
IJT - CIR - February 2024 - 35S
IJT - CIR - February 2024 - 36S
IJT - CIR - February 2024 - 37S
IJT - CIR - February 2024 - 38S
IJT - CIR - February 2024 - 39S
IJT - CIR - February 2024 - 40S
IJT - CIR - February 2024 - 41S
IJT - CIR - February 2024 - 42S
IJT - CIR - February 2024 - 43S
IJT - CIR - February 2024 - 44S
IJT - CIR - February 2024 - 45S
IJT - CIR - February 2024 - 46S
IJT - CIR - February 2024 - 47S
IJT - CIR - February 2024 - 48S
IJT - CIR - February 2024 - 49S
IJT - CIR - February 2024 - 50S
IJT - CIR - February 2024 - 51S
IJT - CIR - February 2024 - 52S
IJT - CIR - February 2024 - 53S
IJT - CIR - February 2024 - 54S
IJT - CIR - February 2024 - 55S
IJT - CIR - February 2024 - 56S
IJT - CIR - February 2024 - 57S
IJT - CIR - February 2024 - 58S
IJT - CIR - February 2024 - 59S
IJT - CIR - February 2024 - 60S
IJT - CIR - February 2024 - 61S
IJT - CIR - February 2024 - 62S
IJT - CIR - February 2024 - 63S
IJT - CIR - February 2024 - 64S
IJT - CIR - February 2024 - 65S
IJT - CIR - February 2024 - 66S
IJT - CIR - February 2024 - 67S
IJT - CIR - February 2024 - 68S
IJT - CIR - February 2024 - 69S
IJT - CIR - February 2024 - 70S
IJT - CIR - February 2024 - 71S
IJT - CIR - February 2024 - 72S
IJT - CIR - February 2024 - 73S
IJT - CIR - February 2024 - 74S
IJT - CIR - February 2024 - 75S
IJT - CIR - February 2024 - 76S
IJT - CIR - February 2024 - 77S
IJT - CIR - February 2024 - 78S
IJT - CIR - February 2024 - 79S
IJT - CIR - February 2024 - 80S
IJT - CIR - February 2024 - 81S
IJT - CIR - February 2024 - 82S
IJT - CIR - February 2024 - 83S
IJT - CIR - February 2024 - 84S
IJT - CIR - February 2024 - 85S
IJT - CIR - February 2024 - 86S
IJT - CIR - February 2024 - 87S
IJT - CIR - February 2024 - 88S
IJT - CIR - February 2024 - 89S
IJT - CIR - February 2024 - 90S
IJT - CIR - February 2024 - 91S
IJT - CIR - February 2024 - 92S
IJT - CIR - February 2024 - 93S
IJT - CIR - February 2024 - 94S
IJT - CIR - February 2024 - 95S
IJT - CIR - February 2024 - 96S
IJT - CIR - February 2024 - 97S
IJT - CIR - February 2024 - 98S
IJT - CIR - February 2024 - 99S
IJT - CIR - February 2024 - 100S
IJT - CIR - February 2024 - 101S
IJT - CIR - February 2024 - 102S
IJT - CIR - February 2024 - 103S
IJT - CIR - February 2024 - 104S
IJT - CIR - February 2024 - 105S
IJT - CIR - February 2024 - 106S
IJT - CIR - February 2024 - 107S
IJT - CIR - February 2024 - 108S
IJT - CIR - February 2024 - 109S
IJT - CIR - February 2024 - 110S
IJT - CIR - February 2024 - 111S
IJT - CIR - February 2024 - 112S
IJT - CIR - February 2024 - 113S
IJT - CIR - February 2024 - 114S
IJT - CIR - February 2024 - 115S
IJT - CIR - February 2024 - 116S
IJT - CIR - February 2024 - 117S
IJT - CIR - February 2024 - 118S
IJT - CIR - February 2024 - Cover3
IJT - CIR - February 2024 - Cover4
https://www.nxtbookmedia.com