Α-Farnesene

• CAS: 502-61-4
• Catalog Number: ACM502614-2
• Category: Main Products
• Molecular Weight: 204.35
• Molecular Formula: C15H24
• Synonyms: (E,E)-3,7,11-Trimethyl-1,3,6,10-dodecatetraene; Farnesene; (3E,6E)-α-Farnesene; (E,E)-α-Farnesene; alpha-Farnesene; trans,trans-α-Farnesene; trans-2,6,10-Trimethyl-2,6,9,11-dodecatetraene; trans-3,7,11-Trimethyl-1,3,6,10-dodecatetraene; trans-α-Farnesene
• Melting Point: N/A
• Solubility: Chloroform (Slightly), Ethyl Acetate (Slightly), Methanol (Slightly)
• Appearance: Clear Colourless Oil
• Application: α-Farnesene acts as an alarm pheromone in termites; also acts as a food attractants for the apple tree pest, the codling moth. α-Farnesene is also the chief compound contributing to the scent of gardenia, making up ~65% of the headspace constituents.
• Storage: Amber Vial, Refrigerator, Under inert atmosphere

Case Study

Olfactory orientation to α-farnesene in adult codling moths

Hern, Alan, and Silvia Dorn. Entomologia Experimentalis et Applicata 92.1 (1999): 63-72.

Little is known about the role of host plant-derived volatiles on the behavior of adult codling moths, Cydia pomonella L. The responses of females and males to a range of α-farnesene doses were tested. Natural α-farnesene in apples contains different ratios of E,E and Z,E isomers. No differences were found in the responses of codling moths to preparations containing two different ratios of E,E and Z,E isomers (77:20.7 or 1.2:84.7% for E,E and Z,E isomers, respectively), indicating similar biological activities of E,E and Z,E α-farnesenes against codling moths. Clear sexual dimorphism was found with increasing α-farnesene doses. Females were attracted to low doses and repelled by high doses. The dose response in this concentration range was linear with a negative slope. The responses of mated females and virgins were similar in kind but different in magnitude, with attraction and repulsion being more pronounced in mated females. Males were neither attracted nor repulsed over a wide range of doses, except for the highest dose which was attractive. This suggests that females have a stronger reliance on plant-derived volatiles.
On the day of use, dilutions for each set of bioassays were prepared from α-farnesene standards (stored at 4°C) and the concentrations of the dilutions were confirmed by gas chromatography analysis (average of three injections). The error margin for the preparation of the dilutions was set to ± 5% of the E,E-α-farnesene concentration. The total dose of α-farnesene was calculated based on the concentration of the E,E α-farnesene isomer, e.g., 50 ng E,E-α-farnesene/μl corresponds to a total α-farnesene concentration of 63.4 ng μl. In addition, the release rate of α-farnesene was evaluated for each dose. The olfactometer was set up as described previously, and a septum with added α-farnesene was placed in each arm of the olfactometer. After 15 minutes, the septum was removed and washed with 100 μl of hexane, and the resulting wash was injected into a gas chromatograph to measure the amount of E,E-α-farnesene. This process was repeated 3 times for each α-farnesene dose. These measurements were used to calculate the odor release rate of α-farnesene for each dose. The results showed that there was a linear relationship between the applied dose and the amount of E,E-α-farnesene recovered (r = 0.976; ANOVA F = 164.2; DF = 1,5; P < 0.001).

Quantification of α-farnesene in apple peel

Whitaker, Bruce D., Theophanes Solomos, and Dawn J. Harrison. Journal of Agricultural and Food Chemistry 45.3 (1997): 760-765.

The conjugated triene oxidation products of the sesquiterpene R-farnesene are thought to induce the occurrence of storage-disordered superficial scald. A C-HPLC method was designed that allows the simultaneous quantification of R-farnesene and its major oxidation products (conjugated triene alcohols) in hexane extracts of apple peel using UV detection at 232 and 269 nm. The identification of the compounds was confirmed by UV spectroscopy, HPLC with diode array detection, and GC-MS. Apples with high, medium, and low scald sensitivity were stored at 0°C in 1.5%, 3%, or 100% oxygen or air for up to 6 months. Peel samples were analyzed for R-farnesene and conjugated triene alcohol content, which correlated well with scald sensitivity and incidence. Storage under low oxygen conditions (1.5 or 3%) reduced farnesene and triene alcohol levels in each variety. There was a significant difference in farnesene and trienol production between two batches of RD fruit harvested 1 week apart; the earlier harvested fruit had higher levels of both and scalded, whereas the later harvested fruit did not scald. These results support the view that scald sensitivity of apple cultivars is a function of farnesene production and its oxidation to conjugated trienols.
Frozen peel tissue (10 g) of fruits stored in air at 0°C for 6 months was freeze-dried for 16 h, crushed, and extracted with 20 mL of hexane for 1 h at 5°C in a natural atmosphere. The extract was concentrated to 2 mL by N2 evaporation and then kept at -80 °C for 2 h to precipitate most of the waxes. After centrifugation for 2 min, the extract was decanted and then fractionated on a small pipette column. The column was washed with 2,2,4-trimethylpentane, hexane extracts were applied, and then the column was eluted sequentially with hexane (6 mL), hexane/diethyl ether (20:1, 8 mL), and hexane/diethyl ether (20:1, 8 mL). UV spectroscopy showed that all R-farnesene was in the hexane eluate (single absorbance maximum at 232 nm), while most of the conjugated triene was in the hexane/diethyl ether (8:1) eluate (absorbance maxima 259, 269, and 281 nm). After evaporation of the solvent under nitrogen, aliquots of these farnesene- and conjugated triene-enriched fractions were dissolved in methanol and subjected to HPLC analysis with diode array detection.

Prevention of superficial scald and α-Farnesene in pears

Isidoro, Nelson, and Domingos PF Almeida. Postharvest biology and technology 42.1 (2006): 49-56.

Diphenylamine (DPA) has been used for decades to prevent superficial scald, but the presence of DPA residues and the need for safer fruit necessitate the search for alternative strategies to control superficial scald. The effects of DPA and 1-methylcyclopropene (1-MCP) on α-farnesene and conjugated trienol levels in 'Rocha' pears were investigated and related to the development of superficial scald. α-Farnesene levels in fruit treated with DPA were similar or higher than untreated controls throughout storage, but the production of conjugated trienols from α-farnesene oxidation was reduced by DPA treatment. 1-MCP was highly effective in reducing scald. 0.1 l 1-MCP was as effective as DPA in reducing scald and had no effect on fruit ripening after a storage period of 4 months. At 0.5 or 1.0 l l, 1-MCP nearly eliminated superficial scald and delayed ripening after storage. We conclude that 1-MCP can replace DPA as a postharvest treatment to control scald in 'Rocha' pears, although relatively high concentrations delayed ripening after storage.
Fruits stored at 0°C were removed periodically over a period of 207 days and analyzed. Extraction and analysis of α-farnesene and conjugated trienols were performed as described, with modifications. Five fruits from the equatorial region on both sides of the peel were removed. After carefully scraping away all cortical tissue, 10 mm diameter disks were cut from the peel. Two disks cut from each fruit were immersed in 5 ml of hexane and incubated at 22°C for 10 min with stirring. After incubation, the solvent was filtered through a cellulose paper filter and the final volume was adjusted to 5 ml. Immediately after filtration, the absorbance of the extract was measured using a UV-visible spectrophotometer at 232 nm and in the range of 281-290 nm. The concentrations of α-farnesene and conjugated trienols were calculated using the molar extinction coefficients of ε = 27,740 for α-farnesene and ε = 25,000 for conjugated trienols (Anet, 1972) and expressed as g on a fresh weight basis.

Oxidation of α-farnesene and its inhibition by diphenylamine

Huelin, F. E., and I. M. Coggiola. Journal of the Science of Food and Agriculture 21.1 (1970): 44-48.

More α-farnesene was found in early-picked apples, which were more susceptible to scalding than late-picked apples, and in scalding-prone green apples than in scalding-resistant varieties. Further evidence for the movement of α-farnesene from fruit to oil-coated packaging is provided. The oxidation of α-farnesene in hexane solutions and in the natural coating of fruit is presented, as well as the inhibition of this oxidation by diphenylamine. This suggests that the oxidation products are the direct cause of scalding.
Solutions of (a) 6-48 mg α-farnesene, (b) 1-28 mg diphenylamine, and (c) 6.42 mg α-farnesene and 1.28 mg diphenylamine per liter were prepared in hexane. 10 ml aliquots of these solutions were transferred into test tubes, which were sealed to leave 10 ml headspace above the solutions. The headspace of half the tubes contained air and the other half contained carbon dioxide. A second set of tubes containing solutions of slightly different concentrations is prepared: per liter (a) 5.92 mg α-farnesene, (b) 118 mg diphenylamine, and (c) 5.86 mg α-farnesene and 118 mg diphenylamine. The tubes are stored at 20" and 37" without agitation and opened at regular intervals for analysis. The absorbance is recorded from 215-360 nm in a 1 cm cell. The absorbance of the α-farnesene solution containing diphenylamine is corrected by subtracting the absorbance of diphenylamine.