2-Methyl-4-heptanol

• CAS: 21570-35-4
• Catalog Number: ACM21570354
• Category: Main Products
• Molecular Weight: 130.23
• Molecular Formula: C8H18O
• Synonyms: 2-Methylheptan-4-ol
• Appearance: Colourless liquid

Case Study

Aggregation Pheromonal, Electrophysiological Stimulatory and Host Kairomone Synergistic Properties of 2-Methyl-4-heptanol

Palanichamy S, Padmanaban B, Mayil Vaganan M, et al. Current Science, 2019, 116(10): 1753-1757.

The semiochemical functions and olfactory stimulation characteristics of 2-methyl-4-heptanol (2M4H), the male-produced aggregation pheromone of banana pseudostem weevil (Odoiporus longicollis), were studied via electroantennogram (EAG) peripheral nerve detection and Y-tube olfactory behavioural bioassays. Its aliphatic alcohol carbon skeleton acts as the core pheromonal signal compound that triggers conspecific aggregation behaviour, and its olfactory activity can be significantly amplified by host plant kairomone extracts (HPE) from susceptible banana cultivar Nendran.
2-Methyl-4-heptanol exhibited distinct sex-specific electrophysiological stimulatory activity on weevil antennae: Serial log gradient dilution screening confirmed log 3 concentration as the optimal stimulus dose for clear sexual response differentiation; When applied alone as olfactory stimulus, male weevils generated average EAG amplitude of 2.473 mV, while female antennae only recorded 1.994 mV, both far higher than hexane blank control (0.221 mV male / 0.328 mV female). It demonstrated prominent synergistic olfactory attraction effects when combined with banana pseudostem host plant extract (HPE): The binary mixture of 2M4H and 10 μL optimum-dose HPE induced a peak male EAG response of 4.089 mV, representing a 65.4% increase relative to pure 2M4H treatment, and female EAG value rose to 3.249 mV (63.0% elevation vs single pheromone group). Additionally, 2-methyl-4-heptanol displayed strong conspecific aggregation-inducing behavioural properties in Y-tube olfactometer trials: Single 2M4 lure achieved male olfactory preference of 29.47% and female preference of 24.83%; after blending with HPE, male preference surged to 64.21% and female preference reached 55.47%, showing the composite lure greatly outperformed isolated pheromone or host volatile treatment. Behavioural activity statistics showed no significant sexual difference in total movement activity toward the 2M4H+HPE blend (male 68.49%, female 69.77), while pure 2M4H produced obvious gender divergence in weevil mobility. These studies demonstrate that 2-methyl-4-heptanol possesses key aggregation pheromone, dose-dependent electrophysiological stimulatory and host kairomone synergistic attractant properties for banana pseudostem weevil monitoring traps.
The olfactory stimulation and behavioural evaluation experiment was separated into EAG electrophysiology test batches and Y-tube behavioural assay groups. Laboratory-reared adult banana pseudostem weevils were divided into male and female cohorts with uniform rearing conditions (25±1 °C, 12 h light/dark cycle, 65-70% RH). Four olfactory treatments were set: hexane solvent blank control, single 2M4H, single HPE, and 2M4H+HPE composite lure; 2M4H was diluted into five log concentration gradients to screen optimum stimulation dose, HPE was set at 1-200 μL dose series for optimization. For EAG detection, weevil antennae were fixed with conductive spectral gel, humidified filtered air continuously flushed the antenna surface, each stimulus was tested six times with 3 min recovery intervals between stimulations, and absolute EAG millivolt amplitudes were recorded. For Y-tube bioassays, 20 replicate groups of five weevils each were tested per treatment; air flow rate maintained 250 mL/min, filter papers loaded with 10 μL test odour solvent were placed in two arms, weevil movement and directional choice were counted within 5 min release windows, and the olfactometer was rotated 180° to eliminate positional bias. Two-way ANOVA and LSD multiple comparison analysis were applied to compare EAG amplitude, activity percentage and preference percentage differences between sexes and treatment groups at α=0.05 significance threshold. The results verified that 2-methyl-4-heptanol functions as the core aggregation signal of O. longicollis, and host banana pseudostem volatiles generate strong synergism to strengthen antennal nerve response and host-seeking aggregation behaviour of both male and female weevils.

Aggregation Pheromonal, Electroantennal Stimulatory and Field Trapping Attractive Properties of 2-Methyl-4-heptanol

Ruiz-Montiel C, Cruz-López L, del Real I, et al. Entomologia Experimentalis et Applicata, 2008, 127: 207-217.

The semiochemical functions and olfactory bioactivity of 2-methyl-4-heptanol (2M4H), a male-released volatile alcohol component of agave weevil Scyphophorus acupunctatus aggregation pheromone blend, were characterized via GC-EAD electrophysiological detection, Y-tube laboratory olfactory bioassays and field trapping population monitoring trials. This chiral branched aliphatic alcohol is one of four male-specific antennal-active volatiles, together with 2-methyl-4-octanol, 2-methyl-4-heptanone and 2-methyl-4-octanone, jointly mediating conspecific aggregation behaviour of both male and female agave weevils.
2-Methyl-4-heptanol exhibited distinct dose-dependent electroantennal stimulatory activity on weevil antennae: Serial gradient stimulus loading tests confirmed 0.1 μg as the minimum threshold concentration triggering detectable antennal signals, lower than the 0.01 μg threshold of octanol/octanone analogues; Under standardized 10 μg stimulus dose, male antennae generated average EAG amplitude of 0.20 mV, while female antennae produced a higher mean response of 0.48 mV, with all 2M4H stimulus groups showing significantly elevated nerve signals compared to hexane solvent blank control. It demonstrated consistent cross-sex olfactory attraction capacity in laboratory Y-tube behavioural trials: When 10 ng synthetic 2M4H was loaded as odour stimulus, female weevils recorded 77.2% directional preference toward the pheromone arm, and male individuals reached 74.1% preference rate, both far exceeding the random 20-28% selection ratio of blank solvent control arms. Additionally, 2-methyl-4-heptanol displayed reliable field trapping performance when deployed alone or in composite pheromone blends: Single-component traps baited with sustained-release 2M4 captured an average of 0.51 weevils per trap per day in agave plantations; binary blend pairing 2M4H with 2-methyl-4-octanone further raised daily capture quantity to 1.89 weevils, and quaternary four-component mixture containing 2M4H achieved the highest field trapping efficiency at 1.01 weevils per trap daily, significantly outforming traps baited only with live male weevils or raw agave host plant material. Field population statistics revealed traps containing 2M4H captured 62-68% female individuals, supporting its critical function in recruiting ovipositing females for mass trapping integrated pest management. GC-EAD chromatogram profiling verified 2M4H elicits consistent repeatable antennal depolarization signals independent of weevil sex, confirming its conserved semiochemical recognition pathway across genders. These studies demonstrate that 2-methyl-4-heptanol possesses core aggregation pheromone, dose-responsive electrophysiological stimulation and field-usable trapping attractive properties for sustainable agave weevil population suppression.
The semiochemical evaluation experiment was separated into GC-EAD electrophysiological batches, Y-tube laboratory behavioural groups and agave plantation field trapping trials. For electrophysiology assays, excised male and female weevil antennae were fixed with Ringer solution electrodes, serial 0.0001-10 μg dilutions of synthetic 2M4H in hexane were sequentially pulsed at 1 min intervals, EAG millivolt amplitudes recorded and two-way ANOVA applied with dose and sex as independent factors. For olfactometer bioassays, single adult weevil was released per 5 min trial period, odour arms loaded with 10 ng 2M4H or pure hexane control, test position reversed after each replicate to eliminate directional bias, 40 replicates conducted per sex for statistical counting of directional preference percentage. Field trapping experiments adopted randomized complete block layout in 5-year-old Agave tequilana plantations; treatments included blank empty trap, agave plant bait, live male weevil lure, single 2M4H, binary/ternary/quaternary pheromone blends incorporating 2M4H, traps fitted with slow-release microtube dispensers and insecticidal agave baits inside capture buckets, daily weevil counts recorded over 15-day continuous sampling cycles, Tukey HSD multiple comparison test used to separate mean capture differences across all lure treatments at α=0.05 significance threshold. The results verified 2-methyl-4-heptanol acts as an indispensable minor aggregation pheromone component of S. acupunctatus, capable of standalone conspecific attraction and synergistic population trapping enhancement when mixed with ketone pheromone analogues under field conditions.

Chiral Resolution, Diastereomer Separation and NMR Anisotropic Characterization Properties of 2-Methyl-4-heptanol

Ichikawa A, Ono H. Journal of Chromatography A, 2006, 1117: 38-46.

The chiral structural features and stereochemical analytical performance of racemic 2-methyl-4-heptanol (RS-2M4H), a key aggregation pheromone component of Metamasius hemipterus weevils, were studied via diastereomeric ester derivatization, silica gel HPLC separation and high-field NMR anisotropy analysis. Its chiral secondary alcohol carbon skeleton creates distinct stereoisomeric configurations, and single-enantiomer MNP acid [(S)-2-methoxy-2-(1-naphthyl)propionic acid] acts as superior resolving reagent to split racemic 2M4H into pure (R) and (S) enantiomers.
2-Methyl-4-heptanol exhibited clear diastereomeric differentiation capacity after esterification with chiral MNP acid: Racemic RS-2M4H reacted with enantiopure (S)-MNP acid under EDC/DMAP catalysis to generate two separable diastereomeric MNP esters (S,R)-13 and (S,S)-14 at total 86% synthetic yield; silica gel HPLC with n-hexane/THF mobile phase achieved resolution factor α=1.09 and resolution value Rs=2.28, far superior to MTP acid derivatization groups which produced fully overlapping chromatographic peaks without separation. It demonstrated distinguishable NMR anisotropy signals for stereochemical assignment: The chemical shift difference (Δδ) values of aliphatic proton signals between two MNP diastereomers reached 0.3-0.6 ppm on alkyl side chains, which were 3-6 times larger than Δδ values of MTPA ester derivatives, enabling unambiguous absolute configuration confirmation of (R)- and (S)-2M4H without auxiliary authentic standards. Additionally, 2-methyl-4-heptanol single enantiomers could be quantitatively recovered via mild alkaline solvolysis of purified MNP esters: Solvolysis of (S,R)-13 afforded enantiopure (R)-2M4H at 76% recovery rate ([α]D²⁷ = -12), while hydrolysis of (S,S)-14 yielded pure (S)-2M4H at 85% yield ([α]D²⁷ = +13), and over 44% of the expensive chiral MNP resolving acid was recycled simultaneously after acidification extraction. HPLC and LC-MS identification verified no racemization occurred during ester formation, chromatographic purification or solvolysis steps, as the quaternary chiral center of MNP acid remained structurally stable under all reaction conditions. These studies demonstrate that 2-methyl-4-heptanol possesses distinct chiral resolution, high-efficiency diastereomer separation and NMR-detectable stereochemical characterization properties when paired with MNP acid derivatization.
The stereochemical resolution and characterization experiment was split into derivatization batches, HPLC separation groups and solvolysis recovery test groups. For derivatization, racemic 2-methyl-4-heptanol was mixed with >99% ee (S)-MNP acid, EDC coupling reagent and DMAP catalyst in dichloromethane, stirred 19 h at ambient temperature to form diastereomeric ester mixtures; parallel control groups adopted (R)-MTPA acid for comparative derivatization. Silica gel SG80 HPLC columns were used for diastereomer purification, with two mobile phase systems (n-hexane/EtOAc and n-hexane/THF) tested to compare separation efficiency, UV detection set at 300 nm for naphthyl absorbance tracking. Purified single diastereomers underwent NaOMe/MeOH reflux solvolysis for 6 h under argon protection, followed by dichloromethane extraction to isolate enantiomeric 2M4H; aqueous acid layer was recovered to regenerate raw MNP acid. 500/800 MHz ¹H and ¹³C NMR spectrometers recorded all ester spectral data to calculate Δδ anisotropy values, optical rotation polarimeter measured specific rotation of pure (R)/(S)-2M4H enantiomers. One-way ANOVA was applied to compare chromatographic resolution parameters and solvolysis recovery yields across different resolving acid systems at α=0.05 significance threshold. The results verified that the chiral secondary alcohol structure of 2-methyl-4-heptanol forms well-resolved diastereomeric adducts with MNP acid, allowing complete separation, stereochemical assignment and high-yield recovery of single pheromone enantiomers for subsequent insect bioactivity testing.

Electrophysiological Active, Synergistic Aggregation and Geographical Strain-Specific Pheromone Properties of 2-Methyl-4-heptanol

Giblin-Davis R M, Gries R, Crespi B, et al. Journal of Chemical Ecology, 2000, 26(12): 2763-2780.

The semiochemical functions and strain-specific pheromone performance of 2-methyl-4-heptanol (2M4H), a male-produced aliphatic alcohol volatile, were characterized via GC-EAD antennal electrophysiology, laboratory olfactory assays and multi-site sugarcane field trapping trials targeting Rhabdoscelus obscurus (New Guinea sugarcane weevil). This compound is one of three male-specific EAD-active volatiles secreted by Australian populations of the weevil, while it is absent in the pheromone profile of Hawaiian conspecific isolates, creating divergent inter-population chemical communication phenotypes.
2-Methyl-4-heptanol exhibited distinct electrophysiological stimulatory activity on both male and female weevil antennae: GC-EAD chromatographic analysis of volatile extracts from Australian male weevils generated clear, reproducible antennal depolarization signals at the retention time matching synthetic 2M4H, with average EAG response amplitude reaching 0.4 mV, while no corresponding EAD peak was detected from Hawaiian male volatile collections. It demonstrated powerful synergistic aggregation effects only when blended with the core pheromone components 2-methyl-4-octanol and rhynchophorol against Australian R. obscurus strains: Field traps baited with the ternary mixture (2M4H + 2-methyl-4-octanol + rhynchophorol, 3 mg/day each) plus sugarcane host material captured 212 weevils per trap over two weeks, whereas traps loaded with 2-methyl-4-octanol and rhynchophorol without 2M4H only caught 146 individuals, representing a 45% capture boost attributed to 2M4H synergism. Additionally, 2-methyl-4-heptanol displayed strain-specific behavioural irrelevance for Hawaiian weevil populations: In Hawaii field trials, traps containing pure 2M4H plus sugarcane recorded equivalent low weevil counts as blank sugarcane control traps, with no statistically significant increase in male or female attraction, confirming Hawaiian weevils lack olfactory receptor pathways to detect this semiochemical. Sex ratio statistics revealed ternary pheromone blends containing 2M4H attracted slightly more female weevils (1.4 females per male) than single-component baits, indicating 2M4H enhances female recruitment to aggregation sites. GC-MS mass spectrum matching validated identical molecular ion peaks between synthetic standard and native male weevil volatile extracts, confirming 2M4H as an authentic male secretion product exclusive to Australian geographical isolates. These studies demonstrate that 2-methyl-4-heptanol possesses significant antennal electrophysiological activity, host-pheromone synergistic aggregation function and geographical strain-selective semiochemical specificity for sugarcane weevil pest monitoring.
The semiochemical evaluation experiment was separated into GC-EAD electrophysiology batches, Australian sugarcane field trapping groups and Hawaiian island field validation trials. For volatile collection, 30+ mature male/female weevils from each geographical isolate were confined with apple feed, and volatiles were trapped on Porap Q adsorbent then eluted with pentane for GC-EAD/GC-MS analysis; excised adult weevil antennae were mounted on Syntech EAD electrodes to record nerve depolarization responses to separated volatile peaks. Field trapping experiments adopted randomized complete block designs, with six standardized lure treatments: unbaited blank, sugarcane only, single 2-methyl-4-octanol, binary 2-methyl-4-octanol + rhynchophorol, ternary blend including 2M4H, and single 2M4H lure, all supplemented with fresh sugarcane host tissue as kairomone matrix. Polymer membrane release dispensers delivered each synthetic pheromone at a constant 3 mg/day emission rate, and lethal bucket traps with detergent drowning solution were deployed 30 m apart across sugarcane plantations; weekly weevil counts were recorded, separated by sex, over multi-week sampling cycles. One-way ANOVA and LSD multiple comparison tests were applied to analyze mean trap capture differences across all lure treatments and geographical populations at α=0.05 significance threshold. The results verified that 2-methyl-4-heptanol acts as a secondary synergistic aggregation pheromone component unique to Australian Rhabdoscelus obscurus males, exerting additive attractant effects only in multi-component pheromone blends and exhibiting no behavioural activity in Hawaiian conspecific weevil populations.

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August 07, 2023

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Custom Q&A

What is the molecular formula of 2-methyl-4-heptanol?

The molecular formula of 2-methyl-4-heptanol is C8H18O.

What is the molecular weight of 2-methyl-4-heptanol?

The molecular weight of 2-methyl-4-heptanol is 130.23 g/mol.

Can you provide any synonyms for 2-methyl-4-heptanol?

Some synonyms for 2-methyl-4-heptanol are 2-Methylheptan-4-ol and 4-Heptanol, 2-methyl-.

What is the IUPAC name of 2-methyl-4-heptanol?

The IUPAC name of 2-methyl-4-heptanol is 2-methylheptan-4-ol.

What is the InChI of 2-methyl-4-heptanol?

The InChI of 2-methyl-4-heptanol is InChI=1S/C8H18O/c1-4-5-8(9)6-7(2)3/h7-9H,4-6H2,1-3H3.

What is the InChIKey of 2-methyl-4-heptanol?

The InChIKey of 2-methyl-4-heptanol is QXPLZEKPCGUWEM-UHFFFAOYSA-N.

What is the canonical SMILES of 2-methyl-4-heptanol?

The canonical SMILES of 2-methyl-4-heptanol is CCCC(CC(C)C)O.

What is the CAS number of 2-methyl-4-heptanol?

The CAS number of 2-methyl-4-heptanol is 21570-35-4.

What is the European Community (EC) number of 2-methyl-4-heptanol?

The European Community (EC) number of 2-methyl-4-heptanol is 244-448-7.

What is the XLogP3-AA value of 2-methyl-4-heptanol?

The XLogP3-AA value of 2-methyl-4-heptanol is 2.5.