Functional Characterisation of Highly Conserved and Structurally Prominent Residues of 2-Methylisoborneol Synthase.

2-Methylisoborneol is a widespread musty odourant that is produced by many bacteria including actinomycetes, cyanobacteria and myxobacteria. Two 2-methylisoborneol synthases (MIBS) that are phylogenetically distant to the known enzyme from Streptomyces coelicolor were found to be highly active for 2-methylisoborneol biosynthesis. Based on the enzyme structure and on an amino acid sequence alignment, the MIBS from S. coelicolor was extensively studied through site-directed mutagenesis.

Microbial Degradation of 2-Methylisoborneol in Forest Soil.

Microorganisms use a complex array of chemical compounds to interact with their surroundings. They produce and process different molecules in response to changes in the environment or in their metabolism. One of the most well-known volatile organic compounds produced by microorganisms is the C11-terpenoid 2-methylisoborneol (2-MIB), which has received attention because of the off-flavor it confers to fresh and reservoir water as well as to cultured fish. Cleaning water supplies of the off-flavor 2-MIB has been of interest for the scientific community for years, with the use of techniques that are either expensive, e. g., activated carbon, or create toxic byproducts, e. g., ozonation. In the present study, soil samples from nature were collected from a forest and the volatile organic compounds produced by microbes were extracted and analyzed with focus on non-canonical terpenoid structures. HS-SPME-GC/MS analysis of soil samples revealed 1-methylcamphene (1-MC), 2-methylenebornane (2-MB) and 2-MIB as C11-terpenoids. Due to the high 1-MC/2-MIB ratio compared to previous reports, it was hypothesized that microbial degradation of 2-MIB was in place. Addition of synthetic 2-MIB to biologically active soil revealed complete degradation of the pollutant to 2-MB, 1-MC and 2-methyl-2-bornene (2-M2B). The results suggest the potential of using respective natural microorganisms for biodegradation of 2-MIB, with applications in water treatment, fishery and soil ecology.

Fenchone Derivatives as a Novel Class of CB2 Selective Ligands: Design, Synthesis, X-ray Structure and Therapeutic Potential.

A series of novel cannabinoid-type derivatives were synthesized by the coupling of (1S,4R)-(+) and (1R,4S)-(-)-fenchones with various resorcinols/phenols. The fenchone-resorcinol derivatives were fluorinated using Selectfluor and demethylated using sodium ethanethiolate in dimethylformamide (DMF). The absolute configurations of four compounds were determined by X-ray single crystal diffraction. The fenchone-resorcinol analogs possessed high affinity and selectivity for the CB2 cannabinoid receptor. One of the analogues synthesized, 2-(2',6'-dimethoxy-4'-(2″-methyloctan-2″-yl)phenyl)-1,3,3-trimethylbicyclo[2.2.1]heptan-2-ol (1d), had a high affinity (Ki = 3.51 nM) and selectivity for the human CB2 receptor (hCB2). In the [35S]GTPγS binding assay, our lead compound was found to be a highly potent and efficacious hCB2 receptor agonist (EC50 = 2.59 nM, E(max) = 89.6%). Two of the fenchone derivatives were found to possess anti-inflammatory and analgesic properties. Molecular-modeling studies elucidated the binding interactions of 1d within the CB2 binding site.

In Silico and Ex Vivo Studies on the Spasmolytic Activities of Fenchone Using Isolated Guinea Pig Trachea.

Fenchone is a bicyclic monoterpene found in a variety of aromatic plants, including Foeniculum vulgare and Peumus boldus, and is used in the management of airways disorders. This study aimed to explore the bronchodilator effect of fenchone using guinea pig tracheal muscles as an ex vivo model and in silico studies. A concentration-mediated tracheal relaxant effect of fenchone was evaluated using isolated guinea pig trachea mounted in an organ bath provided with physiological conditions. Sustained contractions were achieved using low K+ (25 mM), high K+ (80 mM), and carbamylcholine (CCh; 1 µM), and fenchone inhibitory concentration-response curves (CRCs) were obtained against these contractions. Fenchone selectively inhibited with higher potency contractions evoked by low K+ compared to high K+ with resultant EC50 values of 0.62 mg/mL (0.58-0.72; n = 5) and 6.44 mg/mL (5.86-7.32; n = 5), respectively. Verapamil (VRP) inhibited both low and high K+ contractions at similar concentrations. Pre-incubation of the tracheal tissues with K+ channel blockers such as glibenclamide (Gb), 4-aminopyridine (4-AP), and tetraethylammonium (TEA) significantly shifted the inhibitory CRCs of fenchone to the right towards higher doses. Fenchone also inhibited CCh-mediated contractions at comparable potency to its effect against high K+ [6.28 mg/mL (5.88-6.42, n = 4); CCh] and [6.44 mg/mL (5.86-7.32; n = 5); high K+]. A similar pattern was obtained with papaverine (PPV), a phosphodiesterase (PDE), and Ca2+ inhibitor which inhibited both CCh and high K+ at similar concentrations [10.46 µM (9.82-11.22, n = 4); CCh] and [10.28 µM (9.18-11.36; n = 5); high K+]. However, verapamil, a standard Ca2+ channel blocker, showed selectively higher potency against high K+ compared to CCh-mediated contractions with respective EC50 values of 0.84 mg/mL (0.82-0.96; n = 5) 14.46 mg/mL (12.24-16.38, n = 4). The PDE-inhibitory action of fenchone was further confirmed when its pre-incubation at 3 and 5 mg/mL potentiated and shifted the isoprenaline inhibitory CRCs towards the left, similar to papaverine, whereas the Ca2+ inhibitory-like action of fenchone pretreated tracheal tissues were authenticated by the rightward shift of Ca2+ CRCs with suppression of maximum response, similar to verapamil, a standard Ca2+ channel blocker. Fenchone showed a spasmolytic effect in isolated trachea mediated predominantly by K+ channel activation followed by dual inhibition of PDE and Ca2+ channels. Further in silico molecular docking studies provided the insight for binding of fenchone with Ca2+ channel (-5.3 kcal/mol) and K+ channel (-5.7), which also endorsed the idea of dual inhibition.

Design, synthesis, fungicidal activities and structure-activity relationship studies of (-)-borneol derivatives containing 2-aryl-thiazole scaffold.

A series of (-)-borneol derivatives containing 2-aryl-thiazole scaffold were designed, synthesized, and characterized by 1H NMR, 13C NMR, and HRMS. The fungicidal activities of these novel compounds against Fusarium oxysporum, Magnaporthe grisea, Botrytis cinerea, and Penicillium digitatum were evaluated. The results indicated that (1S,2R,4S)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl(Z)-4-oxo-4-(((2-phenylthiazol-4-yl)methyl)amino)but-2-enoate (6a) displayed potential fungicidal activities with broad spectrum. Especially, 6a exhibited an IC50 value of 48.5 mg/L against P. digitatum, which has higher fungicidal activity than commercial products hymexazol and amicarthiazol. Moreover, (1S,2R,4S)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl-4-oxo-4-(((2-phenylthiazol-4-yl)methyl)amino)butanoate (5a) possesses an IC50 value of 24.3 mg/L against B. cinerea, comparable to hymexazol and far superior to amicarthiazol. Furthermore, the superficial structure-activity relationship was discussed, which might be helpful for discovering novel fungicides.

(+)-Camphor and (-)-borneol derivatives as potential anti-orthopoxvirus agents.

Although the World Health Organisation had announced that smallpox was eradicated over 40 years ago, the disease and other related pathogenic poxviruses such as monkeypox remain potential bioterrorist weapons and could also re-emerge as natural infections. We have previously reported (+)-camphor and (-)-borneol derivatives with an antiviral activity against the vaccinia virus. This virus is similar to the variola virus (VARV), the causative agent of smallpox, but can be studied at BSL-2 facilities. In the present study, we evaluated the antiviral activity of the most potent compounds against VARV, cowpox virus, and ectromelia virus (ECTV). Among the compounds tested, 4-bromo-N'-((1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene)benzohydrazide 18 is the most effective compound against various orthopoxviruses, including VARV, with an EC50 value of 13.9 µM and a selectivity index of 206. Also, (+)-camphor thiosemicarbazone 9 was found to be active against VARV and ECTV.

Hydrogen Delocalization in an Asymmetric Biomolecule: The Curious Case of Alpha-Fenchol.

Rotational microwave jet spectroscopy studies of the monoterpenol α-fenchol have so far failed to identify its second most stable torsional conformer, despite computational predictions that it is only very slightly higher in energy than the global minimum. Vibrational FTIR and Raman jet spectroscopy investigations reveal unusually complex OH and OD stretching spectra compared to other alcohols. Via modeling of the torsional states, observed spectral splittings are explained by delocalization of the hydroxy hydrogen atom through quantum tunneling between the two non-equivalent but accidentally near-degenerate conformers separated by a low and narrow barrier. The energy differences between the torsional states are determined to be only 16(1) and 7(1) cm-1hc for the protiated and deuterated alcohol, respectively, which further shrink to 9(1) and 3(1) cm-1hc upon OH or OD stretch excitation. Comparisons are made with the more strongly asymmetric monoterpenols borneol and isopinocampheol as well as with the symmetric, rapidly tunneling propargyl alcohol. In addition, the third-in contrast localized-torsional conformer and the most stable dimer are assigned for α-fenchol, as well as the two most stable dimers for propargyl alcohol.

Appraisal of hypotensive effect of natural monoterpene: Bornyl acetate and in-silico molecular docking analysis.

The modern trend of research is highly focused on finding new bioactive molecules from medicinal plants. As a functional bicyclic monoterpene, Bornyl acetate (BA) has displayed antioxidant and anti-inflammatory properties in different types of cells and tissues. The purpose of this research was to evaluate the probable hypotensive effect of BA, an underlying mechanism(s) backboned by in-silico studies. Mean arterial pressure and heart rate were recorded via invasive blood pressure measuring technique in normotensive Sprague-Dawley rats following the administration of BA (1-80mg/kg). Docking studies were carried out with various targets involved in the pathophysiology of hypertension.RO5 and ADMET properties were also evaluated. In the current study dose-dependent reduction in systolic, diastolic and mean arterial pressure was observed. Pretreatment with atropine and captopril significantly (p<0.001) reduced the hypotensive effect produced by BA. On the other hand docking studies showed pronounced interactions with M2 mAch receptor in an agonistic way and ACE protein in an antagonistic way. BA justified all cut-off limits of RO5 and had an acceptable predicted computational toxicity profile. Results postulate that dose-dependent hypotensive effect of BA is mediated through the muscarinic pathway and ACE inhibitory activity corresponding well with findings of in-silico studies.

Contact toxicity and repellent efficacy of Valerianaceae spp. to three stored-product insects and synergistic interactions between two major compounds camphene and bornyl acetate.

In this work, the essential oil (EO) and supercritical CO2 fluid extract (SF extract) of four Valerianaceae plants (Valeriana officinalis L., Valeriana officinalis L. var. latifolia Miq., Valeriana jatamansi Jones and Nardostachys chinensis Bat.) were chemically characterized. GC-MS analysis identified 74 compounds, representing 35.2%-82.4% of the total EOs and SF extracts. The EO was dominated by low-molecular-weight components while the SF extract was rich in fatty acids. Bornyl acetate and camphene were the characteristic compounds in EO and SF extracts. The efficacy of six extracts against three stored-product insects was investigated. In contact assays, V. officinalis exhibited strongest toxicity to red flour beetle (LD50 = 10.0 µg/adult), and V. jatamansi EO was the most active one against the cigarette beetle (LD50 = 17.6 µg/adult), while V. officinalis var. latifolia EO showed outstanding efficacy against the booklouse (LD50 = 40.2 µg/cm2). Binary mixtures of two major compounds (camphene and bornyl acetate) were assessed for the contact toxicity to the red flour beetle. Additive effect existed in the natural proportion of V. officinalis, and synergism was observed in that of V. officinalis var. latifolia. This work confirmed the insecticidal efficacy of the species of the Valerianaceae family, and it would offer some information for the development of botanical insecticide.

Potentiometric E-Tongue System for Geosmin/Isoborneol Presence Monitoring in Drinkable Water.

A potentiometric E-tongue system based on low-selective polymeric membrane and chalcogenide-glass electrodes is employed to monitor the taste-and-odor-causing pollutants, geosmin (GE) and 2-methyl-isoborneol (MIB), in drinkable water. The developed approach may permit a low-cost monitoring of these compounds in concentrations near the odor threshold concentrations (OTCs) of 20 ng/L. The experiments demonstrate the success of the E-tongue in combination with partial least squares (PLS) regression technique for the GE/MIB concentration prediction, showing also the possibility to discriminate tap water samples containing these compounds at two concentration levels: the same OTC order from 20 to 100 ng/L and at higher concentrations from 0.25 to 10 mg/L by means of PLS-discriminant analysis (DA) method. Based on the results, developed multisensory system can be considered a promising easy-to-handle tool for express evaluation of GE/MIB species and to provide a timely detection of alarm situations in case of extreme pollution before the drinkable water is delivered to end users.

Development and Evaluation of Controlled and Simultaneous Release of Compound Danshen Based on a Novel Colon-Specific Osmotic Pump Capsule.

In the study, we developed a novel oral dosage form of Compound Danshen to resolve the problems of low bioavailability, disequilibrium in drug release, and stomach degradation of active components of Compound Danshen in conventional formulas. A colon-specific osmotic pump capsule (COPC) of Compound Danshen was prepared using a semipermeable shell with the core components. Using a single-factor method, we obtained the optimal formulation that consisted of Salvia miltiorrhiza extract, Panax notoginseng extract, Borneol, sodium chloride, polyethylene oxide wsr-N10, hydroxypropyl-ß-cyclodextrin, and ludipress. Moreover, in vitro dissolution test showed simultaneous releases of active ingredients from Compound Danshen COPC over 12 h at pH 7.8, displaying zero-order release characteristics. The impetus of drug release mainly depended on the difference in osmotic pressure across the capsule shell. Next, scanning electron microscopy showed morphological changes in the capsule shell during the dissolution test. More importantly, pharmacokinetic study in beagle dogs indicated that relative bioavailability was 330.58% and retention time was greatly prolonged in Compound Danshen COPC, compared with those in marketed Compound Danshen tablet products. Finally, in vivo imaging studies in beagle dogs showed that COPC was stable in gastrointestinal tract and the drug was specifically released in the colon region. A colon-specific osmotic pump capsule (COPC) of Compound Danshen was developed and optimized to achieve simultaneous zero-order release of multiple active components of Compound Danshen in the colon. More importantly, the COPC have proved to improve the bioavailability and prolong the retention time of Compound Danshen, compared with those in a marketed product.

Cell Engineering with Functional Poly(oxanorbornene) Block Copolymers.

Cell-based therapies are gaining prominence in treating a wide variety of diseases and using synthetic polymers to manipulate these cells provides an opportunity to impart function that could not be achieved using solely genetic means. Herein, we describe the utility of functional block copolymers synthesized by ring-opening metathesis polymerization (ROMP) that can insert directly into the cell membrane via the incorporation of long alkyl chains into a short polymer block leading to non-covalent, hydrophobic interactions with the lipid bilayer. Furthermore, we demonstrate that these polymers can be imbued with advanced functionalities. A photosensitizer was incorporated into these polymers to enable spatially controlled cell death by the localized generation of 1 O2 at the cell surface in response to red-light irradiation. In a broader context, we believe our polymer insertion strategy could be used as a general methodology to impart functionality onto cell-surfaces.

Effect of esters based on terpenoids and GABA on fluidity of phospholipid membranes.

The influence of esters based on gamma-aminobutyric acid (GABA) and mono-/bicyclic terpenoids on membrane structure was investigated. The mechanism of action for terpenoid esters on phospholipids of artificial membranes and lipids isolated from the rat stratum corneum was studied by fluorescence and FT-IR spectroscopy. We report here, that inclusion of monocyclic terpenoid esters in phospholipid liposomes leads to growth of excimer to monomer ratio (IE/IM) indicating a decrease of membrane microviscosity. Another mechanism of influence on biomembranes was proposed for ester of bicyclic borneol - in this case a high ratio of vibronic peak intensities (I1/I3) was revealed. The addition of terpenoid esters appears in the FT-IR spectra as intensity reduction of absorption bands associated with C = O, P = O and P-O-С groups of lecithin phospholipids. Similar results were obtained after esters addition to lipids isolated from stratum corneum indicating a decrease of hydrogen bonds number between polar groups of lipids. Thus, the influence of terpenoid esters on molecular organization of the lipid matrix substantiates the feasibility of their use after transdermal delivery in vivo.

Synthesis and Antioxidant Ability of Novel Derivatives Based on para-Coumaric Acid Containing Isobornyl Groups.

A series of novel esters and amides was synthesized on the basis of para-coumaric acid containing isobornyl groups in ortho-positions relative to the phenolic hydroxy group. Antioxidant properties of the obtained compounds were evaluated and compared on in vitro models: radical-scavenging ability, antioxidant activity on a substrate containing the lipids of animal brain, cytotoxicity of red blood cells, antioxidant and membrane-protective properties on the model of oxidative red blood cells hemolysis. Statistically significant relationship was established between the antioxidant activity of the studied compounds in model system containing animal lipids and the parameters reflecting their antioxidant properties on the model of H2 O2 -induced hemolysis of red blood cells. It was determined that an amide with a morpholine fragment has the highest antioxidant activity. The specified derivative significantly surpassed the reference substances (parent acid, BHT) and was not inferior to the effective antioxidant 2,6-diisobornyl-4-methylphenol in terms of its properties.

In vivo microdialysis with ultra performance liquid chromatography-mass spectrometry for analysis of tetramethylpyrazine and its interaction with borneol in rat brain and blood.

Tetramethylpyrazine (TMP) has been widely used in the treatment of ischemic cerebrovascular disease. However, the mechanism of TMP and how to increase its bioavailability need to be further explored. In our study, an in vivo microdialysis sampling technique coupled with ultra-performance liquid chromatography-mass spectrometry method was developed to investigate the pharmacokinetic properties of TMP and its interaction with different doses of borneol (BO) in rats. Linearity of TMP in brain and blood dialysates exhibited good linear relationships over the concentration range of 0.991-555.14 ng/mL. The specificity, linearity, accuracy, precision, matrix effect and stability were within acceptable ranges. The results demonstrated that BO had a marked impact on the pharmacokinetic properties of TMP. After co-administration, the areas under the concentration-time curve (AUC) of TMP in brain and blood were significantly increased. Meanwhile, the peak concentration of TMP in brain was also enhanced. The AUCBrain /AUCBlood of TMP, increased from 44% to 56 and 60.8% after co-administration with BO (15 and 30 mg/kg). The pharmacodynamic results showed that TMP co-administration with BO enhanced the cerebral blood flow during the period of ischemia and reduced the infarct volume. Overall, it might be an effective way to treat stroke to use TMP co-administered with BO.

Discovery of a New Class of Inhibitors of Vaccinia Virus Based on (-)-Borneol from Abies sibirica and (+)-Camphor.

A series of the bornyl ester/amide derivatives with N-containing heterocycles were designed and synthesized as vaccinia virus (VV) inhibitors. Bioassay results showed that among the designed compounds, derivatives 6, 13, 14, 34, 36 and 37 showed the best inhibitory activity against VV with the IC50 values of 12.9, 17.9, 3.4, 2.5, 12.5 and 7.5 µm, respectively, and good cytotoxicity. The primary structure-activity relationship (SAR) study suggested that the combination of a saturated N-heterocycle, such as morpholine or 4-methylpiperidine, and a 1,7,7-trimethylbicyclo[2.2.1]heptane scaffold was favorable for antiviral activity.

Antiradical Activity of Porphyrins with a Diisobornylphenol Fragment at the Macrocycle Periphery.

This article focuses on the antiradical activity of a number of 2,6-diisobornylphenol-porphyrin conjugates with various spacers between the porphyrin and phenolic fragments in the model reaction of ethylbenzene oxidation initiated by azoisobutyric acid dinitrile. The study has shown that the electronic effects of the groups directly related to the 2,6-diisobornylphenol fragment exert the predominant influence both on the reactivity of the phenolic hydroxyl group in interaction with free radicals and on the antiradical activity of the molecule as a whole. The antiradical activity of the molecule is generally less affected by the nature of the substituents in the porphyrin macrocycle, mainly due to a change in the stoichiometric inhibition coefficient in the presence of relatively easily oxidizable groups. It was found that the length of the spacer between the porphyrin and phenolic fragments does not affect the antiradical activity of the conjugate.

Optimization of the Preparation Conditions of Borneol-Modified Ginkgolide Liposomes by Response Surface Methodology and Study of Their Blood Brain Barrier Permeability.

Ginkgolides (GG), containing ginkgolide A (GA), ginkgolide B (GB) and ginkgolide C (GC), are mainly prescribed for ischemic stroke and cerebral infarction. However, the ginkgolides can hardly pass the blood-brain barrier (BBB) into the brain. The purpose of this study was to prepare borneol-modified ginkgolides liposomes (GGB-LPs) to study whether borneol could enhance the transport of ginkgolides across the BBB. The preparation conditions of GGB-LPs were optimized by a response surface-central composite design. Also, pharmacokinetics and biodistribution studies of GGB-LPs were conducted using UPLC-MS. The optimal preparation conditions for GGB-LP were as follows: ratio of lipid to drug (w/w) was 9:1, ratio of phospholipid to cholesterol (w/w) was 7:1, and hydrate volume was 17.5 mL. Under these conditions, the GGB-LP yield was 89.73 ± 3.45%. With GGB-LPs, borneol significantly promoted the transport of ginkgolide across the BBB. The pharmacokinetic parameters of GGB-LP were significantly improved too, with Tmax of 15 min and a high drug concentration of 3.39 µg/g in brain. Additionally, the drug targeting index and relative uptake rate of GGB-LP was increased. Borneol-modified ginkgolide liposomes can thus potentially be used to improve the BBB permeability of gingkolide formulations.

DBZ is a putative PPARγ agonist that prevents high fat diet-induced obesity, insulin resistance and gut dysbiosis.

BACKGROUND: The nuclear receptor PPARγ is an effective pharmacological target for some types of metabolic syndrome, including obesity, diabetes, nonalcoholic fatty liver disease, and cardiovascular disease. However, the current PPARγ-targeting thiazolidinedione drugs have undesirable side effects. Danshensu Bingpian Zhi (DBZ), also known as tanshinol borneol ester derived from Salvia miltiorrhiza, is a synthetic derivative of natural compounds used in traditional Chinese medicine for its anti-inflammatory activity. METHODS: In vitro, investigations of DBZ using a luciferase reporter assay and molecular docking identified this compound as a novel promising PPARγ agonist. Ten-week-old C57BL/6J mice were fed either a normal chow diet (NCD) or a high-fat diet (HFD). The HFD-fed mice were gavaged daily with either vehicle or DBZ (50mg/kg or 100mg/kg) for 10weeks. The gut microbiota composition was assessed by analyzing the 16S rRNA gene V3+V4 regions via pyrosequencing. RESULTS: DBZ is an efficient natural PPARγ agonist that shows lower PPARγ-responsive luciferase reporter activity than thiazolidinediones, has excellent effects on the metabolic phenotype and exhibits no unwanted adverse effects in a HFD-induced obese mouse model. DBZ protects against HFD-induced body weight gain, insulin resistance, hepatic steatosis and inflammation in mice. DBZ not only stimulates brown adipose tissue (BAT) browning and maintains intestinal barrier integrity but also reverses HFD-induced intestinal microbiota dysbiosis. CONCLUSIONS: DBZ is a putative PPARγ agonist that prevents HFD-induced obesity-related metabolic syndrome and reverse gut dysbiosis. GENERAL SIGNIFICANCE: DBZ may be used as a beneficial probiotic agent to improve HFD-induced obesity-related metabolic syndrome in obese individuals.

Reliable HPLC separation, vibrational circular dichroism spectra, and absolute configurations of isoborneol enantiomers.

Resolution of chiral compounds has played an important role in the pharmaceutical field, involving detailed studies of pharmacokinetics, physiological, toxicological, and metabolic activities of enantiomers. Herein, a reliable method by high-performance liquid chromatography (HPLC) coupled with an optical rotation detector was developed to separate isoborneol enantiomers. A cellulose tris(3, 5-dimethylphenylcarbamate)-coated chiral stationary phase showed the best separation performance for isoborneol enantiomers in the normal phase among four polysaccharide chiral packings. The effects of alcoholic modifiers and column temperature were studied in detail. Resolution of the isoborneol racemate displayed a downward trend along with an increase in the content of ethanol and column temperature, indicating that less ethanol in the mobile phase and lower temperature were favorable to this process. Moreover, two isoborneol enantiomers were obtained via a semipreparative chiral HPLC technique under optimum conditions, and further characterized by analytical HPLC, and experimental and calculated vibrational circular dichroism (VCD) spectroscopy, respectively. The solution VCD spectrum of the first-eluted component was consistent with the Density Functional Theory (DFT) calculated pattern based on the SSS configuration, indicating that this enantiomer should be (1S, 2S, 4S)-(+)-isoborneol. Briefly, these results have provided reliable information to establish a method for analysis, preparative separation, and absolute configuration of chiral compounds without typical chromophoric groups.