Conferin,potent antioxidant and anti-inflammatory isoflavone from Caragana conferta Benth

Conferin (1), a new isoflavone, has been isolated from the ethyl acetate soluble fraction of Caragana conferta Benth. along with seven known compounds, namely biochanin A (2), p-hydroxybenzoic acid (3), 3,5- dimethoxybenzoic acid (4), ursolic acid (5), erythrodiol (6), pinoresinol (7), and syringresinol (8), reported for the first time from this species. The structure of the new isoflavone was deduced on the basis of spectroscopic studies. Compounds 1 and 2 were investigated for biological activities and showed significant anti-inflammatory activity in carrageenan induced paw edema of rats. Evaluation of antioxidant activity by the radical scavenging method indicated that compound 1 is a potent antioxidant while 2 is moderately active. It was also shown that the reducing capability of compound 2 was remarkably increased in a concentration dependent manner as compared to 1. Compound 1 showed moderate inhibitory activity against the enzyme lipoxygenase, while 2 showed weak activity.     

Temperature-dependence of enantioselectivity and desymmetrization in the acetylation of 2-mono- and 2,2-di-substituted 1,3-propanediols by a novel lipase isolated from the yeast Cryptococcus spp. S-2

The effect of temperature on enantioselectivity and desymmetrization in the acetylation of 2-phenyl-1,3-propanediol (1a), 2-benzyl-1,3-propanediol (1b), 2-methyl-2-phenyl-1,3-propanediol (1c) and 2-benzyl-2-methyl-1,3-propanediol (1d) by a novel lipase (CSL) isolated from the yeast Cryptococcus spp. S-2 was studied. Desymmetrization of 1a, 1c and 1d by CSL-catalyzed acetylation was observed in the temperature range of ?20°C to 40°C, while diacetylation of 1b occurred considerably even at 0°C. The kinetic parameters of the selectivity indicated that the acetylation of 1a is an entropy controlled process whereas the reaction of 1c and 1d is mainly controlled by the enthalpy term. In the monoacetylation of the diol 1d, the preferred configuration in the enantiomeric induction by CSL was opposite to that of immobilized porcine pancreatic lipase (PPL).     

Hydroxylation of steroids by Fusarium oxysporum, Exophiala jeanselmei and Ceratocystis paradoxa

The potential of Fusarium oxysporum var. cubense UAMH 9013 to perform steroid biotransformations was reinvestigated using single phase and pulse feed conditions. The following natural steroids served as substrates: dehydroepiandrosterone (1), pregnenolone (2), testosterone (3), progesterone (4), cortisone (5), prednisone (6), estrone (7) and sarsasapogenin (8). The results showed the possible presence of C-7 and C-15 hydroxylase enzymes. This hypothesis was explored using three synthetic androstanes: androstane-3,17-dione (9), androsta-4,6-diene-3,17-dione (10) and 3α,5α-cycloandrost-6-en-17-one (11). These fermentations of non-natural steroids showed that C-7 hydroxylation was as a result of that position being allylic. The evidence also pointed towards the presence of a C-15 hydroxylase enzyme.The eleven steroids were also fed to Exophialajeanselmei var. lecanii-corni UAMH 8783. The results showed that the fungus appears to have very active 5α and 14α-hydroxylase enzymes, and is also capable of carrying out allylic oxidations.Ceratocystis paradoxa UAMH 8784 was grown in the presence of the above-mentioned steroids. The results showed that monooxygenases which effect allylic hydroxylation and Baeyer–Villiger rearrangement were active. However, redox reactions predominated.     

Periodicity of DNA in exons

Background  

The periodic pattern of DNA in exons is a known phenomenon. It was suggested that one of the initial causes of periodicity could be the universal (RNY) _n pattern (R = A or G, Y = C or U, N = any base) of ancient RNA. Two major questions were addressed in this paper. Firstly, the cause of DNA periodicity, which was investigated by comparisons between real and simulated coding sequences. Secondly, quantification of DNA periodicity was made using an evolutionary algorithm, which was not previously used for such purposes.     

Different behavior of artemisinin and tetraoxane in the oxidative degradation of phospholipid

The reaction of trioxane and tetraoxane endoperoxides with unsaturated phospholipid 1 in the presence of Fe(II) was investigated in the absence of oxygen by means of tandem ESI-MS analysis. The spectral analyses for the reaction mixtures showed that artemisinin 2 with a trioxane structure gave no peak except that for the remaining intact phospholipid 1 (m/z 758.9), indicating that there was no structural change to 1. On other hand, the reaction mixture of 1 with tetraoxanes 3 and 4 afforded a number of new peaks (m/z 620–850) that were presumably assigned to oxidative degradation products originating from phospholipid 1. Since this reaction was completely inhibited by the addition of a phenolic antioxidant, the process was considered to involve some free radical species. The newly discovered marked differences in reactivity between the trioxane and the tetraoxanes possibly reflects their different anti-malarial mechanisms, and this reactivity may contribute to the classification of a number of anti-malarial endoperoxides whose mode of action is based on phospholipid oxidation.     

Design,synthesis and anticholinesterase activity of some new α-aminobisphosphonates

Some new α-aminomethylenephosphonic acids 1–11 were synthesised and characterised by ¹H, ¹³C, ³¹P NMR, IR spectroscopy and elemental analysis. The potencies of these compounds to inhibit human erythrocyte acetylcholinesterase (hAChE, EC 3.1.1.7) were studied by a modified Ellman’s method. In addition, the log P values were computed by Hyperchem software. Here, alendronate was used as a reference inhibitor. Results showed that the IC₅₀ values ranged from 9.11 to 28.72?mM. The half maximal inhibitory concentration (IC₅₀) value decreased with an increasing number of carbon atoms of the amine group in compounds 1–5. Also, in most cases, increasing the number of carbon atoms led to enhancement of the toxicity as predicted by the log P values. Using Lineweaver-Burk and Dixon analysis, it was indicated that compounds 1–10 are mixed inhibitors while compound 11 is a coupling or uncompetitive inhibitor. The results showed that the electronic changes have ignorable effects, steric influence is important in some cases, but the lipophilicity parameter is the most significant factor in hAChE inhibition by bisphosphonates.     

Synthesis and Hybridization Properties of Oligonucleotides Containing (2 S ,3 R )-9-(2,3,4-Trihydroxybutyl)Adenine

The synthesis and properties of oligonucleotides (ONs) containing 9-(2,3,4-trihydroxybutyl)adenine, A ^C2 and A ^C3, are described. The ON containing A ^C2 involves the 3′ → 4′ and 3′ → 5′ phosphodiester linkages in the strand, whereas that containing A ^C3 possesses the 3′ → 4′ and 2′ → 5′ phosphodiester linkages. It was found that incorporation of the analogs, A ^C2 or A ^C3, into ONs significantly reduces the thermal and thermodynamic stabilities of the ON/DNA duplexes, but does not largely decrease the thermal and thermodynamic stabilities of the ON/RNA duplexes as compared with the case of the ON/DNA duplexes. It was revealed that the base recognition ability of A ^C2 is greater than that of A ^C3 in the ON/RNA duplexes.     

Desferrithiocin analogue iron chelators: iron clearing efficiency,tissue distribution,and renal toxicity

The current solution to iron-mediated damage in transfusional iron overload disorders is decorporation of excess unmanaged metal, chelation therapy. The clinical development of the tridentate chelator deferitrin (1, Table 1) was halted due to nephrotoxicity. It was then shown by replacing the 4′-(HO) of 1 with a 3,6,9-trioxadecyloxy group, the nephrotoxicity could be ameliorated. Further structure–activity relationship studies have established that the length and the position of the polyether backbone controlled: (1) the ligand’s iron clearing efficiency (ICE), (2) chelator tissue distribution, (3) biliary ferrokinetics, and (4) tissue iron reduction. The current investigation compares the ICE and tissue distribution of a series of (S)-4,5-dihydro-2-[2-hydroxy-4-(polyether)phenyl]-4-methyl-4-thiazolecarboxylic acids (Table 1, 3–5) and the (S)-4,5-dihydro-2-[2-hydroxy-3-(polyether)phenyl]-4-methyl-4-thiazolecarboxylic acids (Table 1, 8–10). The three most effective polyether analogues, in terms of performance ratio (PR), defined as mean ICE_primate/ICE_rodent, are 3 (PR 1.1), 8, (PR 1.5), and 9, now in human trials, (PR 2.2). At the onset of the clinical trial on 9, no data were available for ligand 3 or 8. This is unfortunate, as 3 has many advantages over 9, e.g., the ICE of 3 in rats is 2.5-fold greater than that of 9 and analogue 3 achieves very high levels in the liver, pancreas, and heart, the organs most affected by iron overload. Finally, the impact of 3 on the urinary excretion of kidney injury molecule-1 (Kim-1), an early diagnostic biomarker for monitoring acute kidney toxicity, has been carried out in rats; no evidence of nephrotoxicity was found. Overall, the results suggest that 3 would be a far superior clinical candidate to 9.     

Nucleosides. 140. Stereoselectivity of the Reaction of 1-(2,3-Anhydro-5-O-Benzoyl-β-D-Lyxofuranosyl) Uracil with Ammonium Azide. Isolation and Characterization of 2-Azido-Xylo-Nucleoside Derivatives

Abstract

The composition of the products of reaction of 1-(2,3-anhydro-5-O-benzoyl-β-D-lyxofuranosyl)uracil (1) with NH₄N₃ was studied by a reverse-phase HPLC system which was found to separate the 3-azido-arabino 2 and 2-azido-xylo 3 isomers that were formed. The use of a 10:1 ratio of NH ₄ N ₃ to 1 in refluxing EtOH was found to minimize ring opening at C-2 (7%). The higher stereoselectivity of ring opening produced by using a large excess of NH ₄ N ₃ was suppressed by conducting the reaction in DMF. Preventing the escape of the NH ₃ by-product only resulted in debenzoylation. The isolation of pure, crystalline 3 was achieved by reverse-phase preparative HPLC. Separation from the arabino isomer was also effected by debenzoylation and selective acetonide formation with the xylo isomer, which allowed facile isolation of the latter by normal phase chromatography. Hydrolysis of the acetonide 7 provided unprotected 2-azido-xylo nucleoside 6, which was also obtained by NaOMe treatment of 3. The mechanistic basis for the stereoselectivity of epoxide opening is discussed.     

PTEN overexpression promotes glioblastoma death through triggering mitochondrial division and inactivating the Akt pathway

Abstract

Objective: PTEN has been acknowledged as an anticancer factor in the progression of glioblastoma. Mitochondrial division has been found to be associated with cancer cell death.

Objective: The aim of our study is to explore whether PTEN attenuates the development of glioblastoma by modulating mitochondrial division.

Materials and methods: PTEN adenovirus was used to overexpress PTEN in U87 cells. Mitochondrial function was detected via western blot and immunofluorescence. Pathway blocker was used to inhibit the Akt activation.

Results: The results of our study demonstrated that PTEN overexpression reduced cell viability by increasing cell apoptosis. At the molecular level, PTEN overexpression activated mitochondrial apoptosis by mediating mitochondrial dysfunction. Furthermore, we found that Drp1-related mitochondrial division was required for PTEN-mediated mitochondrial dysfunction and cell death. Finally, we found that PTEN modulated Drp1-related mitochondrial division via the Akt pathway; inactivation of Akt induced cell death, and mitochondrial damage, similar to the results obtained via PTEN overexpression.

Conclusions: Taken together, our results clarify that the anticancer mechanism of PTEN in glioblastoma is dependent on the activation of Drp1-related mitochondrial division via Akt pathway modulation. This finding might provide new insight into the tumor-suppressive role played by PTEN in glioblastoma.     

Optimization of the 503 antigen induction strategy of Leishmania infantum chagasi expressed in Escherichia coli M15

Abstract

Leishmaniosis is a complex of diseases that can be fatal, if not given proper attention. Despite its relevance in the public health system, there is no vaccine capable of preventing the disease in humans so far and its treatment is expensive and aggressive to human health. The present study aims to optimize the induction parameters of the 503 Leishmania i. chagasi antigen expressed in recombinant Escherichia coli M15. The induction at different cell densities was evaluated in order to analyze the influence of the induction time on the yield of the protein of interest. In this segment, lactose and isopropyl-β-d-thiogalactopyranoside (IPTG) were used as inducer molecules, using various concentrations: 0.1?g/L, 1.0?g/L, and 10?g/L for lactose and 20?μM, 100?μM, 500?μM, and 1000?μM for IPTG. The results presented that the concentration of IPTG that obtained the higher antigen levels was that of 100?μM (0.087?g/L), a 10-fold lower concentration than was being previously used in this type of system and for lactose, it was 1?g/L (0.016?g/L). Thus, the induction with 100?μM allowed obtaining the antigen with a concentration 5.6 times higher than the lactose induction maximum concentration.     

Evaluation of antiproliferative activities and apoptosis induction caused by copper(II)–benzothiazolesulfonamide complexes in Jurkat T lymphocytes and Caco-2 cells

Two copper(II) complexes with a benzothiazolesulfonamide ligand, [Cu(L)₂(py)₂] (1) and [Cu(en)₂(L)₂] (2) [HL is N-2-(4-methylbenzothiazole)toluenesulfonamide, py is pyridine, en is ethylenediamine], were prepared and then characterized with the aid of X-ray crystallography and spectroscopy. Whereas the copper(II) ion in 1 presents a square-planar geometry, in 2 it has a distorted octahedral environment. In addition, although the ligand is monodentate in both complexes, it exhibits different coordination behavior in each, interacting through the benzothiazole nitrogen atom in 1 and through the sulfonamide nitrogen atom in 2. The propensity for binding of 1 and 2 to calf thymus DNA was studied by thermal denaturation, viscosimetry, and cyclic voltammetry. The ability of the complexes to cleave DNA was studied in vitro through ascorbate activation and was tested by monitoring the expression of the yEGFP gene containing the RAD54 reporter. Moreover, their antiproliferative activity was verified in two cellular models: yeast and human tumor cells in culture. While 1 was found to be the more active cleaving agent in vitro, 2 showed a higher propensity for inflicting DNA damage at the cellular level. The biological studies carried out with human tumor cells, namely, colon adenocarcinoma Caco-2 cells (HTB-37) and leukemia Jurkat T lymphocytes (TIB-152), confirmed that both compounds inhibit the growth of these cell lines, although 2 is more effective. This difference is associated with the latter compound’s greater ability to induce cell death by apoptosis. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis, characterization, and in vitro antitumor properties of gold(III) compounds with the traditional Chinese medicine (TCM) active ingredient liriodenine

Abstract  

Liriodenine, an oxoaporphine alkaloid with anticancer activity isolated from Zanthoxylum nitidum (rutaceous anticancer traditional Chinese medicine), was selected as a bioactive ligand to react with HAuCl₄ and NaAuCl₄ to afford [LH][AuCl₄] (1) and [AuCl₃L] (2), respectively (where L is liriodenine). The structures of 1 and 2 were characterized by IR spectroscopy, electrospray ionization mass spectrometry, ¹H-NMR spectroscopy, and elemental analysis. The single-crystal X-ray diffraction analysis of 1 revealed that it is an ionic compound consisting of protonated liriodenine cation [LH]⁺ and [AuCl₄]⁻ anion. The spectroscopic analysis showed that 2 is a coordination compound, in which one liriodenine coordinates to gold via its 7-N donor. In aqueous solution, 1 is relatively stable, but 2 undergoes rapid hydrolysis. The in vitro cytotoxicity towards five human tumor cell lines shows that 1 and 2 manifest roughly similar biological behavior and appreciable antiproliferative properties, with IC₅₀ values falling in the 2–16 μM range. The flow-cytometric analysis of 1 and 2 suggests that both compounds induced an S-phase arrest. Compounds 1 and 2 significantly poison topoisomerase I in vitro at low concentration (25 μM or less). DNA binding studies indicate that both 1 and 2 interact with DNA mainly via intercalation between the neighboring base pairs of the DNA double helix. Electrostatic interactions of 1 and 2 with the polyanionic DNA phosphate backbone may reinforce the intercalation because both 1 and 2 are composed of planar cationic species.     

Ginsenoside Rg3 antagonizes adriamycin-induced cardiotoxicity by improving endothelial dysfunction from oxidative stress via upregulating the Nrf2-ARE pathway through the activation of akt

BackgroundAdriamycin (ADM) is an antineoplastic agent that is effective against a wide range of cancers, but cardiac toxicity limits its clinical application. Ginsenoside Rg3 (Rg3), an anti-cancer active ingredient of Panax ginseng, was reported to have anti-oxidative, anti-apoptotic, and cardioprotective properties.PurposeThe current study aimed to investigate the possible protective effect of Rg3 against ADM-induced cardiotoxicity.Study designThe activity of Rg3 to improve endothelial dysfunction was processed both in vivo and in vitro.MethodsWe investigated the cardioprotective effect of Rg3 on ADM treated rats by echocardiography. The endothelial dysfunction was assessed using an aortic ring assay. Cardiac microvascular endothelial cells were cultured to investigate the effects of Rg3 on ADM-treated cells.ResultsResults showed that Rg3 could ameliorate the decrease in the ejection fraction and fractional shortening that was induced by ADM, and improve the left ventricular outflow. The aortic ring assay showed that Rg3 could partially recover the abnormal vascular function. In vitro studies showed that Rg3 could promote cell viability to attenuate ADM induced oxidative damage and apoptosis. This counteraction was achieved partially via activation of the Nrf2-ARE pathway through the activation of Akt.ConclusionThese findings elucidated the potential of Rg3 as a promising reagent for treating ADM-induced cardiotoxicity in clinic.     

Synthesis and Enantioselectivity of Cyclopropavir Phosphates for Cellular GMP Kinase

Enantiomeric cyclopropavir phosphates (+)-9 and (?)-9 were synthesized and investigated as substrates for GMP kinase. N²-Isobutyryl-di-O-acetylcyclopropavir (11) was converted to (+)-monoacetate 12 using hydrolysis catalyzed by porcine liver esterase. Phosphorylation via phosphite 13 gave after deacylation, phosphate (+)-9. Acid-catalyzed tetrahydropyranylation of (+)-monoacetate 12 gave, after deacylation, tetrahydropyranyl derivative 14. Phosphorylation via phosphite 15 furnished, after deprotection, enantiomeric phosphate (-)-9. Racemic diphosphate 16 was also synthesized. The phosphate (+)-9 is a relatively good substrate for GMP kinase with a K_M value of 57 μM that is similar to that of the natural substrates GMP (61 μM) and dGMP (82 μM). In contrast, the enantiomer (?)-9 is not a good substrate (K_M 1200 μM) indicating a significant enantioselectivity for the GMP kinase catalyzed reaction of monophosphate to diphosphate.     

Nest predation and semicolonial breeding in Linnets Carduelis cannabina

Capsule Nest predation in Linnets in Denmark was caused mainly by Hooded Crows Corvus corone cornix and Magpies Pica pica with no experimental evidence of antipredator aggression.

Aims To investigate the influence of nest clumping on the risk of nest predation in Linnets, a species that often breeds semi-colonially.

Methods The predation rates on clumped and randomly distributed nests were compared by the use of artificial nest experiments. Additionally, the behaviour of Linnets towards a potential nest predator was studied by presenting a mounted Magpie near the nest of breeding Linnets.

Results The artificial nest experiments showed that semi-colonial breeding was not likely to increase the risk of nest predation, and an experiment with the mounted Magpie showed that Linnets did not exhibit anti-predator aggression.

Conclusion Semi-colonial breeding, resulting in increased local nest density, did not appear to influence the risk of nest predation in Linnets. We suggest that semi-colonial breeding in Linnets is a means of pooling information on food sources.     

A new insight into the role of rat cytochrome P450 24A1 in metabolism of selective analogs of 1α,25-dihydroxyvitamin D3

We examined the metabolism of two synthetic analogs of 1α,25-dihydroxyvitamin D₃ (1), namely 1α,25-dihydroxy-16-ene-23-yne-vitamin D₃ (2) and 1α,25-dihydroxy-16-ene-23-yne-26,27-dimethyl-vitamin D₃ (4) using rat cytochrome P450 24A1 (CYP24A1) in a reconstituted system. We noted that 2 is metabolized into a single metabolite identified as C26-hydroxy-2 while 4 is metabolized into two metabolites, identified as C26-hydroxy-4 and C26a-hydroxy-4. The structural modification of adding methyl groups to the side chain of 1 as in 4 is also featured in another analog, 1α,25-dihydroxy-22,24-diene-24,26,27-trihomo-vitamin D₃ (6). In a previous study, 6 was shown to be metabolized exactly like 4, however, the enzyme responsible for its metabolism was found to be not CYP24A1. To gain a better insight into the structural determinants for substrate recognition of different analogs, we performed an in silico docking analysis using the crystal structure of rat CYP24A1 that had been solved for the substrate-free open form. Whereas analogs 2 and 4 docked similar to 1, 6 showed altered interactions for both the A-ring and side chain, despite prototypical recognition of the CD-ring. These findings hint that CYP24A1 metabolizes selectively different analogs of 1, based on their ability to generate discrete recognition cues required to close the enzyme and trigger the catalytic mechanism.     

Inhibition of Real-Time PCR in DNA Extracts from Aquifer Sediment

Variation in inhibition of real-time PCR was investigated with DNA extracts from 50 aquifer sediment core samples of 5 cm length collected through a 2.5 meter vertical profile across a landfill leachate plume. The inhibition was quantified using an internal control of the green fluorescent protein ( gfp ) gene, which was spiked into the real-time PCR reactions. The inhibition was investigated at two gfp gene concentrations: at 1.7 · 10 ⁷ gfp gene copies/g sediment (5.1 · 10 ⁴ gfp gene copies/PCR reaction) and at 1.7 · 10 ⁵ gfp gene copies/g sediment (5.1 · 10 ² gfp gene copies/PCR reaction). Despite the low TOC content of the sediment (average 0.4 mg C/g dw) the average real-time PCR response was partially inhibited, compared to a reference (pure water), at both high and low gfp concentrations. The relative amplification (reference = 1) was 0.85 ± 0.20 (high) and 0.66 ± 0.23 (low), showing significantly (P < 0.05) stronger inhibition at the lower target gene concentration. The inhibition of the real-time PCR did not show a systematic variation in the vertical profile related to plume position but variations were significant on a small scale of 5–15 cm depth intervals. One of the 50 samples failed to produce a signal with either concentration of the gfp internal control and three other samples inhibited real-time PCR at both high and low gfp concentration. These 4 samples, which were the samples with the highest inhibition, were the only DNA extracts with a visible brown colouration, indicating contents of humic-like substances. Elevated absorbance at 400 nm of these samples also indicated that humic-like substances were responsible for inhibition. However, other factors not associated with either absorbance or TOC may have contributed to the inhibition in less inhibited samples since the variation in real-time PCR response could not be sufficiently explained by absorbance or TOC. The results of this study suggest that an internal control is needed in real-time PCR reactions with DNA from environmental samples due to variation in inhibition to correctly quantify the number of target genes, especially at low target gene concentrations, when dilution of DNA extracts is not practical.     

Regio- and enantio-selective glycosylation of tetrahydroprotoberberines by <Emphasis Type="Italic">Gliocladium deliquescens</Emphasis> NRRL1086 resulting in unique alkaloidal glycosides

The microbial transformation of a series of tetrahydroprotoberberines (THPBs, 1–5) by Gliocladium deliquescens NRRL1086 was investigated. In this research, the novel glycosylation of tetrahydroberberrubine (1) was observed with fast rate and high regio- and enantio-selectivity. One pair of unique enantiomorphic alkaloidal glycosides T-1 and T-2 was isolated and their structures were elucidated unambiguously by HR-MS, CD, 1D and 2D NMR spectrum. It is interesting that different amounts of glucose in the potato broth medium could influence the ratio of T-1 and T-2; in the 1.5% glucose medium, the ratio was about 15:1 and the yield of the S-form product T-1 may reach the theoretical maximum yield of about 50% which could provide one practical method to prepare the enantiomerically pure product and one alternative resolution method of tetrahydroberberrubine. The preliminary enzymatic research by using sodium dodecyl sulfate (SDS) and imidazole as glycosyltransferase and glycosidase inhibitors revealed that glycosyltransferase may contribute to glycosylation process. This is the first successful approach to glycosylation of tetrahydroprotoberberines.     

Synthesis and Field Evaluation of Methyl-branched Ketones,Sex Pheromone Components Produced by Lithosiinae Female Moths in the Family of Arctiidae

Female moths of Lyclene dharma dharma (Arctiidae, Lithosiinae) produce a novel sex pheromone composed of three methyl-branched ketones (I–III) in a ratio of 2:1:1. In order to confirm the structure of III (6,14-dimethyl-2-octadecanone), a mixture of its four stereoisomers was synthesized via chain elongation by two Wittig reactions, starting from 1,7-hexanediol. GC-MS data of the synthetic III were satisfactorily coincident with those of the natural component. In addition to the racemic mixtures of I (6-methyl-2-octadecanone) and II (14-methyl-2-octadecanone), previously synthesized, the activity of III was evaluated in the Iriomote Islands, and effective male attraction was observed for the 2:1:1 mixture of I–III. This result indicates that the females do not produce only one stereoisomer for each component or that the response of the males is not disturbed by the other stereoisomers of natural isomers produced by the females. The field test also revealed that the two-component lure of I and II captured as many males as the mixture of I–III, while lures baited with two components in other combinations and with only one component scarcely exhibited any male attraction ability.