Aromaticity of graphene nanoflakes in a new way: fragment analysis by combination of the nucleus-independent chemical shifts and the anisotropy of current induced density

A graphene nanoflake (GNF) is a polycyclic aromatic hydrocarbon (PAH) with a huge two-dimensional π-conjugated carbon material in which a central benzene ring is surrounded by identical benzene-type rings through infinite alternant method. In this paper, we explore the structure-aromaticity relationship of the GNFs and the GNFs with hollow sites (GNFHs) by combining the nucleus-independent chemical shifts (NICS) with the anisotropy of the current induced density (ACID). Firstly, the benzene is a typical aromatic molecule (NICS = ?9.671 ppm), GNFs 1-6 is darned with benzene and the corresponding GNFHs 1′-6′. Secondly, the NICS values of GNFs 1-6 alternately vary: ?1.214 (1) > ?13.847 (2) < ?2.662 (3) > ?14.530 (4) < ?3.932 (5) > ?13.978 (6) ppm, the GNFs (2, 4, 6) with even fragments of annulene have larger aromaticity than that of GNFs (1, 3, 5) with odd fragments of annulene. Significantly, the NICS values of GNFs 1-6 can also be fragment analyzed by the NICS values and ACID of benzene and corresponding GNFHs 1′-6′. The NICS values for GNFs (2, 4, 6) can be roughly estimated by the NICS value of benzene minus the NICS value of the GNFHs (2′, 4′, 6′), respectively. The NICS values for GNFs (1, 3, 5) can be roughly estimated by the NICS value of the GNFHs (1′, 3′, 5′) minus the NICS value of benzene, respectively. We hope that the present work can provide a simple and reliable method for the rational design of the GNF with aromaticity, which may be used to understand the origin of the graphene nanoflake aromatic properties.     

Tyrosinase and catechol oxidase activity of copper(I) complexes supported by imidazole-based ligands: structure–reactivity correlations

Four new imidazole-based ligands, 4-((1H-imidazol-4-yl)methyl)-2-phenyl-4,5-dihydrooxyzole (L _OL 1), 4-((1H-imidazol-4-yl)methyl)-2-(tert-butyl)-4,5-dihydrooxyzole (L _OL 2), 4-((1H-imidazol-4-yl)methyl)-2-methyl-4,5-dihydrooxyzole (L _OL 3), and N-(2,2-dimethylpropylidene)-2-(1-trityl-1H-imidazol-4-yl-)ethyl amine (L _imz 1), have been synthesized. The corresponding copper(I) complexes [Cu(I)(L _OL 1)(CH₃CN)]PF₆ (CuL _OL 1), [Cu(I)(L _OL 2)(CH₃CN)]PF₆ (CuL _OL 2), [Cu(I)(L _OL 3)(CH₃CN)]PF₆ (CuL _OL 3), [Cu(I)(L _imz 1)(CH₃CN)₂]PF₆ (CuL _imz 1) as well as the Cu(I) complex derived from the known ligand bis(1-methylimidazol-2-yl)methane (BIMZ), [Cu(I)(BIMZ)(CH₃CN)]PF₆ (CuBIMZ), are screened as catalysts for the oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC-H₂) to 3,5-di-tert-butylquinone (3,5-DTBQ). The primary reaction product of these oxidations is 3,5-di-tert-butylsemiquinone (3,5-DTBSQ) which slowly converts to 3,5-DTBQ. Saturation kinetic studies reveal a trend of catalytic activity in the order CuL _OL 3 ≈ CuL _OL 1 > CuBIMZ > CuL _OL 2 > CuL _imz 1. Additionally, the catalytic activity of the copper(I) complexes towards the oxygenation of monophenols is investigated. As substrates 2,4-di-tert-butylphenol (2,4-DTBP-H), 3-tert-butylphenol (3-TBP-H), 4-methoxyphenol (4-MeOP-H), N-acetyl-l-tyrosine ethyl ester monohydrate (NATEE) and 8-hydroxyquinoline are employed. The oxygenation products are identified and characterized with the help of UV/Vis and NMR spectroscopy, mass spectrometry, and fluorescence measurements. Whereas the copper complexes with ligands containing combinations of imidazole and imine functions or two imidazole units (CuL _imz 1 and CuBIMZ) are found to exhibit catalytic tyrosinase activity, the systems with ligands containing oxazoline just mediate a stoichiometric conversion. Correlations between the structures of the complexes and their reactivities are discussed.     

Differential alkaloid profile in <Emphasis Type="Italic">Uncaria tomentosa</Emphasis> micropropagated plantlets and root cultures

The alkaloids of Uncaria tomentosa micropropagated plantlets and root cultures were isolated and identified by NMR and mass spectrometry. Plantlets yielded pteropodine (1), isopteropodine (2), mitraphylline (3), isomitraphylline (4), uncarine F (5), speciophylline (6), rhynchophylline (7) and isorhynchophylline (8). In plantlets growing under continuous light, tetracyclic alkaloids 7 and 8 decreased from 20 ± 1.8 at 2 months to 2.2 ± 0.33 mg/g dry wt at 6 months, while the pentacyclic alkaloids 1–4 increased from 7.7 ± 1.4 to 15 ± 0.05 mg/g dry wt, supporting their biogenetic conversion. Micropropagated plantlets produced four times more alkaloids (27.6 ± 3.1 mg/g dry wt) than greenhouse plants. Plantlet roots yielded 3, 4, 8 and the glucoindole alkaloids 3α-dihydrocadambine (9) and dolichantoside (10), the last one not previously found in Uncaria.     

Dietary Supplementation of Selenium-Enriched Probiotics Enhances Meat Quality of Broiler Chickens (<Emphasis Type="Italic">Gallus gallus domesticus</Emphasis>) Raised Under High Ambient Temperature

We investigated the effects of selenium-enriched probiotics (SP) on broiler meat quality under high ambient temperature and explore their underlying mechanisms. A total of 200 1-day-old male broiler chicks (Ross 308) were randomly allotted to four treatment groups, each with five replicates, in groups of ten birds. These birds were fed a corn-soybean basal diet (C), a basal diet plus probiotics supplementation (P), a basal diet plus Se supplementation in the form of sodium selenite (SS, 0.30 mg Se/kg), and a basal diet with the addition of selenium-enriched probiotics (SP, 0.30 mg Se/kg). The experiment lasted for 42 days. The birds were sacrificed by cervical dislocation, and the breast muscles were removed for further process. Our results showed that SP diet significantly increased (p < 0.05) the physical (pH, colors, water holding capacity, drip loss, shear force) and sensory characteristics of breast meat. All P, SS, and SP supplementation enhanced the antioxidant system by increasing (p < 0.05) the Se concentrations, glutathione (GSH) levels, activities of glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) whereas decreasing (p < 0.05) malondialdehyde (MDA) levels, with SP being higher than P and SS. Moreover, SP diet significantly upregulated (p < 0.05) the mRNA levels of glutathione peroxidase genes (GPx1, GPx4) while it downregulated heat stress biomarkers such as heat shock protein (HSP) 70 as compared to C, P, and SS diets. In conclusion, our findings suggest that SP may function as beneficial nutritive supplement that is capable of improving meat quality during the summer season.     

Bioactive compounds of <Emphasis Type="Italic">Aspergillus terreus</Emphasis>—F7, an endophytic fungus from <Emphasis Type="Italic">Hyptis suaveolens</Emphasis> (L.) Poit

The compounds terrein (1), butyrolactone I (2), and butyrolactone V (3) were isolated from the ethyl acetate extract (EtOAc) of the endophytic fungus Aspergillus terreus—F7 obtained from Hyptis suaveolens (L.) Poit. The extract and the compounds presented schistosomicidal activity against Schistosoma mansoni; at 100 µg/mL for EtOAc extract, 1297.3 µM for compound 1, 235.6 µM for compound 2, and 454.1 µM for compound 3, they killed 100% of the parasites after 72 h of treatment. Compounds 1, 2, and 3 exerted moderate leishmanicidal activity against Leishmania amazonensis (IC₅₀ ranged from 23.7 to 78.6 µM). At 235.6 and 227.0 µM, compounds 2 and 3, respectively, scavenged 95.92 and 95.12% of the DPPH radical (2,2-diphenyl-1-picryl-hydrazyl), respectively. Regarding the cytotoxicity against the breast tumor cell lines MDA-MB-231 and MCF-7, compound 2 gave IC₅₀ of 34.4 and 17.4 µM, respectively, while compound 3 afforded IC₅₀ of 22.2 and 31.9 µM, respectively. At 117.6 µM, compound 2 inhibited the growth of and killed the pathogen Escherichia coli (ATCC 25922). Compounds 1, 2, and 3 displayed low toxicity against the normal line of human lung fibroblasts (GM07492A cells), with IC₅₀ of 15.3?×?10³, 3.4?×?10³, and 5.8?×?10³ µM, respectively. This is the first report on (i) the in vitro schistosomicidal and leishmanicidal activities of the EtOAc extract of A. terreus—F7 and compounds 1, 2, and 3; and (ii) the antitumor activity of compounds 2 and 3 against MDA-MB-231 and MCF-7 cells.     

Synthesis and evaluation of copper(II) complexes with isoniazid-derived hydrazones as anticancer and antitubercular agents

In this study, the N,N,O metal chelator 2-pyridinecarboxaldehydeisonicotinoyl hydrazone (HPCIH, 1) and its derivatives 2-acetylpyridine-(HAPIH 2), 2-pyridineformamide-(HPAmIH, 3) and pyrazineformamide-(HPzAmIH, 4) were employed in the synthesis of four copper(II) complexes, [Cu(HPCIH)Cl₂]·0.4H₂O (5), [Cu(HAPIH)Cl₂]·1.25H₂O (6), [Cu(HPAmIH)Cl₂]·H₂O (7) and [Cu(HPzAmIH)Cl₂]·1.25H₂O (8). The compounds were assayed for their action toward Mycobacterium tuberculosis H37Rv ATCC 27294 strain and the human tumor cell lines OVCAR-8 (ovarian cancer), SF-295 (glioblastoma multiforme) and HCT-116 (colon adenocarcinoma). All copper(II) complexes were more effective in reducing growth of HCT-116 and SF-295 cells than the respective free hydrazones at 5 µg/mL, whereas only complex 7 was more cytotoxic toward OVCAR-8 lines than its ligand HPAmIH. 6 proved to be cytotoxic at submicromolar doses, whose IC₅₀ values (0.39–0.86 µM) are similar to those ones found for doxorubicin (0.23–0.43 µM). Complexes 5 and 6 displayed high activity against M. tuberculosis (MIC = 0.85 and 1.58 µM, respectively), as compared with isoniazid (MIC = 2.27 µM), which suggests the compounds are attractive candidates as antitubercular drugs.     

Design,synthesis, and characterization of 2,2-bis(2,4-dinitrophenyl)-2-(phosphonatomethylamino)acetate as a herbicidal and biological active agent

The present study was designed to synthesize the bioactive molecule 2,2-bis(2,4-dinitrophenyl)-2-(phosphonatomethylamino)acetate (1), having excellent applications in the field of plant protection as a herbicide. Structure of newly synthesized molecule 1 was confirmed by using the elemental analysis, mass spectrometric, NMR, UV-visible, and FTIR spectroscopic techniques. To obtain better structural insights of molecule 1, 3D molecular modeling was performed using the GAMESS programme. Microbial activities of 1 were checked against the pathogenic strains Aspergillus fumigatus (NCIM 902) and Salmonella typhimurium (NCIM 2501). Molecule 1 has shown excellent activities against fungal strain A. fumigates (35 μg/l) and bacterial strain S. typhimurium (25 μg/l). To check the medicinal significance of molecule 1, interactions with bovine serum albumin (BSA) protein were checked. The calculated value of binding constant of molecule 1–BSA complex was 1.4 × 10⁶ M^?1, which were similar to most effective drugs like salicylic acid. More significantly, as compared to herbicide glyphosate, molecule 1 has exhibited excellent herbicidal activities, in pre- and post-experiments on three weeds; barnyard grass (Echinochloa Crus), red spranglitop (Leptochloa filiformis), and yellow nuts (Cyperus Esculenfus). Further, effects of molecule 1 on plant growth-promoting rhizobacterial (PGPR) strains were checked. More interestingly, as compared to glyphosate, molecule 1 has shown least adverse effects on soil PGPR strains including the Rhizobium leguminosarum (NCIM 2749), Pseudomonas fluorescens (NCIM 5096), and Pseudomonas putida (NCIM 2847).     

Isolation and Antibiotic Screening of Fungi from a Hydrothermal Vent Site and Characterization of Secondary Metabolites from a <Emphasis Type="Italic">Penicillium</Emphasis> Isolate

Five new compounds were isolated from Penicillium sp. Y-5-2 including an austin derivative 4, four isocoumarins 9, 11, 12, and 13, together with two known isocoumarins 8 and 10, and six known austin derivatives 1, 2, 3, 5, 6, and 7 and one phenol 14. Their structures and relative configurations were established by spectroscopic means. The absolute configurations of 4, 11, and 13 were defined mainly by comparison of quantum chemical TDDFT calculated and experimental ECD spectra. The cyclization of the pentan-2-ol pendant at C-3 in compound 13 allowed the assignment of a new 2,3,4,4a,6,10b-hexahydro-1H-benzo[c]chromene isocoumarin skeleton. New compounds 9, 11, and 13 revealed inhibitory activities against E. coli at MIC values around 32 μg/mL. The known compound 14 showed potent antibiotic activity against Staphylococcus aureus and Bacillus subtilis with MIC values 8 and 2 μg/mL, respectively, with no cytotoxicity when tested in vitro. A rapid and efficient technique for selecting antibiotic fungal strain among eight marine-derived fungi was also described.     

Preparation,Structure, and Potent Antifouling Activity of Sclerotioramine Derivatives

A series of 30 sclerotioramine derivatives (2–31) of the natural compound, (+)-sclerotiorin (1), has been successfully semi-synthesized by a one-step reaction with high yields (up to 80%). The structures of these new derivatives were established by extensive spectroscopic methods and single-crystal X-ray diffraction analysis for 3, 6, and 10. (+)-Sclerotiorin (1) and its semisynthetic derivatives (2–31) were evaluated for their antifouling activity. Most of them except 6, 7, 8, 12, and 28 showed potent antifouling activity against the larval settlement of the barnacle Balanus amphitrite. More interestingly, most of the aromatic amino-derivatives (13–17, 19–21, 23, 25–27, and 29–31) showed strong antifouling activity; however, only two aliphatic amino-derivatives (5 and 10) had the activity.     

A mechanistic investigation on the formation and rearrangement of silaspiropentane: A theoretical study

The formation of silaspiropentane from addition of singlet silacyclopropylidene 1 and silacyclopropylidenoid 8 to ethylene has been investigated separately at the B3LYP, X3LYP, WB97XD, and M05–2X theories using the 6–31+G(d,p) basis set. The silacycloproylidenoid addition follows a stepwise route. In contrast, a concerted mechanism occurs for silacyclopropylidene addition. Moreover, the intramolecular rearrangements of silaspiropentane 9 to methylenesilacyclobutane 11 and 2-silaallene?+?ethylene 12 have been studied extensively. The required energy barrier for the isomerization of 9 to 10 was determined to be 44.0 kcal mol^?1 at the B3LYP/6–31+G(d,p) level. After formation of 10, the rearrangement to methylenesilacyclobutane 12 is highly exergonic by ?15.9 kcal mol^?1, which makes this reaction promising. However, the conversion of 9 to 11 is calculated to be quite endergonic, by 26.5 kcal mol^?1.     

Significant increase of oleic acid level in the wild species <Emphasis Type="Italic">Lepidium campestre</Emphasis> through direct gene silencing

Key message

Simultaneous RNAi silencing of the FAD2 and FAE1 genes in the wild species Lepidium campestre improved the oil quality with 80 % oleic acid content compared to 11 % in wildtype.

Abstract

Field cress (Lepidium campestre) is a wild biennial species within the Brassicaceae family with desirable agronomic traits, thus being a good candidate for domestication into a new oilseed and catch crop. However, it has agronomic traits that need to be improved before it can become an economically viable species. One of such traits is the seed oil composition, which is not desirable either for food use or for industrial applications. In this study, we have, through metabolic engineering, altered the seed oil composition in field cress into a premium oil for food processing, industrial, or chemical industrial applications. Through seed-specific RNAi silencing of the field cress fatty acid desaturase 2 (FAD2) and fatty acid elongase 1 (FAE1) genes, we have obtained transgenic lines with an oleic acid content increased from 11 % in the wildtype to over 80 %. Moreover, the oxidatively unstable linolenic acid was decreased from 40.4 to 2.6 %, and the unhealthy erucic acid was reduced from 20.3 to 0.1 %. The high oleic acid trait has been kept stable for three generations. This shows the possibility to use field cress as a platform for genetic engineering of oil compositions tailor-made for its end uses.

     

An NADPH-dependent <Emphasis Type="Italic">Lactobacillus composti</Emphasis> short-chain dehydrogenase/reductase: characterization and application to (<Emphasis Type="Italic">R</Emphasis>)-1-phenylethanol synthesis

A new anti-Prelog short-chain dehydrogenase/reductase (SDR) encoding gene lcsdr was cloned from Lactobacillus composti DSM 18527, and heterologously expressed in Escherichia coli. LcSDR is nicotinamide adenine dinucleotide phosphate (NADPH)-dependent and has a molecular weight of approximately 30 kDa. The optimal pH and temperature were 6.5 and 30?°C, respectively. The maximal reaction rate V_max was 133.9 U mg^?1; the Michaelis–Menten constant K _m of LcSDR were 0.345 mM for acetophenone (1a), and 0.085 mM for NADPH. Through introducing an EsGDH-catalyzed NADPH regeneration system, a biocatalytic process for (R)-1-phenylethanol ((R)-1b) was developed with outstanding time–space yield. Under the optimized conditions, 50 g l^?1 1a was converted to (R)-1b in 2 h with a yield of 93.8%, enantiomeric excess of product (e.e._p) above 99% and space–time yield of 562.8 g l^?1 d^?1.     

Design and synthesis of an indol derivative as antibacterial agent against <Emphasis Type="Italic">Staphylococcus aureus</Emphasis>

Several indole derivatives with antibacterial activity have been prepared using different protocols; however, some require special reagents and conditions. The aim of this study involved the synthesis of some indole derivatives using estrone and OTBS-estrone as chemical tools. The synthesis of the indole derivatives involves reactions such as follows: (1) synthesis of two indol derivatives (4 or 5) by reaction of estrone or OTBS-estrone with phenylhydrazine in medium acid; (2) reaction of 4 or 5 with 6-cloro-1-hexyne in medium basic to form two hexynyl-indol (7 or 8); (3) preparation of indol-propargylic alcohol derivatives (10 or 11) by reaction of benzaldehyde with 7 or 8 in medium basic; (4) synthesis of indol-aldehydes (12 or 13) via oxidation of 10 or 11 with DMSO; (5) synthesis of indeno-indol-carbaldehyde (15 or 16) via alkynylation/cyclization of 12 or 13 with hexyne in presence of copper(II); (6) preparation indeno-indol-carbaldehyde complex (19 or 20) via alkynylation/cyclization of 12 or 13 with 1-(hex-5-yn-1-yl)-2-phenyl-1H-imidazole. The antibacterial effect exerted by the indol-steroid derivatives against Streptococcus pneumoniae and Staphylococcus aureus bacteria was evaluated using dilution method and the minimum inhibitory concentration (MIC). The results showed that only the compound 19 inhibit the growth bacterial of S. aureus. In conclusion, these data indicate that antibacterial activity of 19 can be due mainly to functional groups involved in the chemical structure in comparison with the compounds studied.     

Synthesis,Antimicrobial and Antioxidant Activity of Pyrazole Based Sulfonamide Derivatives

A series of new sulfonamides have been synthesized from Ampyrone with different benzene sulfonyl chlorides to yield the N-1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl) benzenesulfonamides (4a–e). All synthesized compounds were characterized on the basis of FTIR, ¹H NMR, and ¹³C NMR, and also by the aid of mass spectral data. Further, all synthesized compounds have studied for their in vitro antimicrobial activities against selected bacterial as well as fungal strains by the agar well diffusion method. Free radical scavenging activity has been investigated by using DPPH method. Among all the synthesized compounds, 4b, 4d, and 4e exhibited significant antimicrobial and antioxidant activities.     

Localization of magnetized electrons in current filaments as a fundamental cause of Coulomb explosion

Mechanisms for generating current filaments in a dense plasma under the action of focused laser pulses and in a Z-pinch configuration are discussed. The main properties of current filaments with a zero and nonzero electron vorticity Ω _e =B?(c/e)?×p _e that originate at magnetic fields in the range 4πn _e m _e c²?B²?4πn _i m _i c² are investigated under the conditions of Coulomb explosion at currents below the ion Alfvén current. A study is made of the equilibrium configurations of nonquasineutral current filaments in a purely longitudinal (B_z) and a purely azimuthal (B_θ) magnetic field and also in a more general case of a helical magnetic field, having two components, under conditions such that the charge separation occurs on a spatial scale on the order of the magnetic Debye radius r_B ? |B|/(4πen_e. It is shown that strong electric fields generated in the current filaments are comparable in magnitude to the atomic field and are capable of accelerating ions to energies of several tens of megaelectronvolts. The ion dynamics in strong electric fields of the filaments is calculated numerically and is shown to lead to the formation of collisionless shock waves on time scales on the order of several inverse ion plasma frequencies ω _pi ^?1 . The possible formation of current filaments on different spatiotemporal scales is considered.     

Mangrove root: adaptations and ecological importance

Key message

This review gives a comprehensive overview of adaptations of mangrove root system to the adverse environmental conditions and summarizes the ecological importance of mangrove root to the ecosystem.

Abstract

In plants, the first line of defense against abiotic stress is in their roots. If the soil surrounding the plant root is healthy and biologically diverse, the plant will have a higher chance to survive in stressful conditions. Different plant species have unique adaptations when exposed to a variety of abiotic stress conditions. None of the responses are identical, even though plants have become adapted to the exact same environment. Mangrove plants have developed complex morphological, anatomical, physiological, and molecular adaptations allowing survival and success in their high-stress habitat. This review briefly depicts adaptive strategies of mangrove roots with respect to anatomy, physiology, biochemistry and also the major advances recently made at the genetic and genomic levels. Results drawn from the different studies on mangrove roots have further indicated that specific patterns of gene expression might contribute to adaptive evolution of mangroves under high salinity. We also review crucial ecological contributions provided by mangrove root communities to the ecosystem including marine fauna.

     

Allometric biomass,nutrient and carbon stock models for <Emphasis Type="Italic">Kandelia candel</Emphasis> of the Sundarbans,Bangladesh

Key message

Present study recommends DBH as independent variable of the derived allometric models and Biomass = a + b DBH ² has been selected for total above-ground biomass, nutrients and carbon stock.

Abstract

Kandelia candel (L.) Druce is a shrub to small tree of the Sundarbans mangrove forest of Bangladesh. The aim of the study was to derive the allometric models for estimating above-ground biomass, nutrient and carbon stock in K. candel. A total of eight linear models with 64 regression equations were tested to derive the allometric models for biomass of each part of plant; and nutrients and carbon stock in total above-ground biomass. The best fitted allometric models were selected by considering the values of R ², CV, R _mse, MS_error, S _a, S _b, F value, AICc and Furnival Index. The selected allometric models were Biomass = 0.014 DBH² + 0.03; √Biomass = 0.29 DBH ? 0.21; √Biomass = 0.66 √DBH ? 0.57; √Biomass = 1.19 √DBH ? 1.02; Biomass = 0.21 DBH² + 0.12 for leaves, branches, bark, stem without bark and total above-ground biomass, respectively. The selected allometric models for Nitrogen, Phosphorous, Potassium and Carbon stock in total above-ground biomass were N = 0.39 DBH² + 0.49, P = 0.77 DBH² + 0.14, K = 0.87 DBH² + 0.07 and C = 0.09 DBH² + 0.05, respectively. The derived allometric models have included DBH as a single independent variable, which may give quick and accurate estimation of the above-ground biomass, nutrient and carbon stock in this species. This information may also contribute to a broader study of nutrient cycling, nutrient budgeting and carbon sequestration of the studied forest.

     

Organic Solvent-Tolerant Marine Microorganisms as Catalysts for Kinetic Resolution of Cyclic β-Hydroxy Ketones

Chiral cyclic β-hydroxy ketones represent key motifs in the production of natural products of biological interest. Although the molecules are structurally simple, they require cumbersome synthetic steps to get access to them and their synthesis remains a challenge in organic chemistry. In this report, we describe a straightforward approach to enantiomerically enriched (R)- and (S)-3-hydroxycyclopentanone 2a, (R)- and (S)-3-hydroxycyclohexanone 2b, and (R)- and (S)-3-hydroxycycloheptanone 2c involving a transesterification resolution of the racemates using whole cells of marine microorganisms as catalysts and vinyl acetate the acyl donor and solvent. Twenty-six strains from a wide collection of isolates from marine sediments were screened, and seven strains were found to markedly catalyze the resolution in an asymmetric fashion. Using the strain Serratia sp., (R)-2a was isolated in 27% yield with 92% ee and (S)-2a in 65% yield with 43% ee, corresponding to an E-value of 37; (R)-2b was isolated in 25% yield with 91% ee and (S)-2b in 67% yield with 39% ee, corresponding to an E-value of 40; and (R)-2c was isolated in 30% yield with 96% ee and (S)-2c in 63% yield with 63% ee, corresponding to an E-value of 75.