Stereoconservative and stereoselective syntheses of rare and non-naturalα-amino acids from (S)-aspartic acid and (S)-malic acid

Summary A new strategy for stereoconservative and stereoselective syntheses of several types of amino acids starting from-functional carboxylic acids employing hexafluoroacetone as protecting and activating reagent is described. Outstanding features of this new method are the mild reaction conditions and the high yields for introduction and cleavage of the protective group allowing sensitive functional groups in the side chain to survive. Furthermore, the new concept results in saving of synthetic steps.     

In Vitro Characterization of Echinomycin Biosynthesis: Formation and Hydroxylation of L-Tryptophanyl-S-Enzyme and Oxidation of (2S,3S) β-Hydroxytryptophan

Quinoxaline-2-carboxylic acid (QXC) and 3-hydroxyquinaldic acid (HQA) feature in quinomycin family and confer anticancer activity. In light of the significant potency against cancer, the biosynthetic gene clusters have been reported from many different Streptomyces strains, and the biosynthetic pathway were proposed mainly based on the in vivo feeding experiment with isotope labeled putative intermediates. Herein we report another gene cluster from Streptomyces griseovariabilis subsp. bandungensis subsp. nov responsible for the biosynthesis of echinomycin (a member of quinomycin family, also named quinomycin A) and presented in vitro evidence to corroborate the previous hypothesis on QXC biosynthesis, showing that only with the assistance of a MbtH-like protein Qui5, did the didomain NRPS protein (Qui18) perform the loading of a L-tryptophan onto its own PCP domain. Particularly, it was found that Qui5 and Qui18 subunits form a functional tetramer through size exclusion chromatography. The subsequent hydroxylation on β-carbon of the loaded L-tryptophan proved in vitro to be completed by cytochrome P450-dependent hydroxylase Qui15. Importantly, only the Qui18 loaded L-tryptophan can be hydroxylated by Qui15 and the enzyme was inactive on free L-tryptophan. Additionally, the chemically synthesized (2S,3S) β-hydroxytryptophan was detected to be converted by the tryptophan 2,3-dioxygenase Qui17 through LC-MS, which enriched our previous knowledge that tryptophan 2,3-dioxygenase nearly exclusively acted on L-tryptophan and 6-fluoro-tryptophan.     

Synthesis and cytokinin activity of (R)-(+)- and (S)-(−)-dihydrozeatins and their ribosides

(R)-(+)- and (S)-(?)-dihydrozeatins [(R)-(+)- and (S)-(?)-6-(4-hydroxy-3-methylbutylamino)purines, 1a and 1b] and their ribosides {(?)-6-[(R)-4-hydroxy-3-methylbutylamino]- and (?)-6-[(S)-4-hydroxy-3-methyl-butylamino]-9-β-D-ribofuranosylpurines, 3a and 3b} were synthesized and tested for their cytokinin activity by four bioassay systems, the growth of tobacco callus, the seed germination of lettuce, the fr. wt increase of excised radish cotyledons and the retardation of chlorophyll degradation in radish cotyledons. In tobacco callus bioassay, 1a was more active than 1b. The ribosides 3a and 3b were not less active than their corresponding aglycones 1a and 1b. In other bioassays used the activity followed the order: 1a >3a >1b >3b. In tobacco callus bioassay and lettuce seed germination, trans-zeatin [6-(4-hydroxy-3-methylbut-trans-2-enylamino)purine] showed stronger cytokinin activity than 1a.     

Karyotype and Chromosomal Location of 18S–28S and 5S Ribosomal DNA in the Scallops Pecten maximus and Mimachlamys varia (Bivalvia: Pectinidae)

This work describes the karyotype and chromosomal location of the ribosomal DNA (rDNA) of Pecten maximus and Mimachlamys varia, two commercial scallop species from Europe. According to the chromosome centromeric index values found, the karyotype of P. maximus is composed of 1 metacentric, 2 metacentric–submetacentric, 1 telocentric–subtelocentric and 15 telocentric pairs, and that of M. varia of 4 metacentric, 2 subtelocentric–submetacentric, 9 subtelocentric, 3 subtelocentric–telocentric and 1 telocentric–subtelocentric pairs. In P. maximus, 18S-28S rDNA was located by FISH on a metacentric–submetacentric pair, and in M. varia on a subtelocentric–submetacentric pair using both silver staining and FISH. PCR amplification of the 5S rDNA unit yielded a single product of about 460 bp (P. maximus) and 450 bp (M. varia), that used as probe revealed a 5S rDNA site on a telocentric pair in P. maximus and a subtelocentric pair in M. varia. Two-color FISH or sequential silver staining of 5S rDNA-FISH-metaphases corroborated that the two gene families are located on different chromosomes in both species. A comparative analysis of the data allowed the inference of karyotypic relationships within scallops.     

Macroalgal species diversity and biomass of subtidal communities of São Miguel (Azores)

The benthic algal communities of two subtidal sites, located on opposite coasts of S?o Miguel Island (S?o Roque in the south and S?o Vicente on the north coast), were studied over a 2 year period (September 1993–September 1995). At both sites the sublittoral region was surveyed from low-tide level down to a depth of 15 m. Qualitative and quantitative changes are described. A depth-related gradient in species diversity and biomass was found at both localities. In general, red algae such as corallines and Pterocladiella capillacea predominated in the shallow sublittoral (5 m) while brown algae such as Zonaria and Stypocaulon were more abundant at 15 m. Multivariate analyses emphasized the existence at each study site of two communities (5 and 15 m depth), separated by a large transition zone. The 15 m community on the south coast site showed the largest number of species (52), whereas the lowest diversity (30 species) also occurred at this site in the 5 m community. A clear seasonal pattern of biomass change could be discerned only at S?o Vicente where the highest biomass was recorded in spring/summer. No major inter-annual variations could be detected, indicating relatively stable communities at least on a short-term basis. Received in revised form: 28 March 2001 Electronic Publication     

Complete cloning of the chloroplast genome of safflower in λ EMBL3 and mapping of 23S and 16S rRNA genes

Summary A recombinant DNA library was constructed from partial BamHI or MboI digests of safflower (Carthamus tinctorius L.) chloroplast DNA, in the BamHI site of EMBL3. Seventeen recombinants, selected by chromosome walking, were found to contain overlapping fragments of the entire chloroplast genome. These clones were mapped using single and double digests of BamHI, EcoRI and HindIII. cDNAs synthesized from isolated 16S and 23S chloroplast rRNAs were used to map the ribosomal RNA genes relative to physical maps of the above restriction enzymes. The mapped positions of the rRNA genes for the safflower chloroplast DNA are in good agreement with previously published data for tobacco, spinach and several other higher plants.     

Positions of the cytoplasmic end of BK α S0 helix relative to S1–S6 and of β1 TM1 and TM2 relative to S0–S6

The large-conductance, voltage- and Ca²⁺-gated K⁺ (BK) channel consists of four α subunits, which form a voltage- and Ca²⁺-gated channel, and up to four modulatory β subunits. The β1 subunit is expressed in smooth muscle, where it slows BK channel kinetics and shifts the conductance–voltage (G-V) curve to the left at [Ca²⁺] > 2 µM. In addition to the six transmembrane (TM) helices, S1–S6, conserved in all voltage-dependent K⁺ channels, BK α has a unique seventh TM helix, S0, which may contribute to the unusual rightward shift in the G-V curve of BK α in the absence of β1 and to a leftward shift in its presence. Such a role is supported by the close proximity of S0 to S3 and S4 in the voltage-sensing domain. Furthermore, on the extracellular side of the membrane, one of the two TM helices of β1, TM2, is adjacent to S0. We have now analyzed induced disulfide bond formation between substituted Cys residues on the cytoplasmic side of the membrane. There, in contrast, S0 is closest to the S2–S3 loop, from which position it is displaced on the addition of β1. The cytoplasmic ends of β1 TM1 and TM2 are adjacent and are located between the S2–S3 loop of one α subunit and S1 of a neighboring α subunit and are not adjacent to S0; i.e., S0 and TM2 have different trajectories through the membrane. In the absence of β1, 70% of disulfide bonding of W43C (S0) and L175C (S2–S3) has no effect on V₅₀ for activation, implying that the cytoplasmic end of S0 and the S2–S3 loop move in concert, if at all, during activation. Otherwise, linking them together in one state would obstruct the transition to the other state, which would certainly change V₅₀.     

Distribution of 5S and 18S–28S rDNA loci in a tetraploid cotton (Gossypium hirsutum L.) and its putative diploid ancestors

The most widely cultivated species of cotton,Gossypium hirsutum, is a disomic tetraploid (2n=4x=52). It has been proposed previously that extant A- and D-genome species are most closely related to the diploid progenitors of the tetraploid. We used fluorescent in situ hybridization (FISH) to determine the distribution of 5S and 18S-28S rDNA loci in the A-genome speciesG. herbaceum andG. arboreum, the D-genome speciesG. raimondii andG. thurberi, and the AD tetraploidG. hirsutum. High signal-to-noise, single-label FISH was used to enumerate rDNA loci, and simultaneous, dual-label FISH was used to determine the syntenic relationships of 5S rDNA loci relative to 18S–28S rDNA loci. These techniques provided greater sensitivity than our previous methods and permitted detection of six newG. hirsutum 18S–28S rDNA loci, bringing the total number of observed loci to 11. Differences in the intensity of the hybrizization signal at these loci allowed us to designate them as major, intermediate, or minor 18–28S loci. Using genomic painting with labeled A-genome DNA, five 18S–28S loci were localized to theG. hirsutum A-subgenome and six to the D-subgenome. Four of the 11 18S–28S rDNA loci inG. hirsutum could not be accounted for in its presumed diploid progenitors, as both A-genome species has three loci and both D-genome species had four.G. hirsutum has two 5S rDNA loci, both of which are syntenic to major 18S–28S rDNA loci. All four of the diploid genomes wer examined contained a single 5S locus. InG. herbaceum (A₁) andG. thurberi (D₁), the 5S locus is syntenic to a major 18S–28S locus, but inG. arboreum (A₂) andG. raimondii (D₅), the proposed D-genome progenitor ofG. hirsutum, the 5S loci are syntenic tominor and intermediate 18S–28S loci, respecitively. The multiplicity, variation in size and site number, and lack of additivity between the tetraploid species and its putative diploid ancestors indicate that the behavior of rDNA loci in cotton is nondogmatic, and considerably more complex and dynamic than previously envisioned. The relative variability of 18S–28S rDNA loci versus 5S rDNA loci suggests that the behavior of tandem repearts can differ widely. Edited by: R. Appels     

Cladistic analysis of 5S rRNA and 16S rRNA secondary and primary structure—The evolution of eukaryotes and their relation to archaebacteria

Summary The secondary structure of 5S rRNA has been elucidated by a cladistic analysis resulting in minimal models for eukaryotes, eubacteria, and halophilic-methanogenic archaebacteria, as well as for an ur-5S rRNA. This ancestor of all present-day 5S rRNA molecules is compared with an ur-tRNA and can be fitted into a tRNA-like structure allowing tertiary-structure interactions at the equivalent positions. A phylogenetic analysis of eukaryotic 5SrRNA and 16S rRNA sequences confirms particular monophyletic taxa: rhodophytes (red algae), chlorobionts (green algae and plants), metazoans (multicellular animals), euglenozoans (euglenids and trypanosomatids), a group of zygomycetes (excluding Kickxellales), a group of ascomycetes (excluding Protomycetales), two distinct groups of basidiomycetes, and a group consisting of phaeophyceans (brown algae) and oomycetes (water molds). The Euglenozoa show a distinct relation to the Eumycota (true fungi) and Metazoa. An analysis of archaebacterial sequences substantiates the paraphyletic nature of this third urkingdom defining the eubacteria as a sister group of the halophile-methanogens and defining the eukaryotes as a sister group of a particular lineage of the eocytes/sulfur-dependents. The latter fact implies that even the eocytes/sulfur-dependent archaebacteria are paraphyletic.Presented at the FEBS Symposium on Genome Organization and Evolution, held in Crete, Greece, September 1–5, 1986Dedicated to the memory of Erik Huysmans who died on July 8, 1986, at the age of 29.     

Identification and Characterization of a Mucilaginibacter sp. Strain QM49 β-Glucosidase and Its Use in the Production of the Pharmaceutically Active Minor Ginsenosides (S)-Rh1 and (S)-Rg2

Here, we isolated and characterized a new ginsenoside-transforming β-glucosidase (BglQM) from Mucilaginibacter sp. strain QM49 that shows biotransformation activity for various major ginsenosides. The gene responsible for this activity, bglQM, consists of 2,346 bp and is predicted to encode 781 amino acid residues. This enzyme has a molecular mass of 85.6 kDa. Sequence analysis of BglQM revealed that it could be classified into glycoside hydrolase family 3. The enzyme was overexpressed in Escherichia coli BL21(DE3) using a maltose binding protein (MBP)-fused pMAL-c2x vector system containing the tobacco etch virus (TEV) proteolytic cleavage site. Overexpressed recombinant BglQM could efficiently transform the protopanaxatriol-type ginsenosides Re and Rg₁ into (S)-Rg₂ and (S)-Rh₁, respectively, by hydrolyzing one glucose moiety attached to the C-20 position at pH 8.0 and 30°C. The K_m values for p-nitrophenyl-β-d-glucopyranoside, Re, and Rg₁ were 37.0 ± 0.4 μM and 3.22 ± 0.15 and 1.48 ± 0.09 mM, respectively, and the V_max values were 33.4 ± 0.6 μmol min⁻¹ mg⁻¹ of protein and 19.2 ± 0.2 and 28.8 ± 0.27 nmol min⁻¹ mg⁻¹ of protein, respectively. A crude protopanaxatriol-type ginsenoside mixture (PPTGM) was treated with BglQM, followed by silica column purification, to produce (S)-Rh₁ and (S)-Rg₂ at chromatographic purities of 98% ± 0.5% and 97% ± 1.2%, respectively. This is the first report of gram-scale production of (S)-Rh₁ and (S)-Rg₂ from PPTGM using a novel ginsenoside-transforming β-glucosidase of glycoside hydrolase family 3.     

Characterization and Genetic Study of the Ovine α S2 -Casein (CSN1S2) Allele B

An interesting and quite complex protein pattern has been described at ovine milk proteins but the genetic control of the variation observed was assessed only in few cases. The aim of this work was to characterize the ovine α _s2 -casein (CSN1S2) B variant, first observed in the Italian Gentile di Puglia, a fine-wooled ovine breed, and to investigate its occurrence in two further breeds, the Sarda and Camosciata, which are the most widespread dairy breeds in Italy. The B variant differs from the most common form A with two amino acid exchanges: Asp₇₅ → Tyr₇₅ and Ile₁₀₅ → Val₁₀₅. The first substitution, resulting in a loss of a negative charge, is responsible for the higher isoelectric point of the B protein variant, which allows its detection by isoelectric focusing electrophoresis (IEF). The occurrence of CSN1S2*B in Sarda and Comisana was demonstrated. Since the Asp₇₅ → Tyr₇₅ substitution modifies the protein electric charge, milk properties may result affected to some extent.     

Enzymatic esterification of lavandulol – a partial kinetic resolution of (S)-lavandulol and preparation of optically enriched (R)-lavandulyl acetate

The asymmetric esterification of the racemic primary alcohol lavandulol was achieved using lipase B from Candida antarctica and acetic acid as acyl donor in 80% yield. The enantioselectivity of the process was characterised, and a preparative resolution of 25 mM racemic lavandulol, stopped at approx. 55% conversion, yielded (S)-lavandulol in 42% yield and 52% e.e. and (R)-lavandulyl acetate in 51% yield and 48% e.e.     

Isolation of Sporothrix schenckii From the Claws of Domestic Cats (Indoor and Outdoor) and in Captivity in São Paulo (Brazil)

Sporotrichosis is a subcutaneous mycosis and is also a zoonosis (sapro- and anthropozoonosis). The objective of the present study was to determine the occurrence of sporotrichosis in domestic cats and in wild or exotic felines in captivity through the isolation of Sporothrix spp. from claw impressions in a culture medium. The samples included 132 felines, of which 120 (91.0 %) were domestic cats, 11 (8.3 %) were wild felines, and one (0.7 %) was an exotic felid. Twenty-one (17.5 %) were outdoor cats. Of the total, 89 (67.4 %) had contact with other animals of the same species. It was possible to isolate Sporothrix schenckii from the claws of one (0.7 %) of the felids probed; this animal exhibited generalised sporotrichosis and had infected a female veterinarian. The potential pathogenic agents Microsporum canis and Malassezia pachydermatis were isolated in 12.1 and 5.3 % of the animals, respectively. The following anemophilous fungi, which were considered to be contaminants, were also isolated: Penicillium sp. (28 or 21.2 %), Aspergillus sp. (13 or 9.8 %), Rhodotorula sp. (5 or 3.8 %), Candida sp. (5 or 3.8 %), Trichoderma sp. (1 or 0.7 %), and Acremonium sp. (1 or 0.7 %). Due to the low magnitude of occurrence (0.7 %) of Sporothrix in feline claws, the potential of the cats evaluated in this study to be sources of infection in the city of São Paulo is considerably low.     

Synthesis of (S)-(—)-Vertinolide

(S)-(?)-Vertinolide 1 was synthesized via the tetronic acid derivative 6 from (S)-(?)-tetrahydro-2-methyl-5-oxo-2-furancarboxylic acid 3. (±)-Vertinolide was also synthesized from (±)-3.     

Absorption and Translocation of O-Ethyl S,S-Diphenyl Phosphorodithiolate (Hinosan®) in Rice Plants

Absorption and translocation of (O-ethyl S,S-diphenyl phosphorodithiolate (Hinosan) in rice plants were studied by means of techniques of gas-liquid chromatography, radioautograph and ³²P-radioactivity determination. ³²P-labeled Hinosan was used in the present study. Hinosan on the surface of a leaf and on a glass plate was dissipated in a much slower rate than the other phosphorus pesticides tested. Hinosan was chemically transformed to a small extent after taken up into the plant tissues and largely remained in the local region. Up- and downward translocation of Hinosan occurred slightly in the ride seedlings. Translocation and accumulation of Hinosan were also studied concerning with growth stage of rice plants, such as the seedling, the milk-ripening, and the ripening stage. Accumulation in grains was in most cases found to be less than the limit of determination. Translocation of Hinosan was discussed in relation to physiological conditions of rice plants.     

Photobromination of 1,5-Anhydro-2,3-O-isopropylidene-β-d-ribofuranose and Synthesis of (5R) and (5S)-(5-2H1)-d-Riboses

The photobromination of 1,5-anhydro-2,3-O-isopropylidene-β-d-ribofuranose gave the corresponding (5S)-5-bromo compound. The reduction of the bromide with triphenyltindeuteride gave (5S)-(5-²H₁)-1,5-anhydro-2,3-O-isopropylidene-β-d-ribofuranose, with a chiral purity of 76% at C-5, which was converted to (5R)- and (5S)-(5-²H₁)-d-riboses and other ribofuranose derivatives.     

Environmental variables and intertidal beach annelids of São Sebastião Channel (State of São Paulo,Brazil)

Benthic annelid communities were studied during a one-year period (August/95 to July/96) in two sectors of the beaches Engenho d'Agua and S?o Francisco, S?o Sebasti?o Channel (S?o Paulo, Brazil), where the substrate is composed by a mixture of sand and rock fragments. Abiotic parameters such as salinity of interstitial water and sediment properties were used to characterize the environment. The polychaetes were well represented in the two sectors and their distribution was related with sediment type. The density of individuals and the number of taxa was higher at S?o Francisco, while the diversity and the evenness were higher at Engenho d'Agua. This difference can be a consequence of organic enrichment caused by domestic input, and of the lower and more variable salinity at S?o Francisco. Due to these factors, the high density of opportunistic species, like Capitella capitata ssp., Scolelepis squamata, Laeonereis acuta and several oligochaetes, represented 75.5% of total abundance at this sector.     

Mössbauer, EPR, and MCD studies of the C9S and C42S variants of Clostridium pasteurianum rubredoxin and MCD studies of the wild-type protein

Rubredoxins contain a mononuclear iron tetrahedrally coordinated by four cysteinyl sulfurs. We have studied the wild-type protein from Clostridium pasteurianum and two mutated forms, C9S and C42S, in the oxidized and reduced states, with Mössbauer, integer-spin EPR, and magnetic circular dichroism (MCD) spectroscopies. The Mössbauer spectra of the ferric C42S and C9S mutant forms yielded zero-field splittings, D=1.2?cm^?1, that are about 40% smaller than the D-value of the wild-type protein. The ⁵⁷Fe hyperfine coupling constants were found to be ca. 8% larger than those of the wild-type proteins. The present study also revealed that the ferric wild-type protein has δ=0.24±0.01?mm/s at 4.2?K rather than δ=0.32?mm/s as reported in the literature. The Mössbauer spectra of both dithionite-reduced mutant proteins revealed the presence of two ferrous forms, A and B. These forms have isomer shifts δ=0.79?mm/s at 4.2?K, consistent with tetrahedral Fe²⁺(Cys)₃(O-R) coordination. The zero-field splittings of the two forms differ substantially; we found D=?7±1?cm^?1, E/D=0.09 for form A and D=+6.2±1.3?cm^?1, E/D=0.15 for form B. Form A exhibits a well-defined integer-spin EPR signal; from studies at X- and Q-band we obtained g _z =2.08±0.01, which is the first measured g-value for any ferrous rubredoxin. It is known from X-ray crystallographic studies that ferric C42S rubredoxin is coordinated by a serine oxygen. We achieved 75% reduction of C42S rubredoxin by irradiating an oxidized sample at 77?K with synchrotron X-rays; the radiolytic reduction produced exclusively form A, suggesting that this form represents a serine-bound Fe²⁺ site. Studies in different buffers in the pH?6–9 range showed that the A:B ratios, but not the spectral parameters of A and B, are buffer dependent, but no systematic variation of the ratio of the two forms with pH was observed. The presence of glycerol (30–50% v/v) was found to favor the B form. Previous absorption and circular dichroism studies of reduced wild-type rubredoxin have suggested d-d bands at 7400, 6000, and 3700?cm^?1. Our low-temperature MCD measurements place the two high-energy transitions at ca. 5900 and 6300?cm^?1; a third d-d transition, if present, must occur with energy lower than 3300?cm^?1. The mutant proteins have d-d transitions at slightly lower energy, namely 5730, 6100?cm^?1 in form A and 5350, 6380?cm^?1 in form B.     

The biodiversity and conservation of the birds of São Tomé and Príncipe

At present the majority of the endemic bird species occurring on São Tomé and Príncipe remain common, the rarer species being those largely confined to primary rainforest. In 1990 the dwarf olive ibis (Bostrychia bocagei), São Tomé fiscal shrike (Lanius newtoni), São Tomé short-tail (Amaurocichla bocagii) were rediscovered and in 1991 the São Tomé grosbeak (Neospiza concolor) was seen for the first time since 1888. Lowland primary forest is the only habitat on São Tomé in which all the endemic species are found. Primary forest on Príncipe remains largely unsurveyed since the beginning of the century. Due to the decline in the cocoa industry and poor infra-structure post-independence the extent of secondary forest is probably at its greatest since the late 1800s. This habitat is an important buffer zone against development for the remaining primary forest and also contains important populations of many of the endemic species, in particular the São Tomé scops owl (Otus hartlaubi), São Tomé oriole (Oriolus crassirostris) and giant weaver (Ploceus grandis). On both islands the remaining areas of primary forest need immediate protection and suitable boundaries have been designated under the Zona Ecológica plan. Fortunately, except for an important area around Lagôa Amélia, primary forest is not under immediate threat, although a variety of pressures are likely to increase. In conjunction with the protection of primary forest, a plant for managing the remaining timber resource on the islands will be a vital requirement, particularly if areas of shade forest, an important habitat for endemic bird species and a potentially valuable economic resource, are to be conserved and sustainably managed.     

Identification of novel small-molecule inhibitors of α-methylacyl-CoA racemase (AMACR; P504S) and structure-activity relationships

α-Methylacyl-CoA racemase (AMACR; P504S; EC 5.1.99.4) catalyses epimerization of 2-methylacyl-CoAs and is important for the degradation of branched-chain fatty acids and the pharmacological activation of ibuprofen and related drugs. It is also a novel drug target for prostate and other cancers. However, development of AMACR as a drug target has been hampered by the difficulties in assaying enzyme activity. Consequently, reported inhibitors have been rationally designed acyl-CoA esters, which are delivered as their carboxylate prodrugs. The novel colorimetric assay for AMACR based on the elimination of 2,4-dinitrophenolate was developed for high-throughput screening and 20,387 ‘drug-like compounds’ were screened, with a throughput of 768 compounds assayed per day. Pyrazoloquinolines and pyrazolopyrimidines were identified as novel scaffolds and investigated as AMACR inhibitors. The most potent inhibitors have IC₅₀ values of ~2 µM. The pyrazoloquinoline inhibitor 10a displayed uncompetitive inhibition, whilst 10j displayed mixed competitive inhibition. The pyrazolopyrimidine inhibitor 11k displayed uncompetitive inhibition. This is the first report of the identification of specific drug-like small-molecule AMACR inhibitors by high-throughput screening. Pyrazoloquinolines and pyrazolopyrimidines may also be useful as inhibitors of other CoA-utilizing enzymes.