cas 55721-65-8, Boc-D-isoleucine | Articles data

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Antiplasmodial activity of hydroxyethylamine analogs: Synthesis, biological activity and structure activity relationship of plasmepsin inhibitors
Malaria, particularly in endemic countries remains a threat to the human health and is the leading the cause of mortality in the tropical and sub-tropical areas. Herein, we explored new C2 symmetric hydroxyethylamine analogs as the potential inhibitors of Plasmodium falciparum (P. falciparum; 3D7) in in-vitro cultures. All the listed compounds were also evaluated against crucial drug targets, plasmepsin II (Plm II) and IV (Plm IV), enzymes found in the digestive vacuole of the P. falciparum. Analog 10f showed inhibitory activities against both the enzymes Plm II and Plm IV (Ki, 1.93 ± 0.29 μM for Plm II; Ki, 1.99 ± 0.05 μM for Plm IV). Among all these analogs, compounds 10g selectively inhibited the activity of Plm IV (Ki, 0.84 ± 0.08 μM). In the in vitro screening assay, the growth inhibition of P. falciparum by both the analogs (IC50, 2.27 ± 0.95 μM for 10f; IC50, 3.11 ± 0.65 μM for 10g) displayed marked killing effect. A significant growth inhibition of the P. falciparum was displayed by analog 12c with IC50 value of 1.35 ± 0.85 μM, however, it did not show inhibitory activity against either Plms. The hemolytic assay suggested that the active compounds selectively inhibit the growth of the parasite. Further, potent analogs (10f and 12c) were evaluated for their cytotoxicity towards mammalian HepG2 and vero cells. The selectivity index (SI) values were noticed greater than 10 for both the analogs that suggested their poor toxicity. The present study indicates these analogs as putative lead structures and could serve as crucial for the development of new drug molecules.
Kumar Singh, Amit,Rajendran, Vinoth,Singh, Snigdha,Kumar, Prashant,Kumar, Yogesh,Singh, Archana,Miller, Whelton,Potemkin, Vladimir,Poonam,Grishina, Maria,Gupta, Nikesh,Kempaiah, Prakasha,Durvasula, Ravi,Singh, Brajendra K.,Dunn, Ben M.,Rathi, Brijesh
p. 3837 - 3844
(2018/07/13)

Total synthesis of the azolemycins
The first total syntheses of newly isolated polyazole natural products azolemycins A-D, along with the synthesis of the tetra-oxazole non-natural analogue, are described.
Anderson, Zoe J.,Fox, David J.
supporting information
p. 1450 - 1454
(2016/02/03)

Design, synthesis, and in vitro antiplasmodial activity of 4-aminoquinolines containing modified amino acid conjugates
Abstract: A new series of side chain-modified 4-aminoquinolines were synthesized and screened for in vitro antiplasmodial activity against both chloroquine-sensitive (3D7) and chloroquine-resistant (K1) strains of Plasmodium falciparum. Among the series, compounds 30 and 31 showed significant inhibition of parasite growth against K1 strain of P. falciparum with IC50 values 0.28 and 0.31?μM, respectively, whereas compounds 34, 35, and 38 exhibited superior activity against K1 strain with IC50 values 0.18, 0.22, and 0.17?μM, respectively, as compared to 0.255?μM for chloroquine (CQ). All the compounds displayed good resistance factor between 1.54 and >34.48 as against 51.0 for CQ. All these analogues were found to form strong complex with hematin and inhibited the β-hematin formation in vitro, suggesting that this class of compounds act on a heme polymerization target. Overall results suggest that present series of compounds appear to be promising for further lead optimization to obtain compounds active against drug-resistant parasites. Graphical Abstract: [Figure not available: see fulltext.]
Srinivasarao, Kondaparla,Agarwal, Pooja,Srivastava, Kumkum,Haq,Puri, Sunil K.,Katti
p. 1148 - 1162
(2016/07/06)

Lipopeptides from the tropical marine cyanobacterium symploca sp.
A collection of the tropical marine cyanobacterium Symploca sp., collected near Kimbe Bay, Papua New Guinea, previously yielded several new metabolites including kimbeamides A-C, kimbelactone A, and tasihalide C. Investigations into a more polar cytotoxic fraction yielded three new lipopeptides, tasiamides C-E (1-3). The planar structures were deduced by 2D NMR spectroscopy and tandem mass spectrometry, and their absolute configurations were determined by a combination of Marfeys and chiral-phase GC-MS analysis. These new metabolites are similar to several previously isolated compounds, including tasiamide (4), grassystatins (5, 6), and symplocin A, all of which were isolated from similar filamentous marine cyanobacteria.
Mevers, Emily,Haeckl, F. P. Jake,Boudreau, Paul D.,Byrum, Tara,Dorrestein, Pieter C.,Valeriote, Frederick A.,Gerwick, William H.
p. 969 - 975
(2014/05/20)

Trichormamides A and B with antiproliferative activity from the cultured freshwater cyanobacterium Trichormus sp. UIC 10339
Two new cyclic lipopeptides, trichormamides A (1) and B (2), were isolated from the cultured freshwater cyanobacterium Trichormus sp. UIC 10339. The strain was obtained from a sample collected in Raven Lake in Northern Wisconsin. The planar structures of trichormamides A (1) and B (2) were determined using a combination of spectroscopic analyses including HRESIMS and 1D and 2D NMR experiments. The absolute configurations of the amino acid residues were assigned by the advanced Marfey's method after acid hydrolysis. Trichormamide A (1) is a cyclic undecapeptide containing two d-amino acid residues (d-Tyr and d-Leu) and one β-amino acid residue (β-aminodecanoic acid). Trichormamide B (2) is a cyclic dodecapeptide characterized by the presence of four nonstandard α-amino acid residues (homoserine, N-methylisoleucine, and two 3-hydroxyleucines) and one β-amino acid residue (β-aminodecanoic acid). Trichormamide B (2) was cytotoxic against MDA-MB-435 and HT-29 cancer cell lines with IC50 values of 0.8 and 1.5 μM, respectively.
Luo, Shangwen,Krunic, Aleksej,Kang, Hahk-Soo,Chen, Wei-Lun,Woodard, John L.,Fuchs, James R.,Swanson, Steven M.,Orjala, Jimmy
supporting information
p. 1871 - 1880
(2014/10/16)

Discovery of a pair of diastereomers as potent HDACs inhibitors: Determination of absolute configuration, biological activity comparison and computational study
Histone deacetylase inhibitors (HDACi) are still the focus of epigenetic modulator development due to their effective intervention in many pathological processes. In our previous research, a potent HDACi was designed, synthesized and validated as a promising antitumor candidate named ZYJ-34c. Enlarged scale synthesis of ZYJ-34c for further detailed research was hindered by the occurrence of a by-product, which was identified as an isomer of ZYJ-34c by HRMS and 1H NMR. Subsequent synthesis route modification and optimization revealed that these two isomers were a pair of epimers and their absolute configurations could be directly determined by our optimized synthesis routes, through which each optically pure epimer could be stereoselectively synthesized, respectively. Based on these results, we concluded that our previously reported absolute configuration of ZYJ-34c was incorrect. It is worth noting that the epimer of ZYJ-34c exhibited more potent HDACs inhibition and both in vitro and in vivo antitumor activities, and moreover, their different HDACs inhibitory activities could be rationalized by computational simulations of their binding modes in HDAC2. The Royal Society of Chemistry 2013.
Zhang, Yingjie,Inks, Elizabeth S.,Zhu, Mengyuan,Chou, C. James,Fang, Hao,Li, Minyong,Shen, Yuemao,Yi, Fan,Xu, Wenfang
p. 21106 - 21109
(2013/11/06)

Design, synthesis, and biological activity of thiazole derivatives as novel influenza neuraminidase inhibitors
A series of novel influenza neuraminidase (NA) inhibitors based on thiazole core were synthesized and evaluated for their ability to inhibit NA of influenza A virus (H3N2). All compounds were synthesized in good yields starting from commercially available 2-amino-4-thiazole-acetic ester using a suitable synthetic strategy. These compounds showed moderate inhibitory activity against influenza A NA. The most potent compound of this series is compound 4d (IC50=3.43 μM), which is about 20-fold less potent than oseltamivir, and could be used to design novel influenza NA inhibitors that exhibit increased activity based on thiazole ring.
Liu,Zhang, Lei,Gong, Jianzhi,Fang, Hao,Liu, Ailin,Du, Guanhua,Xu, Wenfang
scheme or table
p. 506 - 513
(2012/06/01)

Preparation and biological evaluation of key fragments and open analogs of scleritodermin A
The synthesis of key fragments of scleritodermin A, their assembly, and their biological evaluation as cytotoxic and anthelmintic were performed.Highlights of the synthetic route include formation of the a-ketoamide linkage and use of stereocontrolled reactions.Open analogs of this natural product were obtained using a convergent strategy.
Sellanes, Diver,Campot, Francisco,Nú?ez, Ivana,Lin, Gerardo,Espósito, Pablo,Dematteis, Sylvia,Salda?a, Jenny,Domílnguez, Laura,Manta, Eduardo,Serra, Gloria
scheme or table
p. 5384 - 5395
(2010/08/19)

Toward the total synthesis of Scleritodermin A: preparation of the C1-N15 fragment
The synthesis of the C1-N15 fragment of the marine natural product Scleritodermin A has been accomplished through a short and stereocontrolled sequence. Highlights of this route include the synthesis of the novel ACT fragment and the formation of the α-keto amide linkage by the use of a highly activated α,β-ketonitrile.
Sellanes, Diver,Manta, Eduardo,Serra, Gloria
p. 1827 - 1830
(2008/02/05)

Asymmetric, anti-selective scandium-catalyzed Sakurai additions to glyoxyamide. Applications to the syntheses of N-Boc D-alloisoleucine and D-isoleucine
An enantio- and diastereoselective Sakurai-Hosomi reaction, catalyzed by chiral scandium pyridyl-bis(oxazoline) (pybox) complexes, has been developed. Both alkyl- and aryl-substituted allylsilanes are effective coupling partners with N-phenylglyoxamide. Applications of this reaction to the asymmetric syntheses of N-Boc D-alloisoleucine and D-isoleucine are described.
Evans, David A.,Aye, Yimon,Wu, Jimmy
p. 2071 - 2073
(2007/10/03)

Exploration of the P1 SAR of aldehyde cathepsin K inhibitors.
The synthesis and biological activity of a series of aldehyde inhibitors of cathepsin K are reported. Exploration of the properties of the S(1) subsite with a series of alpha-amino aldehyde derivatives substituted at the P(1) position afforded compounds with cathepsin K IC(50)s between 52 microM and 15 nM.
Catalano, John G,Deaton, David N,Furfine, Eric S,Hassell, Annie M,McFadyen, Robert B,Miller, Aaron B,Miller, Larry R,Shewchuk, Lisa M,Willard Jr., Derril H,Wright, Lois L
p. 275 - 278
(2007/10/03)

Crystal structure and total synthesis of globomycin: Establishment of relative and absolute configurations [5]
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Kogen,Kiho,Nakayama,Furukawa,Kinoshita,Inukai
p. 10214 - 10215
(2007/10/03)

Fatty acid analogs and prodrugs
Novel derivatives of fatty acid analogs that have from one to three heteroatoms in the fatty acid moiety which can be oxygen, sulfur or nitrogen, are disclosed in which the carboxy-terminus has been modified to form various amides, esters, ketones, alcohols, alcohol esters and nitrites thereof. These compounds are useful as substrates for N-myristoyltransferase (NMT) and/or its acyl coenzyme, and as anti-viral and anti-fungal agents or pro-drugs of such agents. Illustrative of the disclosed compounds are fatty acid amino acid analogs of the structure STR1 in which x is the ethyl or t-butyl ester of an amino acid such as Gly, L-Ala, L-Ile, L-Phe, L-Trp, L-Thr or an amide such as NHCH2 C6 H5 or NH(CH2)2 C6 H5.
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(2008/06/13)

Anti-fungal agents
Compounds of the formula STR1 or pharmaceutically acceptable salts thereof wherein R1, R2, X1, X2, X3, X4, X5, X6, X7, and X8, are as set forth herein are described. These compounds are useful as agents in the treatment of fungal infections.
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(2008/06/13)

Fatty acid analogs and prodrugs
Novel derivatives of fatty acid analogs that have from one to three heteroatoms in the fatty acid moiety which can be oxygen, sulfur or nitrogen, are disclosed in which the carboxy-terminus has been modified to form various amides, esters, ketones, alcohols, alcohol esters and nitriles thereof. These compounds are useful as substrates for N-myristoyltransferase (NMT) and/or its acyl coenzyme, and as anti-viral and anti-fungal agents or pro-drugs of such agents. Illustrative of the disclosed compounds are fatty acid amino acid analogs of the structure STR1 in which X is the ethyl or t-butyl ester of an amino acid such as Gly, L--Ala, L--Ile, L--Phe, L--Trp, L--Thr or an amide such as NHCH2 C6 H5 or NH(CH2)2 C6 H5,
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(2008/06/13)

Inhibitors of farnesyl protein transferase
Inhibition of farnesyl transferase, which is an enzyme involved in ras oncogene expression, is effected by compounds of the formula their enantiomers, diastereomers, and pharmaceutically acceptable salts, prodrugs, and solvates, wherein:, ???G is ???when G is it is optionally substituted, at any available position or positions, with halo, alkyl or substituted alkyl having 1 to 20 carbon atoms, alkoxy, or a combination of these groups;, ???G1is optionally substituted, at any of the available position or positions on the ring, with halo, alkyl or substituted alkyl having 1 to 20 carbon atoms, alkoxy, aryl, aralkyl, hydroxy, alkanoyl, alkanoyloxy, amino, alkylamino, dialkylamino, alkanoylamino, thiol, alkylthio, alkylthiono, alkylsulfonyl, sulfonamido, nitro, cyano, carboxy, carbamyl, N-hydroxycarbamyl, N-alkylcarbamyl, N-dialkylcarbamyl, alkoxycarbonyl, phenyl, substituted phenyl, or a combination of these groups;, ???G2is or -NR6-CH(Q1)-;, ???J, K and L are each, independently, N, NR7, O, S or CR6with the provisos that only one of the groups J, K and L can be O or S, and at least one of the groups J or L must be N, NR7, O or S to form a fused five-membered heteroring; the bond between J and K or K and L may also form one side of a phenyl ring fused to the fused five-membered heteroring;, ???Q is is alkyl, cycloalkyl, substituted alkyl, aryl, pyrrolyl, furyl, thiophenyl, imidazolyl, oxazolyl, thiazolyl, pyrazolyl, pyrrolidyl or pyridyl;, ???Q1, A1and A2are each, independently, H, alkyl, substituted alkyl, phenyl or substituted phenyl;, ???G3is R8, -C(O)OR8, -C(O)NR8R9, -C(O)N(R10)OR8, -C(O)NHSO2R11or -CH2OR8;, ???X is -SH, -OH or -NHR12;, ???X1is -NR13-, -CH2- or -CH(NHR14)-;, ???Y and Z are each, independently, -CH2- or -C(O)-;, ???R1- R14are each, independently, H or alkyl having 1 to 20 carbon atoms;, ???R3may also be substituted alkyl or cycloalkyl; R4, R5and R11may also be aryl or aralkyl; R7, R8, R9and R10may also be aralkyl; and R12, R13and R14may also be substituted alkyl or aralkyl;, ???m is 0 or an integer from 1 to 2;, ???q is 0 or an integer from 1 to 3;, ???t is an integer from 1 to 2; and, ???the dotted line represents an optional double bond.
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(2008/06/13)

Imidazole-containing inhibitors of farnesyl protein transferase
Inhibition of farnesyl transferase, which is an enzyme involved in ras oncogene expression, is effected by compounds of the formula their enantiomers, diastereomers, and pharmaceutically acceptable salts, prodrugs, and solvates, wherein:, G is G1 is G2 is or -NR10-CH(Q1)-;, J, K and L are each, independently, N, NR9, O, S or CR10 with the provisos that only one of the groups J, K and L can be O or S, and at least one of the groups J or L must be N, NR9, O or S to form a fused five-membered heteroring; the bond between J and K or K and L may also form one side of a phenyl ring fused to the fused five-membered heteroring;, Q is aryl;, Q1, A1 and A2 are each, independently, H, alkyl, substituted alkyl, phenyl or substituted phenyl;, G3 is R11, -C(O)OR11, -C(O)NR11R12, 5-tetrazolyl, -C(O)N(R13)OR11, -C(O)NHSO2R14 or -CH2OR11;, G4 is attached at the 1, 2, 4 or 5 position and optionally substituted, at any of the available position or positions on the ring, with halo, alkyl or substituted alkyl having 1 to 20 carbon atoms, alkoxy, aryl, aralkyl, hydroxy, alkanoyl, alkanoyloxy, amino, alkylamino, dialkylamino, alkanoylamino, thiol, alkylthio, alkylthiono, alkylsulfonyl, sulfonamido, nitro, cyano, carboxy, carbamyl, N-hydroxycarbamyl, N-alkylcarbamyl, N-dialkylcarbamyl, alkoxycarbonyl, phenyl, substituted phenyl, or a combinaton of these groups;, Y and Z are each, independently, -CH2- or -C(O)-;, R1 - R14 are each, independently, H or alkyl having 1 to 20 carbon atoms;, R7, R8 and R14 may also be aryl or aralkyl, and R3, R9, R11, R12 and R13 may also be aralkyl;, m, n and p are each, independently, 0 or an integer from 1 to 2;, q is 0 or an integer from 1 to 4; and, the dotted line represents an optional double bond.
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(2008/06/13)

Synthesis of D-Alloisoleucine from L-Isoleucine and from (S)-2-Methylbutan-1-ol. Synthesis of Isostatine
Three different synthetic routes to the uncommon α-amino acid D-alloisoleucine were studied.The first was based on the stereospecific inversion of configuration of the C-2 stereogenic carbon of L-isoleucine.The second involved acetylation of L-isoleucine with epimerization at the C-2 carbon, giving a mixture of L-isoleucine and D-alloisoleucine, which was resolved enzymically with hog kidney acylase.In a new approach, an epimeric mixture of L-isoleucine and D-alloisoleucine was synthesized from (S)-2-methylbutan-1-ol and was again resolved enzymically.The D-alloisoleucine produced in these syntheses was subsequently transformed into the γ-amino acid isostatine.
Lloyd-Williams, Paul,Monerris, Patricia,Gonzalez, Isabel,Jou, Gemma,Giralt, Ernest
p. 1969 - 1974
(2007/10/02)

1,3-Diastereocontrol with Bromoallenes. Synthesis of Enantiomerically Pure β-Branched α-Amino Acids
Bromoallenes 3a and 3b derived from (D)-Serine undergo SN2' alkylation with organo copper reagents to give alkynyl amino alcohol derivatives.These compounds can be further transformed into branched enantiomerically enriched α-amino acids as, for example (L)-Isoleucine and (L)-Alloisoleucine.
D'Aniello, Fabiana,Mann, Andre,Taddei, Maurizio,Wermuth, Camille-Georges
p. 7775 - 7778
(2007/10/02)

Synthesis and properties of the eight isostatine stereoisomers
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Rinehart,Sakai,Kishore,Sullins,Li
p. 3007 - 3013
(2007/10/02)

Synthesis of new indolactam analogues by microbial conversion
Ten indolactam congeners with L-Ala, Abu, γ,δ-Δ-Nva, Nva, Nle, tert-Leu, Leu, Ile, allo-Ile. Phg instead ofL-Val in (-)-indolactam-Val, were synthesized from their seco-compounds (N-methyl-L-amino acidyl-L-tryptophonol) by microbial conversion.
Kajiyama, Shin-Ichiro,Irie, Kazuhiro,Kido, Takae,Koshimizu, Koichi,Hayashi, Hideo,Arai, Motoo
p. 5453 - 5462
(2007/10/02)

Total Synthesis of the Didemnins; III. - Synthesis of Protected (2R,3S)-Alloisoleucine and (3S,4R,5S)-Isostatine Derivatives - Amino Acids from Hydroxy Acids
(2S,3S)-2-Acetoxy-3-methylvaleric acid (3) is prepared from L-isoleucine (2) with 96percent retention of configuration.Compound 3 is converted to optically pure methyl D-alloisoleucinate (7) as its hydrochloride salt, via the methanesulfonate 5 and the azide 6 with 76percent yield and 99.9percent inversion.Subsequent protection-saponification-activation of 7, followed by reaction with the lithium enolate of methyl trimethylsilyl malonate and reduction, yields (3S,4R,5S)-N-(9-fluorenylmethoxycarbonyl)isostatine (12). (3S,4R,5S)-Isostatine is a characteristic unit of the didemnines 1.
Schmidt, Ulrich,Kroner, Matthias,Griesser, Helmut
p. 832 - 835
(2007/10/02)

Bitter Taste of Synthetic C-Terminal Tetrapeptide of Bovine β-Casein, H-Pro196-Val-Leu-Gly-Pro-Arg-Gly-Pro-Phe-Pro-Ile-Ile-Val209-OH, and Its Related Peptides
The primary structure of bovine β-casein contains the partial sequence of -Pro196-Val-Leu-Gly-Pro-Val-Arg-Gly-Pro-Phe-Pro-Ile-Ile-Val209 in the C-terminal portion.We previously reported that the synthetic C-terminal octapeptide, Arg202-Val209, is extremly bitter with its threshold value 0.004 mM, 250 times as strong as that of caffeine.To further investigate the bitter taste of the C-terminal portion of β-casein, we synthesized the C-terminal tetrapeptide, Pro196-Val209, and some its fragments.A hydrophobic hexapeptide, Pro196-Val201, was twice as bitter as caffein.The bitter taste of decapeptide, Pro200-Val209, was the same as that of Arg202-Val209.Although the tetradecapeptide, Pro196-Val209, was composed of two bitter peptides, Pro196-Val201 and Arg202-Val209, its bitter taste was weaker than that of Arg202-Val209 and its threshold value was 0.015 mM.We suggested that the increase of bitterness in peptides through the introduction of hydrophobic amino acids depended on the number of hydrophobic amino acids added.In addition, the synthetic retro analog of Arg202-Val209 (H-Val-Ile-Ile-Pro-Phe-Pro-Gly-Arg-OH) was not as bitter as Arg202-Val209.This indicated that the sequence of Arg202-Val209 is important for extreme bitterness.
Shinoda, Ichizo,Fushimi, Akira,Kato, Hironobu,Okai, Hideo,Fukui, Sazuko
p. 2587 - 2596
(2007/10/02)

Carbonic acid esters, and the preparation thereof and their use
Carbonic acid esters of the formula substituent(s) substituents(s) wherein R'1 is lower alkyl which may have substituent)s) selected from the group of halogen, lower alkoxy and aryloxy, or ar(lower)-alkyl which may have substituents)s) selected from the group of lower alkoxy, halogen, nitro and cyano, and R'2 is benzotriazolyl which may have halogen; or a group represented by the formula: STR1 wherein Y' and Z' are each cyano, nitro, carbamoyl, esterified carboxy, lower alkanoyl, aroyl or disubstituted carbamoyl; provided that when R'2 is a group represented by the formula: STR2 wherein Y' and Z' are each cyano, nitro, carbamoyl or esterified carboxy, R'1 is ar(lower) alkyl having substituent(s) selected from the group of lower alkoxy, halogen, nitro and cyano. A process for the protection of amino and/or imino groups in compounds containing them by reacting them with the aforementioned esters is also disclosed.
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(2008/06/13)

Oxime carbonates
Novel carbonic acid esters are disclosed which are useful in a process for introducing esterified carboxy-type protective groups on amino and/or imino groups in amino and/or imino group - containing compounds for the temporary protection of said amino and/or imino groups. Additionally, processes for preparing said esters are also disclosed.
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(2008/06/13)