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Structures and antitumor activities of ten new and twenty known surfactins from the deep-sea bacterium Limimaricola sp. SCSIO 53532
Surfactins are natural biosurfactants with myriad potential applications in the areas of healthcare and environment. However, surfactins were almost exclusively produced by the bacterium Bacillus species in previous reported literatures, together with difficulty in isolating pure monomer, which resulted in making extensive effort to remove duplication and little discovery of new surfactins in recent years. In the present study, the result of Molecular Networking indicated that Limimaricola sp. SCSIO 53532 might well be a potential resource for surfacin-like compounds based on OSMAC strategy. To search for new surfactins with significant biological activity, further study was undertaken on the strain. As a result, ten new surfactins (1–10), along with twenty known surfactins (11–30), were isolated from the ethyl acetate extract of SCSIO 53532. Their chemical structures were established by detailed 1D and 2D NMR spectroscopy, HRESIMS data, secondary ion mass spectrometry (MS/MS) analysis, and chemical degradation (Marfey's method) analysis. Cytotoxic activities of twenty-seven compounds against five human tumor cell lines were tested, and five compounds showed significant antitumor activities with IC50 values less than 10 μM. Furtherly, analysis of structure–activity relationships revealed that the branch of side chain, the esterification of Glu or Asp residue, and the amino acid residue of position 7 possessed a great influence on antitumor activity.
Chen, Min,Chen, Rouwen,Ding, Wenping,Li, Yanqun,Tian, Xinpeng,Yin, Hao,Zhang, Si
(2022/01/11)

Enhanced carboxypeptidase efficacies and differentiation of peptide epimers
Carboxypeptidases enzymatically cleave the peptide bond of C-terminal amino acids. In humans, it is involved in enzymatic synthesis and maturation of proteins and peptides. Carboxypeptidases A and Y have difficulty hydrolyzing the peptide bond of dipeptides and some other amino acid sequences. Early investigations into different N-blocking groups concluded that larger moieties increased substrate susceptibility to peptide bond hydrolysis with carboxypeptidases. This study conclusively demonstrates that 6-aminoquinoline-N-hydroxysuccimidyl carbamate (AQC) as an N-blocking group greatly enhances substrate hydrolysis with carboxypeptidase. AQC addition to the N-terminus of amino acids and peptides also improves chromatographic peak shapes and sensitivities via mass spectrometry detection. These enzymes have been used for amino acid sequence determination prior to the advent of modern proteomics. However, most modern proteomic methods assume that all peptides are comprised of L-amino acids and therefore cannot distinguish L-from D-amino acids within the peptide sequence. The majority of existing methods that allow for chiral differentiation either require synthetic standards or incur racemization in the process. This study highlights the resistance of D-amino acids within peptides to enzymatic hydrolysis by Carboxypeptidase Y. This stereoselectivity may be advantageous when screening for low abundance peptide stereoisomers.
Sung, Yu-Sheng,Putman, Joshua,Du, Siqi,Armstrong, Daniel W.
(2022/01/29)

Cyclic Tetrapeptides with Synergistic Antifungal Activity from the Fungus Aspergillus westerdijkiae Using LC-MS/MS-Based Molecular Networking
Fungal natural products play a prominent role in the development of pharmaceuticalagents. Two new cyclic tetrapeptides (CTPs), westertide A (1) and B (2), with eight known compounds (3-10) were isolated from the fungus Aspergillus westerdijkiae guided by
Chen, Baosong,Dai, Huanqin,Han, Junjie,Li, Erwei,Liu, Hongwei,Lyu, Zhitang,Song, Fuhang,Sun, Jingzu,Wang, Hanying,Wang, Tao,Wang, Wenzhao,Zhang, Rui
(2022/02/17)

Inherently chiral dialkyloxy-calix[4]arene acetic acids as enantiodiscriminating additives for high-performance liquid chromatography separation of d,l-amino acids
Inherently chiral dialkyloxy-calix[4]arene acetic acids with asymmetric placement of substituents on the lower rim of the macrocycle were first studied as enantiodiscriminating additives to the mobile phase MeCN/H2O/HCOOH (75/25/0.02 by volume) in the high-performance liquid chromatography (HPLC) separation of d,l-alanine and d,l-valine on the achiral stationary phase ZORBAX Original CN. The dependence of enantio-binding properties on the position of alkyl groups is demonstrated. The highest resolution (1.65) and enantioselectivity (1.80) were obtained for the 1,2-dipropyloxy-calix[4]arene acetic acid.
Kalchenko, Olga I.,Trybrat, Oleksandr O.,Yesypenko, Oleksandr A.,Dyakonenko, Viktoriya V.,Shishkina, Svitlana V.,Kalchenko, Vitali I.
p. 722 - 730
(2021/08/26)

Direct monitoring of biocatalytic deacetylation of amino acid substrates by1H NMR reveals fine details of substrate specificity
Amino acids are key synthetic building blocks that can be prepared in an enantiopure form by biocatalytic methods. We show that thel-selective ornithine deacetylase ArgE catalyses hydrolysis of a wide-range ofN-acyl-amino acid substrates. This activity was revealed by1H NMR spectroscopy that monitored the appearance of the well resolved signal of the acetate product. Furthermore, the assay was used to probe the subtle structural selectivity of the biocatalyst using a substrate that could adopt different rotameric conformations.
De Cesare, Silvia,McKenna, Catherine A.,Mulholland, Nicholas,Murray, Lorna,Bella, Juraj,Campopiano, Dominic J.
supporting information
p. 4904 - 4909
(2021/06/16)

Leveraging Peptaibol Biosynthetic Promiscuity for Next-Generation Antiplasmodial Therapeutics
Malaria remains a worldwide threat, afflicting over 200 million people each year. The emergence of drug resistance against existing therapeutics threatens to destabilize global efforts aimed at controlling Plasmodium spp. parasites, which is expected to leave vast portions of humanity unprotected against the disease. To address this need, systematic testing of a fungal natural product extract library assembled through the University of Oklahoma Citizen Science Soil Collection Program has generated an initial set of bioactive extracts that exhibit potent antiplasmodial activity (EC50 25 μM, selectivity index > 250). The unique chemodiversity afforded by these fungal isolates serves to unlock new opportunities for translating peptaibols into a bioactive scaffold worthy of further development.
Lee, Jin Woo,Collins, Jennifer E.,Wendt, Karen L.,Chakrabarti, Debopam,Cichewicz, Robert H.
supporting information
p. 503 - 517
(2021/03/01)

Structure revision of isocereulide A, an isoform of the food poisoning emetic Bacillus cereus toxin cereulide
The emetic Bacillus cereus toxin cereulide presents an enormous safety hazard in the food industry, inducing emesis and nausea after the consumption of contaminated foods. Additional to cereulide itself, seven structurally related isoforms, namely the isocereulides A-G, have already been elucidated in their chemical structure and could further be identified in B. cereus contaminated food samples. The newly performed isolation of isocereulide A allowed, for the first time, 1D- and 2D-NMR spectroscopy of a biosynthetically produced isocereulide, revealing results that contradict previous assumptions of an L-O-Leu moiety within its chemical structure. By furthermore applying posthydrolytical dipeptide analysis, amino acid and α-hydroxy acid analysis by means of UPLC-ESITOF- MS, as well as MSn sequencing, the structure of previously reported isocereulide A could be corrected. Instead of the L-O-Leu as assumed to date, one L-O-Ile unit could be verified in the cyclic dodecadepsipeptide, revising the structure of isocereulide A to [(D-O-Leu-D-Ala-L-O-Val-L-Val)2(DO- Leu-D-Ala-L-O-Ile-L-Val)].
Ehling-Schulz, Monika,Hofmann, Thomas F.,Kranzler, Markus,Stark, Timo D.,Walser, Veronika
supporting information

(2021/05/31)

Powerful Steroid-Based Chiral Selector for High-Throughput Enantiomeric Separation of α-Amino Acids Utilizing Ion Mobility-Mass Spectrometry
Stereospecific recognition of amino acids (AAs) plays a crucial role in chiral biomarker-based diagnosis and prognosis. Separation of AA enantiomers is a long and tedious task due to the requirement of AA derivatization prior to the chromatographic or electrophoretic steps which are also time-consuming. Here, a mass-tagged chiral selector named [d0]/[d5]-estradiol-3-benzoate-17β-chloroformate ([d0]/[d5]-17β-EBC) with high reactivity and good enantiomeric resolution in regard to AAs was developed. After a quick and easy chemical derivatization step of AAs using 17β-EBC as the single chiral selector before ion mobility-mass spectrometry analysis, good enantiomer separation was achieved for 19 chiral proteinogenic AAs in a single analytical run (～2 s). A linear calibration curve of enantiomeric excess was also established using [d0]/[d5]-17β-EBC. It was demonstrated to be capable of determining enantiomeric ratios down to 0.5% in the nanomolar range. 17β-EBC was successfully applied to investigate the absolute configuration of AAs among peptide drugs and detect trace levels of-AAs in complex biological samples. These results indicated that [d0]/[d5]-17β-EBC may contribute to entail a valuable step forward in peptide drug quality control and discovering chiral disease biomarkers.
Li, Yuling,Zhou, Bowen,Wang, Keke,Zhang, Jing,Sun, Wenjian,Zhang, Li,Guo, Yinlong
p. 13589 - 13596
(2021/10/21)

Genomics-driven discovery of a new cyclodepsipeptide from the guanophilic fungusAmphichorda guana
Two potential non-ribosomal peptide synthetases (NRPSs) were identified in the genome of a guanophilic fungusAmphichorda guanaby bioinformatics analysis and gene knockout experiments. Liquid chromatography coupled with mass spectrometry (LC-MS) guided isolation led to the discovery of a new cyclodepsipeptide isaridin H (1) and seven known analogs, desmethylisaridin E (2), isaridin E (3), isariin A (4), iso-isariin B (5), iso-isariin D (6), isariin E (7), and nodupetide (8). The absolute configuration of isaridin H (1) was achieved by Marfey's method. Isaridin H (1) showed significant antifungal activity againstBotrytis cinereaandAlternaria solani.
Liang, Min,Lyu, Hai-Ning,Ma, Zi-Ying,Li, Er-Wei,Cai, Lei,Yin, Wen-Bing
p. 1960 - 1964
(2021/03/16)

Structures and Biosynthetic Pathway of Coprisamides C and D, 2-Alkenylcinnamic Acid-Containing Peptides from the Gut Bacterium of the Carrion Beetle Silpha perforata
Coprisamides C and D (1 and 2) were isolated from a gut bacterium, Micromonospora sp. UTJ3, of the carrion beetle Silpha perforata. Based on the combined analysis of UV, MS, and NMR spectral data, the planar structures of 1 and 2 were elucidated to be unreported derivatives of coprisamides A and B, cyclic depsipeptides bearing a 2-alkenylcinnamic acid unit and the unusual amino acids β-methylaspartic acid and 2,3-diaminopropanoic acid. The absolute configuration of 1 was determined using the advanced Marfey's method, phenylglycine methyl ester derivatization, and J-based configuration analysis. The biosynthetic gene clusters for the coprisamides were investigated based on genomic data from coprisamide-producing strains Micromonospora sp. UTJ3 and Streptomyces sp. SNU533. Coprisamide C (1) was active against the Mycobacterium tuberculosis mc26230 strain.
Shin, Yern-Hyerk,Ban, Yeon Hee,Kim, Tae Ho,Bae, Eun Seo,Shin, Jongheon,Lee, Sang Kook,Jang, Jichan,Yoon, Yeo Joon,Oh, Dong-Chan
(2021/02/26)

Komesuamide and odopenicillatamide, two linear lipopeptides from the marine cyanobacterium Caldora penicillata
The linear lipopeptides komesuamide (1) and odopenicillatamide (2) were isolated from Caldora penicillata a marine cyanobacterium collected in Okinawa. The structures of these compounds were established by spectroscopic analyses, and the absolute configurations were determined by HPLC analyses of the acid hydrolysates. Both compounds showed glucose uptake activity at 40 μM in cultured L6 myotubes.
Ozaki, Kaori,Jinno, Atsuhide,Natsume, Noriyuki,Sumimoto, Shimpei,Iwasaki, Arihiro,Suenaga, Kiyotake,Teruya, Toshiaki
(2021/04/05)

Motobamide, an Antitrypanosomal Cyclic Peptide from a Leptolyngbya sp. Marine Cyanobacterium
Motobamide (1), a new cyclic peptide containing a C-prenylated cyclotryptophan residue, was isolated from a marine Leptolyngbya sp. cyanobacterium. Its planar structure was established by spectroscopic and MS/MS analyses. The absolute configuration was elucidated based on a combination of chemical degradations, chiral-phase HPLC analyses, spectroscopic analyses, and computational chemistry. Motobamide (1) moderately inhibited the growth of bloodstream forms of Trypanosoma brucei rhodesiense (IC50 2.3 μM). However, it exhibited a weaker cytotoxicity against normal human cells (IC50 55 μM).
Iwasaki, Arihiro,Jeelani, Ghulam,Kurisawa, Naoaki,Matsubara, Teruhiko,Nozaki, Tomoyoshi,Sato, Toshinori,Suenaga, Kiyotake,Suzuki, Ryota,Takahashi, Hiroki
p. 1649 - 1655
(2021/05/29)

A new amide from the marine sponge Haliclona baeri
A new amide, baeriamide (1), along with nine known diketopiperazines (2-10), was isolated from the marine sponge Haliclona baeri. Their structures were identified by the means of UV, IR, MS and NMR. The absolute configuration of 1 was established by Marfey’s method and comparing the specific optical rotation with the known compound HCO-Val-Gly methyl ester. Compound 1 was derived from dehydration of formylated L-valine with γ-amino-butanoic acid methyl ester. Compounds 2-10 were isolated from the genus of Haliclona for the first time. The absolute confirmation of 7 was confirmed first by the means of single-crystal X-ray diffraction. The cytotoxic, antibacterial, antiviral and antifouling activities of these compounds were also tested. However, none of them exhibited significant bioactivities.
Cui, Le-Zhi,Lei, Yu,Liao, Xiao-Jian,Wang, Can-Bin,Xiao, Yan-Fang,Xu, Jia-Yi,Xu, Shi-Hai,Zhao, Bing-Xin
supporting information

(2021/07/06)

Argicyclamides A-C Unveil Enzymatic Basis for Guanidine Bis-prenylation
Guanidine prenylation is an outstanding modification in alkaloid and peptide biosynthesis, but its enzymatic basis has remained elusive. We report the isolation of argicyclamides, a new class of cyanobactins with unique mono- and bis-prenylations on guanidine moieties, from Microcystis aeruginosa NIES-88. The genetic basis of argicyclamide biosynthesis was established by the heterologous expression and in vitro characterization of biosynthetic enzymes including AgcF, a new guanidine prenyltransferase. This study provides important insight into the biosynthesis of prenylated guanidines and offers a new toolkit for peptide modification.
Balloo, Nandani,Fujita, Kei,Matsuda, Kenichi,Okino, Tatsufumi,Phan, Chin-Soon,Wakimoto, Toshiyuki
supporting information
p. 10083 - 10087
(2021/07/26)

Method for photolysis of amido bonds
The invention discloses a method for photo-splitting amido bonds, wherein the method is mild in reaction condition and can realize splitting of amido bonds by using illumination. The method for photo-splitting the amido bonds comprises the following steps: reacting 2,4-dinitrofluorobenzene with an amino group of a substance which contains alpha amino acid at the tail end and is shown as a structural formula I to generate a compound 1 represented by a structural formula II; and under light irradiation, carrying out amido bond cleavage reaction on the compound 1, wherein R1 is a side chain group of alpha-amino acid, and R2 is aryl, aliphatic hydrocarbon, -CH(R)-COOH or polypeptide.
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Paragraph 0046; 0048-0049; 0102-0105

(2021/06/26)

Isolation, Structure Determination, and Total Synthesis of Hoshinoamide C, an Antiparasitic Lipopeptide from the Marine Cyanobacterium Caldora penicillata
Hoshinoamide C (1), an antiparasitic lipopeptide, was isolated from the marine cyanobacterium Caldora penicillata. Its planar structure was elucidated by spectral analyses, mainly 2D NMR, and the absolute configurations of the α-amino acid moieties were determined by degradation reactions followed by chiral-phase HPLC analyses. To clarify the absolute configuration of an unusual amino acid moiety, we synthesized two possible diastereomers of hoshinoamide C and determined its absolute configuration based on a comparison of their spectroscopic data with those of the natural compound. Hoshinoamide C (1) did not exhibit any cytotoxicity against HeLa or HL60 cells at 10 μM, but inhibited the growth of the parasites responsible for malaria (IC50 0.96 μM) and African sleeping sickness (IC50 2.9 μM).
Iwasaki, Arihiro,Ohtomo, Keisuke,Kurisawa, Naoaki,Shiota, Ikuma,Rahmawati, Yulia,Jeelani, Ghulam,Nozaki, Tomoyoshi,Suenaga, Kiyotake
p. 126 - 135
(2021/01/13)

Semi-rational hinge engineering: modulating the conformational transformation of glutamate dehydrogenase for enhanced reductive amination activity towards non-natural substrates
The active site is the common hotspot for rational and semi-rational enzyme activity engineering. However, the active site represents only a small portion of the whole enzyme. Identifying more hotspots other than the active site for enzyme activity engineering should aid in the development of biocatalysts with better catalytic performance. Glutamate dehydrogenases (GluDHs) are promising and environmentally benign biocatalysts for the synthesis of valuable chirall-amino acids by asymmetric reductive amination of α-keto acids. GluDHs contain an inter-domain hinge structure that facilitates dynamic reorientations of the domains relative to each other. Such hinge-bending conformational motions of GluDHs play an important role in regulating the catalytic activity. Thus, the hinge region represents a potential hotspot for catalytic activity engineering for GluDHs. Herein, we report semi-rational activity engineering of GluDHs with the hinge region as the hotspot. Mutants exhibiting significantly improved catalytic activity toward several non-natural substrates were identified and the highest activity increase reached 104-fold. Molecular dynamics simulations revealed that enhanced catalytic activity may arise from improving the open/closed conformational transformation efficiency of the protein with hinge engineering. In the batch production of three valuablel-amino acids, the mutants exhibited significantly improved catalytic efficiency, highlighting their industrial potential. Moreover, the catalytic activity of several active site tailored GluDHs was also increased by hinge engineering, indicating that hinge and active site engineering are compatible. The results show that the hinge region is a promising hotspot for activity engineering of GluDHs and provides a potent alternative for developing high-performance biocatalysts toward chirall-amino acid production.
Liu, Yayun,Meng, Lijun,Wu, Jianping,Yang, Lirong,Yin, Xinjian,Zhou, Haisheng
p. 3376 - 3386
(2020/06/09)

Bioelectrocatalytic Conversion from N2 to Chiral Amino Acids in a H2/α-Keto Acid Enzymatic Fuel Cell
Enzymatic electrosynthesis is a promising approach to produce useful chemicals with the requirement of external electrical energy input. Enzymatic fuel cells (EFCs) are devices to convert chemical energy to electrical energy via the oxidation of fuel at the anode and usually the reduction of oxygen or peroxide at the cathode. The integration of enzymatic electrosynthesis with EFC architectures can simultaneously result in self-powered enzymatic electrosynthesis with more valuable usage of electrons to produce high-value-added chemicals. In this study, a H2/α-keto acid EFC was developed for the conversion from chemically inert nitrogen gas to chiral amino acids, powered by H2 oxidation. A highly efficient cathodic reaction cascade was first designed and constructed. Powered by an applied voltage, the cathode supplied enough reducing equivalents to support the NH3 production and NADH recycling catalyzed by nitrogenase and diaphorase. The produced NH3 and NADH were reacted in situ with leucine dehydrogenase (LeuDH) to generate l-norleucine with 2-ketohexanoic acid as the NH3 acceptor. A 92% NH3 conversion ratio and 87.1% Faradaic efficiency were achieved. On this basis, a H2-powered fuel cell with hyper-thermostable hydrogenase (SHI) as the anodic catalyst was combined with the cathodic reaction cascade to form the H2/α-keto acid EFC. After 10 h of reaction, the concentration of l-norleucine achieved 0.36 mM with >99% enantiomeric excess and 82% Faradaic efficiency. From the broad substrate scope and the high enzymatic enantioselectivity of LeuDH, the H2/α-keto acid EFC is an energy-efficient alternative to electrochemically produce chiral amino acids for biotechnology applications.
Cai, Rong,Chen, Hsiaonung,Chen, Hui,Dong, Fangyuan,Minteer, Shelley D.,Prater, Matthew B.
supporting information
p. 4028 - 4036
(2020/03/11)

Homogeneous palladium-catalyzed enantioselective hydrogenation of 5-methylenhydantoin for the synthesis of L-Valine
In this article, we present the development of a synthetic methodology based on homogeneous catalysis for the preparation of enantioenriched L-Valine aminoacid. The enantioselective hydrogenation of 5-methylenhydantoin has been developed through broad screenings of chiral ligands, metal precursors and reaction conditions including scale-up experiments and recyclability studies. A palladium catalyzed asymmetric hydrogenation of 5-methylenhydantoin afforded the corresponding hydrogenated product in a 70% enantiomeric excess using a substrate/catalyst ratio of 500/1. A partial racemization was observed upon hydrolysis and recovery of L-Valine.
Agbossou-Niedercorn, Francine,Bellière-Baca, Virginie,Hayouni, Safa,Michon, Christophe,Morvan, Didier
supporting information

(2020/10/18)

Krisynomycins, Imipenem Potentiators against Methicillin-Resistant Staphylococcus aureus, Produced by Streptomyces canus
A reinvestigation of the acetone extract of the strain CA-091830 of Streptomyces canus, producer of the imipenem potentiator krisynomycin, resulted in the isolation of two additional analogues, krisynomycins B (1) and C (2), with different chlorination patterns. Genome sequencing of the strain followed by detailed bioinformatics analysis led to the identification of the corresponding biosynthetic gene cluster (BGC) of this cyclic nonribosomal peptide family. The planar structure of the new molecules was determined using HRMS, ESI-qTOF-MS/MS, and 1D and 2D NMR data. Their absolute configuration was proposed using a combination of Marfey's and bioinformatic BGC analyses. The krisynomycins displayed weak to negligible antibiotic activity against methicillin-resistant Staphylococcus aureus (MRSA), which was significantly enhanced when tested in combination with sublethal concentrations of imipenem. The halogenation pattern plays a key role in the antimicrobial activity and imipenem-potentiating effects of the compounds, with molecules having a higher number of chlorine atoms potentiating the effect of imipenem at lower doses.
De La Cruz, Mercedes,Genilloud, Olga,González, Ignacio,Martín, Jesús,Oves-Costales, Daniel,Pérez-Bonilla, Mercedes,Reyes, Fernando,Vicente, Francisca
p. 2597 - 2606
(2020/10/12)

Pagoamide A, a Cyclic Depsipeptide Isolated from a Cultured Marine Chlorophyte, Derbesia sp., Using MS/MS-Based Molecular Networking
A thiazole-containing cyclic depsipeptide with 11 amino acid residues, named pagoamide A (1), was isolated from laboratory cultures of a marine Chlorophyte, Derbesia sp. This green algal sample was collected from America Samoa, and pagoamide A was isolated using guidance by MS/MS-based molecular networking. Cultures were grown in a light- and temperature-controlled environment and harvested after several months of growth. The planar structure of pagoamide A (1) was characterized by detailed 1D and 2D NMR experiments along with MS and UV analysis. The absolute configurations of its amino acid residues were determined by advanced Marfey's analysis following chemical hydrolysis and hydrazinolysis reactions. Two of the residues in pagoamide A (1), phenylalanine and serine, each occurred twice in the molecule, once in the d- and once in the l-configuration. The biosynthetic origin of pagoamide A (1) was considered in light of other natural products investigations with coenocytic green algae.
Cottrell, Garrison W.,Fang, Fang,Gerwick, Lena,Gerwick, William H.,Glukhov, Evgenia,Guan, Huashi,Kim, Hyunwoo,Leao, Tiago,Li, Yueying,Mao, Huanru Henry,Murray, Thomas F.,Pierce, Marsha L.,Yu, Hao-Bing,Zhang, Chen,Zhang, Yi
supporting information

(2020/01/31)

Iheyamides A-C, Antitrypanosomal Linear Peptides Isolated from a Marine Dapis sp. Cyanobacterium
Iheyamides A (1), B (2), and C (3), new linear peptides, were isolated from a marine Dapis sp. cyanobacterium. Their structures were elucidated by spectroscopic analyses and degradation reactions. Iheyamide A (1) showed moderate antitrypanosomal activities against Trypanosoma brucei rhodesiense and Trypanosoma brucei brucei (IC50 = 1.5 μM), but the other two analogues, iheyamides B (2) and C (3), did not (IC50 > 20 μM, respectively). The structure-activity relationship clarified that an isopropyl-O-Me-pyrrolinone moiety was necessary for the antitrypanosomal activity. Furthermore, the cytotoxicity of 1 against normal human cells, WI-38, was 10 times weaker than its antitrypanosomal activity (IC50 = 18 μM).
Kurisawa, Naoaki,Iwasaki, Arihiro,Jeelani, Ghulam,Nozaki, Tomoyoshi,Suenaga, Kiyotake
p. 1684 - 1690
(2020/06/08)

Preparation and characterization of a new open-tubular capillary column for enantioseparation by capillary electrochromatography
In order to use the enantioseparation capability of cationic cyclodextrin and to combine the advantages of capillary electrochromatography (CEC) with open-tubular (OT) column, in this study, a new OT-CEC, coated with cationic cyclodextrin (1-allylimidazolium-β-cyclodextrin [AI-β-CD]) as chiral stationary phase (CSP), was prepared and applied for enantioseparation. Synthesized AI-β-CD was characterized by infrared (IR) spectrometry and mass spectrometry (MS). The preparation conditions for the AI-β-CD-coated column were optimized with the orthogonal experiment design L9(34). The column prepared was characterized by scanning electron microscopy (SEM) and elemental analysis (EA). The results showed that the thickness of stationary phase in the inner surface of the AI-β-CD-coated columns was about 0.2 to 0.5?μm. The AI-β-CD content in stationary phase based on the EA was approximately 2.77?mmol·m?2. The AI-β-CD-coated columns could separate all 14 chiral compounds (histidine, lysine, arginine, glutamate, aspartic acid, cysteine, serine, valine, isoleucine, phenylalanine, salbutamol, atenolol, ibuprofen, and napropamide) successfully in the study and exhibit excellent reproducibility and stability. We propose that the column, coated with AI-β-CD, has a great potential for enantioseparation in OT-CEC.
Li, Yingjie,Tang, Yimin,Qin, Shili,Li, Xue,Dai, Qiang,Gao, Lidi
p. 283 - 292
(2019/02/05)

Highly Diastereoselective Metal-Free Catalytic Synthesis of Drug-Like Spiroimidazolidinone
A four-step procedure has been developed for the synthesis of (S)-3-isopropyl-1-[(R)-1-phenylethyl)- 1,4-diazaspiro[4.5]decan-2-one with high diastereoselectivity (up to 95% de) from (S)-α-aminoisovaleric acid (L-valine). Quantum chemical computations of the synthesized compound have been performed using Gaussian 09 software package.
Jassem,Raheemah,Radhi,Alid,Jaber
p. 1598 - 1603
(2019/12/28)

Chemical structure of cichorinotoxin, a cyclic lipodepsipeptide that is produced by Pseudomonas cichorii and causes varnish spots on lettuce
Pseudomonas cichorii, which causes varnish spots on lettuce and seriously damages lettuce production during the summer season in the highland areas of Japan (e.g., Nagano and Iwate prefectures) was isolated. The structure of a toxin produced by this organism was analyzed based on the detailed evaluation of its 2D NMR and FABMS spectra, and this compound has not been reported previously. We propose the name cichorinotoxin for this toxin. In conjunction with the D or L configurations of each amino acid, which were determined by Marfey’s method, we propose the structure of cichorinotoxin to be as follows: 3-hydroxydecanoyl-(Z)-dhThr1-D-Pro2-D-Ala3-D-Ala4-D-Ala5-D-Val6-D-Ala7-(Z)-dhThr8-Ala9-Val10-D-Ile11-Ser12-Ala13-Val14-Ala15-Val16-(Z)-dhThr17-D-alloThr18-Ala19-L-Dab20-Ser21-Val22, and an ester linkage is present between D-alloThr18 and Val22 (dhThr: 2-aminobut-2-enoic acid; Dab: 2,4-diaminobutanoic acid). Thus, the toxin is a lipodepsipeptide with 22 amino acids. The mono- and tetraacetate derivatives and two alkaline hydrolysates, compounds A and B, were prepared. We discuss here the structure–activity relationships between the derivatives and their necrotic activities toward lettuce.
Komatsu, Hidekazu,Shirakawa, Takashi,Uchiyama, Takeo,Hoshino, Tsutomu
p. 299 - 309
(2019/02/20)

Discovery of Amantamide, a Selective CXCR7 Agonist from Marine Cyanobacteria
CXCR7 plays an emerging role in several physiological processes. A linear peptide, amantamide (1), was isolated from marine cyanobacteria, and the structure was determined by NMR and mass spectrometry. The total synthesis was achieved by solid-phase method. After screening two biological target libraries, 1 was identified as a selective CXCR7 agonist. The selective activation of CXCR7 by 1 could provide the basis for developing CXCR7-targeted therapeutics and deciphering the role of CXCR7 in different diseases.
Liang, Xiao,Luo, Danmeng,Yan, Jia-Lei,Rezaei, Mohammad A.,Salvador-Reyes, Lilibeth A.,Gunasekera, Sarath P.,Li, Chenglong,Ye, Tao,Paul, Valerie J.,Luesch, Hendrik
supporting information
p. 1622 - 1626
(2019/03/07)

Kyanamide, a new Ahp-containing depsipeptide from marine cyanobacterium Caldora penicillata
Kyanamide (1), a new depsipeptide containing 3-amino-6-hydroxy-2-piperidone moiety, was isolated from the Caldora penicillata marine cyanobacterium collected in Okinawa. Its structure was determined by spectroscopic analysis and Marfey's analysis of acid hydrolysate. Kyanamide exhibited moderate cytotoxicity against HeLa S3 cells. 1 also exhibited potent protease inhibitory activity against elastase and chymotrypsin with IC50 values of 0.13 nM and 1.1 μM.
Ozaki, Kaori,Iwasaki, Arihiro,Suenaga, Kiyotake,Teruya, Toshiaki
p. 3382 - 3386
(2019/05/15)

Induction of cryptic metabolites of the endophytic fungus: Trichocladium sp. through OSMAC and co-cultivation
The endophytic fungus Trichocladium sp. isolated from roots of Houttuynia cordata was cultured on solid rice medium, yielding a new amidepsine derivative (1) and a new reduced spiro azaphilone derivative (3) together with eight known compounds (4-11). Co-cultivation of Trichocladium sp. with Bacillus subtilis resulted in induction of a further new compound (2) and a 10-fold increase of 11 compared to the axenic fungal culture. Moreover, when the fungus was cultivated on peas instead of rice, a new sesquiterpene derivative (13) and two known compounds (12 and 14) were obtained. Addition of 2% tryptophan to rice medium led to the isolation of a new bismacrolactone (15). The structures of the new compounds were elucidated by HRESIMS, 1D and 2D NMR as well as by comparison with the literature. A combination of TDDFT-ECD, TDDFT-SOR, DFT-VCD and DFT-NMR calculations were applied to determine the absolute and relative configurations of 13 and 15. Compounds 7, 11 and 15 exhibited strong cytotoxicity against the L5178Y mouse lymphoma cell line with IC50 values of 0.3, 0.5 and 0.2 μM, respectively.
Tran-Cong, Nam Michael,Mándi, Attila,Kurtán, Tibor,Müller, Werner E.G.,Kalscheuer, Rainer,Lin, Wenhan,Liu, Zhen,Proksch, Peter
p. 27279 - 27288
(2019/09/12)

Isolation and Total Synthesis of Mabuniamide, a Lipopeptide from an Okeania sp. Marine Cyanobacterium
The bioassay-guided fractionation of an Okeania sp. marine cyanobacterium collected in Okinawa led to the isolation of the lipopeptide mabuniamide (1). The gross structure of 1 was determined by spectroscopic analyses, and its absolute configuration was determined using Marfey's analysis of the acid hydrolysate of 1. The absolute configuration of 1 was confirmed by total synthesis. Mabuniamide (1) stimulated glucose uptake in cultured rat L6 myotubes. In addition, mabuniamide (1) and its stereoisomer (2) exhibited moderate antimalarial activity.
Ozaki, Kaori,Iwasaki, Arihiro,Sezawa, Dai,Fujimura, Haruka,Nozaki, Tomoyoshi,Saito-Nakano, Yumiko,Suenaga, Kiyotake,Teruya, Toshiaki
p. 2907 - 2915
(2019/10/16)

Complex-precipitation using functionalized chiral ionic liquids with L-proline anion and chromatographic analysis for enantioseparation of racemic amino acids
As one kind of functionalized green medium, chiral ionic liquids (CILs) have been widely applied in fields of asymmetric catalysis, enantioseparation, and so on. In this study, four kinds of amino acid–based CILs were synthesized by using trimethylamine, N-methylpyrrolidine, N-methylimidazole, and tropine as cationic nucleus, respectively. Then their specific optical rotation and solubility in common solvents were determined for further resolution application. The effect of different cations in these CILs was explored on the separation of racemic phenylalanine in complex-precipitation way. Moreover, various factors were systematically investigated for their effects on resolution efficiency, including the type of additive copper salts, the molar ratio of Cu (II) to CIL, pH value, the amount of racemic phenylalanine, and temperature. Under the appropriate conditions, L-phenylalanine mainly existed in solid phase and could be separated from its enantiomers in liquid phase. Furthermore, the mechanism of resolution was studied by thermogravimetric analysis, infrared spectrum, and molecular simulation. The resolution system has characteristics of no organic solvent, fast separation speed, simple resolution process, and easy scale-up.
Zang, Huimin,Yao, Shun,Luo, Yingjie,Tang, Dan,Song, Hang
p. 1182 - 1194
(2018/09/12)

Driving Transamination Irreversible by Decomposing Byproduct Α-Ketoglutarate into Ethylene Using Ethylene-Forming Enzyme
The transformations of transaminases have been extensively studied as an approach to the production of chiral amino moieties. However, the low equilibrium conversion of the reaction is a critical disadvantage to transaminase application, and a strategy for shifting the reaction equilibrium is essential. Herein, we have developed a novel method to effectively prevent the reversibility of transamination by fully decomposing byproduct α-ketoglutarate into ethylene and carbon dioxide in situ using ethylene-forming enzyme (EFE). Two transaminases and one EFE were expressed in E. coli and purified to be used in the cascade reaction. After optimal reaction conditions were determined based on the enzymatic properties, a cascade reaction coupling transaminase with EFE was conducted and showed high efficiency in the synthesis of l-phosphinothricin. Finally, using this approach with only an equivalent amount of amino donor l-glutamate increased the conversions of various keto acids from 99%. This strategy shows great potential for transamination using glutamate as the amino donor.
Meng, Li-Jun,Liu, Ya-Yun,Zhou, Hai-Sheng,Yin, Xin-Jian,Wu, Jian-Ping,Wu, Mian-Bin,Xu, Gang,Yang, Li-Rong
p. 3309 - 3314
(2018/10/02)

Structural Diversity and Anticancer Activity of Marine-Derived Elastase Inhibitors: Key Features and Mechanisms Mediating the Antimetastatic Effects in Invasive Breast Cancer
Three new 3-amino-6-hydroxy-2-piperidone (Ahp)-containing cyclic depsipeptides, named loggerpeptins A–C (1–3), along with molassamide (4), were discovered from a marine cyanobacterium, extending the structural diversity of this prevalent scaffold of cyanobacterial serine protease inhibitors. Molassamide, which contains a 2-amino-butenoic (Abu) unit in the cyclic core, was the most potent and selective analogue against human neutrophil elastase (HNE). Given the growing evidence supporting the role of HNE in breast cancer progression and metastasis, we assessed the cellular effects of compounds 3 and 4 in the context of targeting invasive breast cancer. Both compounds inhibited cleavage of the elastase substrate CD40 in biochemical assays; however, only 4 exhibited significant cellular activity. As CD40 and other receptor proteolytic processing culminates in NFκB activation, we assessed the effects of 4 on the expression of target genes, including ICAM-1. ICAM-1 is also a direct target of elastase and, in our studies, compound 4 attenuated both elastase-induced ICAM-1 gene expression and ICAM-1 proteolytic processing by elastase, revealing a potential dual effect on migration through modulation of gene expression and proteolytic processing. Molassamide also specifically inhibited the elastase-mediated migration of highly invasive triple-negative breast cancer cells.
Al-Awadhi, Fatma H.,Paul, Valerie J.,Luesch, Hendrik
p. 815 - 825
(2018/03/27)

Kakeromamide A, a new cyclic pentapeptide inducing astrocyte differentiation isolated from the marine cyanobacterium Moorea bouillonii
Kakeromamide A (1), a new cyclic pentapeptide encompassing a thiazole ring moiety and a β-amino acid, was isolated from the marine cyanobacterium Moorea bouillonii. Its structure was elucidated by the spectral analysis and the modified Marfey's method. Compound 1 induced differentiation of neural stem cells into astrocytes at the concentration of 10 μM.
Nakamura, Fumiaki,Maejima, Hiroshi,Kawamura, Midori,Arai, Daisuke,Okino, Tatsufumi,Zhao, Meng,Ye, Tao,Lee, Jungyeol,Chang, Young-Tae,Fusetani, Nobuhiro,Nakao, Yoichi
supporting information
p. 2206 - 2209
(2018/05/25)

Izenamides A and B, Statine-Containing Depsipeptides, and an Analogue from a Marine Cyanobacterium
Izenamides A, B, and C (1-3), new linear depsipeptides, were isolated from a taxonomically distinct marine cyanobacterium. Izenamides A and B contain a statine moiety [(3S,4S)-4-amino-3-hydroxy-6-methylheptanoic acid] and inhibited the activity of cathepsin D, an aspartic peptidase. Meanwhile, izenamides did not show growth-inhibitory activity against HeLa, HL60, or MCF-7 cells at up to 10 μM.
Kanamori, Yuki,Iwasaki, Arihiro,Sumimoto, Shimpei,Matsubara, Teruhiko,Sato, Toshinori,Suenaga, Kiyotake
supporting information
p. 1673 - 1681
(2018/08/04)

Natalenamides A–C, cyclic tripeptides from the termite-associated Actinomadura sp. RB99
In recent years, investigations into the biochemistry of insect-associated bacteria have increased. When combined with analytical dereplication processes, these studies provide a powerful strategy to identify structurally and/or biologically novel compounds. Non-ribosomally synthesized cyclic peptides have a broad bioactivity spectrum with high medicinal potential. Here, we report the discovery of three new cyclic tripeptides: natalenamides A–C (compounds 1–3). These compounds were identified from the culture broth of the fungus-growing termite-associated Actinomadura sp. RB99 using a liquid chromatography (LC)/ultraviolet (UV)/mass spectrometry (MS)-based dereplication method. Chemical structures of the new compounds (1–3) were established by analysis of comprehensive spectroscopic methods, including one-dimensional (1H and13C) and two-dimensional (1H-1H-COSY, HSQC, HMBC) nuclear magnetic resonance spectroscopy (NMR), together with high-resolution electrospray ionization mass spectrometry (HR-ESIMS) data. The absolute configurations of the new compounds were elucidated using Marfey’s analysis. Through several bioactivity tests for the tripeptides, we found that compound 3 exhibited significant inhibitory effects on 3-isobutyl-1-methylxanthine (IBMX)-induced melanin production. The effect of compound 3 was similar to that of kojic acid, a compound extensively used as a cosmetic material with a skin-whitening effect.
Lee, Seoung Rak,Lee, Dahae,Yu, Jae Sik,Benndorf, René,Lee, Sullim,Lee, Dong-Soo,Huh, Jungmoo,Wilhelm de Beer,Kim, Yong Ho,Beemelmanns, Christine,Kang, Ki Sung,Kim, Ki Hyun
(2018/11/24)

Discovery of new A- and B-type laxaphycins with synergistic anticancer activity
Two new cyclic lipopeptides termed laxaphycins B4 (1) and A2 (2) were discovered from a collection of the marine cyanobacterium Hormothamnion enteromorphoides, along with the known compound laxaphycin A. The planar structures were solved based on a combined interpretation of 1D and 2D NMR data and mass spectral data. The absolute configurations of the subunits were determined by chiral LC-MS analysis of the hydrolysates, advanced Marfey's analysis and 1D and 2D ROESY experiments. Consistent with similar findings on other laxaphycin A- and B-type peptides, laxaphycin B4 (1) showed antiproliferative effects against human colon cancer HCT116 cells with IC50 of 1.7 μM, while laxaphycins A and A2 (2) exhibited weak activities. The two major compounds isolated from the sample, laxaphycins A and B4, were shown to act synergistically to inhibit the growth of HCT116 colorectal cancer cells.
Cai, Weijing,Matthew, Susan,Chen, Qi-Yin,Paul, Valerie J.,Luesch, Hendrik
p. 2310 - 2319
(2018/04/02)

Chromatographic Resolution of α-Amino Acids by (R)-(3,3'-Halogen Substituted-1,1'-binaphthyl)-20-crown-6 Stationary Phase in HPLC
Three new chiral stationary phases (CSPs) for high-performance liquid chromatography were prepared from R-(3,3'-halogen substituted-1,1'-binaphthyl)-20-crown-6 (halogen = Cl, Br and I). The experimental results showed that R-(3,3'-dibromo-1,1'-binaphthyl)-20-crown-6 (CSP-1) possesses more prominent enantioselectivity than the two other halogen-substituted crown ether derivatives. All twenty-one α-amino acids have different degrees of separation on R-(3,3'-dibromo-1,1'-binaphthyl)-20-crown-6-based CSP-1 at room temperature. The enantioselectivity of CSP-1 is also better than those of some commercial R-(1,1'-binaphthyl)-20-crown-6 derivatives. Both the separation factors (α) and the resolution (Rs) are better than those of commercial crown ether-based CSPs [CROWNPAK CR(+) from Daicel] under the same conditions for asparagine, threonine, proline, arginine, serine, histidine and valine, which cannot be separated by commercial CR(+). This study proves the commercial usefulness of the R-(3,3'-dibromo-1,1'-binaphthyl)-20-crown-6 chiral stationary phase.
Wu, Peng,Wu, Yuping,Zhang, Junhui,Lu, Zhenyu,Zhang, Mei,Chen, Xuexian,Yuan, Liming
supporting information
p. 1037 - 1042
(2017/07/25)

The optical activity of the valine compound and its production method
The invention relates to an optically active valine compound and a production method thereof. The optically active valine compound is composed of 1 mole of L-valine and 1 mole of N-benzoyl-L-alanine. The production method comprises the steps of reacting the N-benzoyl-L-alanine selectively with L-valine in the presence of D-valine, other amino acids, impurities generated in the DL-valine synthesis process and a crude product L-valine obtained by hydrolyzing or fermenting proteins, thereby forming a novel crystal compound. The optically active L-valine and N-benzoyl-L-alanine can be taken as intermediates for optically decomposing DL-valine and purifying L-valine.
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Paragraph 0068; 0069; 0070

(2017/04/21)

Biseokeaniamides A, B, and C, Sterol O-Acyltransferase Inhibitors from an Okeania sp. Marine Cyanobacterium
Biseokeaniamides A, B, and C (1-3), structurally novel sterol O-acyltransferase (SOAT) inhibitors, were isolated from an Okeania sp. marine cyanobacterium. Their structures were elucidated by spectroscopic analyses and degradation reactions. Biseokeaniamide B (2) exhibited moderate cytotoxicity against human HeLa cancer cells, and compounds 1-3 inhibited both SOAT1 and SOAT2, not only at an enzyme level but also at a cellular level. Biseokeaniamides (1-3) are the first linear lipopeptides that have been shown to exhibit SOAT-inhibitory activity.
Iwasaki, Arihiro,Tadenuma, Takato,Sumimoto, Shimpei,Ohshiro, Taichi,Ozaki, Kaori,Kobayashi, Keisuke,Teruya, Toshiaki,Tomoda, Hiroshi,Suenaga, Kiyotake
p. 1161 - 1166
(2017/05/05)

Nodupetide, a potent insecticide and antimicrobial from Nodulisporium sp. associated with Riptortus pedestris
Nodupetide (1), a new cyclodepsipeptide unique in its incorporation of a 3-hydroxy-4-methylhexanoic acid (HMHA) derived motif, was discovered from Nodulisporium sp. IFB-A163, a fungus residing in the insect (Riptortus pedestris) gut. The nodupetide structure was elucidated by its MS/MS and 2D NMR spectra, and its absolute configuration by the X-ray crystallography and modified Marfey's method. Nodupetide is insecticidal against rice brown planthopper (Nilaparvata lugens) with an LD50value of 70?ng/larva, and inhibitory towards the drug-resistant human pathogenic bacterium Pseudomonas aeruginosa with its MIC value (5.0?μM) comparable to that (3.2?μM) of ciprofloxacin, a prescribed antibacterial agent co-assayed equally.
Wu, Hui Min,Lin, Li Ping,Xu, Qin Lan,Han, Wen Bo,Zhang, Song,Liu, Ze Wen,Mei, Ya Ning,Yao, Zhu Jun,Tan, Ren Xiang
supporting information
p. 663 - 665
(2017/01/25)

Octaminomycins A and B, cyclic octadepsipeptides active against Plasmodium falciparum
Two new cyclic octadepsipeptides, octaminomycins A (1) and B (2), were isolated from a microbial metabolite fraction library of Streptomyces sp. RK85-270 based on Natural Products Plot screening. Their structures were elucidated on the basis of HRESIMS, 1D and 2D NMR spectroscopic data, and MS/MS experiments for sequence analysis. The absolute configurations of the constituent amino acid residues were determined by a combination of single-crystal X-ray diffraction and Marfey's methodology. Notably, octaminomycins A (1) and B (2) showed good in vitro antiplasmodial activity against chloroquine-sensitive as well as chloroquine-resistant strains with no cytotoxicity up to 30 μM. (Chemical Equation Presented).
Jang, Jun-Pil,Nogawa, Toshihiko,Futamura, Yushi,Shimizu, Takeshi,Hashizume, Daisuke,Takahashi, Shunji,Jang, Jae-Hyuk,Ahn, Jong Seog,Osada, Hiroyuki
p. 134 - 140
(2017/02/05)

Identification of Cyclic Depsipeptides and Their Dedicated Synthetase from Hapsidospora irregularis
Seven cyclic depsipeptides were isolated from Hapsidospora irregularis and structurally characterized as the calcium channel blocker leualacin and six new analogues based on the NMR and HRESIMS data. These new compounds were named leualacins B-G. The absolute configurations of the amino acids and 2-hydroxyisocaproic acids were determined by recording the optical rotation values. Biological studies showed that calcium influx elicited by leualacin F in primary human lobar bronchial epithelial cells involves the TRPA1 channel. Through genome sequencing and targeted gene disruption, a noniterative nonribosomal peptide synthetase was found to be involved in the biosynthesis of leualacin. A comparison of the structures of leualacin and its analogues indicated that the A2 and A4 domains of the leualacin synthetase are substrate specific, while A1, A3, and A5 can accept alternative precursors to yield new molecules.
Zhang, Shuwei,Qiu, Yixing,Kakule, Thomas B.,Lu, Zhenyu,Xu, Fuchao,Lamb, John G.,Reilly, Christopher A.,Zheng, Yong,Sham, Shing Wo Simon,Wang, Wei,Xuan, Lijiang,Schmidt, Eric W.,Zhan, Jixun
p. 363 - 370
(2017/03/08)

Development of a multi-enzymatic desymmetrization and its application for the biosynthesis of L-norvaline from DL-norvaline
Perindopril is an effective antihypertensive drug in strong demand used to treat hypertension. L-norvaline is a vital intermediate of Perindopril production mainly produced by chemical synthesis with low purity. We developed an environmentally friendly method to produce L-norvaline with high purity based on a desymmetrization process. D-Norvaline was oxidized to the corresponding keto acid by D-amino acid oxidase from the substrate DL-norvaline. Asymmetric hydrogenation of the keto acid to L-norvaline was carried out by leucine dehydrogenase with concomitant oxidation of NADH to NAD+. A NADH regeneration system was introduced by overexpressing a formate dehydrogenase. The unwanted H2O2by-product generated during D-norvaline oxidation was removed by adding catalase. A total of 54.09?g/L of L-norvaline was achieved, with an enantiomeric excess over 99% under optimal conditions, with a 96.7% conversion rate. Our desymmetrization method provides an environmental friendly strategy for the production of enantiomerically pure L-norvaline in the pharmaceutical industry.
Qi, Yunlong,Yang, Taowei,Zhou, Junping,Zheng, Junxian,Xu, Meijuan,Zhang, Xian,Rao, Zhiming,Yang, Shang-Tian
p. 104 - 109
(2017/03/23)

Odobromoamide, a terminal alkynyl bromide-containing cyclodepsipeptide from the marine cyanobacterium okeania sp.
The bioassay-guided fractionation of the Okinawan marine cyanobacterium Okeania sp. led to the isolation of the novel cyclodepsipeptide odobromoamide (1). The gross structure of 1 was determined by spectroscopic analyses, and its absolute stereochemistry was determined using a variety of different methods, including chemical derivatization and degradation followed by HPLC analysis. In addition, odobromoamide (1) exhibited broad-spectrum cytotoxicity against a human cancer cell line panel.
Sueyoshi, Kosuke,Kudo, Takafumi,Yamano, Aki,Sumimoto, Shimpei,Iwasaki, Arihiro,Suenaga, Kiyotake,Teruya, Toshiaki
p. 436 - 440
(2017/06/14)

Dudawalamides A-D, Antiparasitic Cyclic Depsipeptides from the Marine Cyanobacterium Moorea producens
A family of 2,2-dimethyl-3-hydroxy-7-octynoic acid (Dhoya)-containing cyclic depsipeptides, named dudawalamides A-D (1-4), was isolated from a Papua New Guinean field collection of the cyanobacterium Moorea producens using bioassay-guided and spectroscopic approaches. The planar structures of dudawalamides A-D were determined by a combination of 1D and 2D NMR experiments and MS analysis, whereas the absolute configurations were determined by X-ray crystallography, modified Marfey's analysis, chiral-phase GCMS, and chiral-phase HPLC. Dudawalamides A-D possess a broad spectrum of antiparasitic activity with minimal mammalian cell cytotoxicity. Comparative analysis of the Dhoya-containing class of lipopeptides reveals intriguing structure-activity relationship features of these NRPS-PKS-derived metabolites and their derivatives.
Almaliti, Jehad,Malloy, Karla L.,Glukhov, Evgenia,Spadafora, Carmenza,Gutiérrez, Marcelino,Gerwick, William H.
p. 1827 - 1836
(2017/06/28)

Stylissamide I, a new cyclic heptapeptide from an okinawan marine sponge Stylissa sp.
A new cyclic heptapeptide, stylissamide I (1), was isolated from an Okinawan marine sponge Stylissa sp. The structure of stylissamide I (1) was elucidated to be cyclo-(L-Tyr1-L-Tyr2-L-Tyr3-L-Pro1-L-Pro2-L-Val-L-Pro3) by extensive spectral analyses and Marfey's method. Stylissamide I (1) showed antifungal activity against Aspergillus Niger.
Kubota, Takaaki,Nakamura, Kenta,Kurimoto, Shin-Ichiro,Sakai, Kanae,Fromont, Jane,Gonoi, Tohru,Kobayashi, Jun'ichi
p. 799 - 806
(2017/07/28)

Anti-Cryptococcus Phenalenones and Cyclic Tetrapeptides from Auxarthron pseudauxarthron
Auxarthrones A-E (1-5), five new phenalenones, and two new naturally occurring cyclic tetrapeptides, auxarthrides A (7) and B (8), were obtained from three different solvent extracts of cultures of the coprophilous fungus Auxarthron pseudauxarthron. Auxarthrones C (3) and E (5) possess an unusual 7a,8-dihydrocyclopenta[a]phenalene-7,9-dione ring system that has not been previously observed in natural products. Formation of 1-5 was found to be dependent on the solvent used for culture extraction. The structures of these new compounds were elucidated primarily by analysis of NMR and MS data. Auxarthrone A (1) was obtained as a mixture of chromatographically inseparable racemic diastereomers (1a and 1b) that cocrystallized, enabling confirmation of their structures by X-ray crystallography. The absolute configurations of 7 and 8 were assigned by analysis of their acid hydrolysates using Marfey's method. Compound 1 displayed moderate antifungal activity against Cryptococcus neoformans and Candida albicans, but did not affect human cancer cell lines.
Li, Yan,Yue, Qun,Jayanetti, Dinith R.,Swenson, Dale C.,Bartholomeusz, Geoffrey A.,An, Zhiqiang,Gloer, James B.,Bills, Gerald F.
supporting information
p. 2101 - 2109
(2017/08/04)

Purification, structural characterization and bioactivity evaluation of a novel proteoglycan produced by Corbicula fluminea
A novel proteoglycan, named CFPS-11, was isolated from Corbicula fluminea, which is a food source of freshwater bivalve mollusk. CFPS-11 had an average molecular weight of 807.7 kDa and consisted of D-glucose and D-glucosamine in a molar ratio of 12.2:1.0. The protein moiety (～5%) of CFPS-11 was covalently bonded to the polysaccharide chain in O-linkage type through both serine and thereonine residues. The polysaccharide chain of CFPS-11 was composed of (1 → 4)-α-D-glucopyranosyl and (1 → 3,6)-α-D-glucopyranosyl residues, which branched at O-6. The branch chain consisted of (1 →)-α-D-glucopyranosyl and (1 →)-α-D-N-acetylglucosamine residues. CFPS-11 exhibited significant antioxidant activity in a dose-dependent manner and remarkable inhibition activities against α-amylase and α-glucosidase by in vitro assays. These findings indicated that the CFPS-11 from C. fluminea has the potential for development as a health food ingredient.
Yan, Jing-Kun,Wang, Yao-Yao,Qiu, Wen-Yi,Wu, Li-Xia,Ding, Zhi-Chao,Cai, Wu-Dan
p. 11 - 18
(2017/08/29)

Derivative of hyaluronic acid modified with amino-carboxylic acid
The present invention provides a hyaluronic acid derivative comprising disaccharide units of Formula (I), and a hyaluronic acid derivative/drug conjugate wherein one or more drugs are conjugated to the hyaluronic acid derivative.
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(2016/02/12)

Pembamide, a N-methylated linear peptide from a sponge Cribrochalina sp.
A new highly N-methylated linear peptide, pembamide (1), has been isolated from the marine sponge Cribrochalina sp. (family Niphatidae) collected off the coast of Pemba (Tanzania). The planar structure of 1 was assigned on the basis of extensive 1D and 2D NMR spectroscopy and mass spectrometry. The absolute configuration of the amino acid residues in 1 was determined by application of the Advanced Marfey's method. Compound 1 displayed significant cytotoxicity against three human tumor cell lines with GI50values in the micromolar range.
Urda, Carlos,Pérez, Marta,Rodríguez, Jaime,Jiménez, Carlos,Cuevas, Carmen,Fernández, Rogelio
supporting information
p. 3239 - 3242
(2016/07/11)