scholarly journals Amycolatomycins A and B, Cyclic Hexapeptides Isolated from an Amycolatopsis sp. 195334CR

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 261
Author(s):  
Gian Primahana ◽  
Chandra Risdian ◽  
Tjandrawati Mozef ◽  
Joachim Wink ◽  
Frank Surup ◽  
...  

The rare actinobacterium Amycolatopsis sp. strain 195334CR was found to produce previously undescribed cyclic hexapeptides, which we named amycolatomycin A and B (1 and 2). Their planar structures were determined by high-resolution mass spectrometry as well as extensive 1D and 2D NMR spectroscopy, while the absolute stereochemistry of its amino acids were determined by Marfey’s method. Moreover, 1 and 2 differ by the incorporation of l-Ile and l-allo-Ile, respectively, whose FDVA (Nα-(2,4-Dinitro-5-fluorphenyl)-L-valinamide) derivatives were separated on a C4 column. Their hallmark in common is a unique 2,6-dichloro-tryptophan amino acid unit. Amycolatomycin A (1) exhibited weak activity against Bacillus subtilis DSM 10 (minimum inhibitory concentration (MIC) = 33.4 µg/mL).

Marine Drugs ◽  
2022 ◽  
Vol 20 (1) ◽  
pp. 51
Author(s):  
Senhua Chen ◽  
Heng Guo ◽  
Minghua Jiang ◽  
Qilin Wu ◽  
Jing Li ◽  
...  

Seven new xanthones, diaporthones A−G (1−7), together with 13 known analogues, including five mono- (8−14) and six dimeric xanthones (15−20), were obtained from the ascidian-derived fungus Diaporthe sp. SYSU-MS4722. Their planar structures were established by extensive spectroscopic analyses, including 1D and 2D NMR and high-resolution mass spectrometry (HR-ESIMS). The absolute configurations of 1−7 were clearly identified by X-ray crystallographic analysis and calculation of the ECD Spectra. Compounds 15−20 showed significant anti-inflammatory activity with IC50 values between 6.3 and 8.0 μM. In addition, dimeric xanthones (15−20) showed selective cytotoxicity against T98G cell lines with IC50 values ranging from 19.5 to 78.0 μM.


2013 ◽  
Vol 8 (9) ◽  
pp. 1934578X1300800
Author(s):  
Sumbul Azmat ◽  
Rehana Ifzal ◽  
Faryal Vali Mohammad ◽  
Viqar Uddin Ahmad ◽  
Aqib Zahoor

A new glucuronolactone glycoside, phoenixoside B (1), has been isolated from the n-butanol soluble fraction of seeds of Phoenix dactylifera. The structure was characterized as 1-(1-ethyl-β-D-glucosyl)-4,5-diethyl-[α-D-glucofuranourono-6,3-lactone] on the basis of 1D and 2D-NMR spectroscopy and high-resolution mass spectrometry.


2007 ◽  
Vol 62 (1) ◽  
pp. 132-134 ◽  
Author(s):  
Christian Zidorn ◽  
Ernst-Peter Ellmerer ◽  
Werner Heller ◽  
Richard Greil ◽  
Manuela Guggenberger ◽  
...  

The new sesquiterpenoid 8-deoxy-15-(3′-hydroxy-2′-methyl-propanoyl)-lactucin 3′-sulfate (1) was isolated from the methanolic extract of roots of Reichardia gaditana L. The compound was isolated by silica gel column chromatography (CC) and repeated Sephadex LH-20 CC. Structure elucidation was accomplished by high-resolution mass spectrometry and by 1D- and 2D-NMR spectroscopy. The chemosystematic significance of the new compound is discussed in the context of sesquiterpenoids from other members of the Lactuceae tribe of the Asteraceae family.


2012 ◽  
Vol 7 (1) ◽  
pp. 1934578X1200700
Author(s):  
Sumbul Azmat ◽  
Aqib Zahoor ◽  
Rehana Ifzal ◽  
Viqar Uddin Ahmad ◽  
Faryal Vali Mohammed

A new megastigmane glycoside, phoenixoside A (1), has been isolated from the n-butanol - soluble fraction of seeds of Phoenix dactylifera. The structure was characterized as (6S,7Z,9R)-hydroxy-3-oxo-ionol-9- O-β-D-glucopyranosyl-(1″→6′)-β-D–glucopyranoside on the basis of 1D and 2D NMR spectroscopy, high-resolution mass spectrometry, and CD spectroscopy.


Marine Drugs ◽  
2021 ◽  
Vol 19 (10) ◽  
pp. 565
Author(s):  
Ye Yuan ◽  
Te Li ◽  
Tingting Wang ◽  
C. Benjamin Naman ◽  
Jing Ye ◽  
...  

LC-MS/MS-based molecular networking facilitated the targeted isolation of a new cyclic hexadepsipeptide, cymodepsipeptide (1), and two known analogues, RF–2691A (2) and RF–2691B (3), from the fungus Cymostachys sp. NBUF082 that was derived from a mesophotic zone Aaptos sponge collected near Apo Island. The constitution and configuration of 1 was elucidated through 1D and 2D NMR-spectroscopy, high resolution mass-spectrometry, and chemical degradations including Marfey’s analysis and chiral HPLC. It was observed that 1 was moderately cytotoxic against CCRF-CEM human acute lymphocytic leukemia cells in vitro with the IC50 value of 9.2 ± 1.1 μM.


2019 ◽  
Vol 41 (4) ◽  
pp. 695-695
Author(s):  
Saima Khan Saima Khan ◽  
Muhammad Imran Tousif Muhammad Imran Tousif ◽  
Naheed Raiz Naheed Raiz ◽  
Mamona Nazir Mamona Nazir ◽  
Mahreen Mukhtar Mahreen Mukhtar ◽  
...  

Silica gel column chromatography of the ethyl acetate fraction of methanol extract of Vincetoxicum stocksii resulted in the separation of three new rarely occurring natural products; [4-(4-(methoxycarbonyl)benzyl)phenyl] carbamic acid (1), bis[di-p-phenylmethane]ethyl carbamate (2), methyl 2-hydroxy-3-(2-hydroxy-5-(3-methylbut-2-enyl)phenyl)-2-(4-hydroxyphenyl) propanoate, stocksiloate(3), along with five known compounds; 1-(4-hydroxy-3-methoxyphenyl)-1,2,3,-propanetriol (4), feruloyl-6-O-β-D-glucopyranoside (5), 4-hydroxy-3,5-dimethoxybenzoic acid (6), apocynin (7) and vincetomine (8). The structures of compounds 1 and 2 were established with help of 1D, 2D-NMR techniques and high resolution mass spectrometry, whereas, compound 3 could only be characterized tentatively by 1D, 2D-NMR techniques. Compounds 1 is new compound while 2 is synthetically known but never been reported from natural source. The known compounds were identified due to 1D NMR analysis and in comparison with the literature values. Compounds 1-3 were found inactive in an anti-urease assay.


2022 ◽  
Vol 9 ◽  
Author(s):  
Jun Tang ◽  
Xueshuang Huang ◽  
Ming-Hang Cao ◽  
Zhiyan Wang ◽  
Zhiyin Yu ◽  
...  

During a screening for antifungal secondary metabolites, six new mono-/bis-alkenoic acid derivatives (2–7) and one known alkenoic acid derivative (1) were isolated from an endophytic fungi Scopulariopsis candelabrum. Their chemical structures were identified by 1H-NMR, 13C-NMR, 2D NMR, and high-resolution mass spectrometry, as well as comparisons with previously reported literatures. Among them, fusariumesters C‒F (2–5) are bis-alkenoic acid derivatives dimerized by an ester bond, while acetylfusaridioic acid A (6) and fusaridioic acid D (7) are alkenoic acid monomers. All the isolates were submitted to an antifungal assay against Candida albicans and the corn pathogen Exserohilum turcicum using the filter paper agar diffusion method. As a result, only compound 1 decorating with β-lactone ring turned out to be active against these two tested fungi. The broth microdilution assay against Candida albicans showed the minimum inhibitory concentration (MIC) value of 1 to be 20 μg/ml, while the minimum inhibitory concentration value of the positive control (naystatin) was 10 μg/ml. And the half maximal inhibitory concentration (IC50) value (21.23 μg/ml) of 1 against Exserohilum turcicum was determined by analyzing its inhibition effect on the mycelial growth, using cycloheximide (IC50 = 46.70 μg/ml) as the positive control.


Molbank ◽  
10.3390/m1112 ◽  
2020 ◽  
Vol 2020 (1) ◽  
pp. M1112
Author(s):  
Ricson P. Hutagaol ◽  
Desi Harneti ◽  
Ace T. Hidayat ◽  
Nurlelasari Nurlelasari ◽  
Rani Maharani ◽  
...  

A new propylcholesterol-type steroid, namely (22E,24S)-24-propylcholest-5en-3α-acetate (1), has been isolated from the stembark of Aglaia angustifolia (Miq.). The structure of 1 was determined on the basis of spectroscopic data including 1D- and 2D-NMR as well as high resolution mass spectroscopy analysis. Compound 1 showed weak activity against the MCF-7 breast cancer cell line.


1968 ◽  
Vol 21 (8) ◽  
pp. 2095 ◽  
Author(s):  
JB Mc Alpine ◽  
NV Riggs ◽  
PG Gordon

The α,α?-diaryl-β,β-dimethyltetrahydrofurenoid lignan, calopiptin, from Piptocalyx moorei has been converted by demethylenation and methylation into veraguensin, now also isolated from Trimenia papuana (both species, family Trimeniaceae). Ozonolysis yields (-)-2,3-dimethylsuocinic acid which establishes the absolute trans configuration of the methyl groups. The benzylic proton giving a signal at low field from the other in the p.m.r, spectrum is assigned as trans to the adjacent methyl group by shielding and spin-decoupling arguments. The signal moves to even lower field on nitration of one of the aryl groups, identified as 3,4-dimethoxyphenyl by competitive nitration experiments and high-resolution mass spectrometry. Calopiptin is 2R-(3,4-dimethoxyphenyl)-3S,4S-dimethyl-5S-(3,4-methylenedioxyphenyl)tetrahydrofuran.


1996 ◽  
Vol 74 (2) ◽  
pp. 165-172 ◽  
Author(s):  
Youla S. Tsantrizos ◽  
Sotiria Pischos ◽  
Françoise Sauriol ◽  
Paul Widden

Three antibiotic peptides, LP237-F8 (1), F5 (2), and F7 (3), were isolated from the liquid culture of the fungus Tolypocladium geodes. Chemical shift assignments of the 1H and 13C NMR resonances and sequencing of these metabolites were achieved by extensive high-field 2D NMR spectroscopy. The N-terminal of peptides 1 and 2 is protected with an octanoyl (Oc) fatty acid unit, whereas that of peptide 3 is protected with a decanoyl (Dec) unit. The C-terminal of all three peptides is protected with the amino alcohol leucinol (Lol). All three metabolites contain the common amino acids Ala, Phe or Tyr, Pro, and Gln, as well as the unusual amino acid α-aminoisobutyric acid (Aib). In addition, peptides 1 and 2 contain the amino acid α-amino-α-ethyl-n-pentanoic acid (α-ethylnorvaline, EtNor), which has not been previously reported as a constituent of a natural product. Metabolites 1, 2, and 3 are new members of the class of natural products known as peptaibols. Key words: Tolypocladium geodes, peptaibols, leucinol, α-amino-α-ethyl-n-pentanoic acid.


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