scholarly journals Natalenamides A–C, Cyclic Tripeptides from the Termite-Associated Actinomadura sp. RB99

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 3003 ◽  
Author(s):  
Seoung Rak Lee ◽  
Dahae Lee ◽  
Jae Sik Yu ◽  
René Benndorf ◽  
Sullim Lee ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cyclic Peptides ◽  
Culture Broth ◽  
Resonance Spectroscopy ◽  
Ionization Mass ◽  
Inhibitory Effects ◽  
Associated Bacteria ◽  
Chemical Structures ◽  
New Compounds ◽  
Powerful Strategy

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 and 13C) 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.

scholarly journals Three New Constituents From the Parasitic Plant Balanophora laxiflora

2019 ◽  
Vol 14 (5) ◽  
pp. 1934578X1984995
Author(s):  
Bui Huu Tai ◽  
Nguyen Thi Hong Anh ◽  
Nguyen Thi Cuc ◽  
Pham Hai Yen ◽  
Nguyen Xuan Nhiem ◽  
...  
Keyword(s):  
Parasitic Plant ◽  
Resonance Spectroscopy ◽  
No Production ◽  
Ionization Mass ◽  
Chemical Structures ◽  
Raw264.7 Macrophages ◽  
Extensive Analysis ◽  
Whole Plant ◽  
New Compounds ◽  
Modified Mosher’S Method

Three new constituents (1-3) were isolated from the whole plant of Balanophora laxiflora. Their chemical structures were elucidated by extensive analysis of high-resolution electrospray ionization mass spectrometry and nuclear magnetic resonance spectroscopy. Absolute configurations of new compounds were determined by circular dichroism spectra and modified Mosher’s method. The isolated compounds weakly inhibited on both NO production and COX-2 mRNA expression in RAW264.7 macrophages.

scholarly journals Isolation and Purification of Bioactive Compounds from the Stem Bark of Jatropha podagrica

Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 889 ◽  
Author(s):  
Truong Minh ◽  
Tran Xuan ◽  
Hoang-Dung Tran ◽  
Truong Van ◽  
Yusuf Andriana ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Ethyl Acetate ◽  
Gallic Acid ◽  
Bioactive Compounds ◽  
Stem Bark ◽  
Ionization Mass ◽  
Methyl Gallate ◽  
Antioxidant Power ◽  
Isolation And Purification ◽  
Chemical Structures

This paper reports the successive isolation and purification of bioactive compounds from the stem bark of Jatropha podagrica, a widely known medicinal plant. The ethyl acetate extract of the stem bark exhibited the strongest antioxidant activity assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, and ferric reducing antioxidant power (FRAP) assays (IC50 = 46.7, 66.0, and 492.6, respectively). By column chromatography (CC) with elution of hexane and ethyl acetate at 8:2, 7:3, and 6:4 ratios, the isolation of this active extract yielded five fractions (C1–C5). Chemical structures of the constituents included in C1–C5 were elucidated by gas chromatography-mass spectrometry (GC-MS), electrospray ionization-mass spectrometry (ESI-MS), and nuclear magnetic resonance (NMR) and resolved as methyl gallate (C1, C2, C3, C4), gallic acid (C1, C2), fraxetin (C2, C3, C4, C5), and tomentin (C3). Mixture C2 (IC50 DPPH and ABTS = 2.5 µg/mL) and C3 (IC50 FRAP = 381 µg/mL) showed the highest antioxidant properties. Among the isolated fractions, C4 was the most potential agent in growth inhibition of six bacterial strains including Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Listeria monocytogenes, Bacillus subtilis, and Proteus mirabilis (MIC = 5, 20, 30, 20, 25, and 20 mg/mL, respectively). All identified constituents exerted an inhibitory activity on the growth of Lactuca sativa, of which the mixture C3 performed the maximal inhibition on shoot (IC50 = 49.4 µg/mL) and root (IC50 = 47.1 µg/mL) growth. Findings of this study suggest that gallic acid, methyl gallate, fraxetin, and tomentin isolated from J. podagrica possessed antioxidant, antibacterial, and growth inhibitory potentials.

scholarly journals Guaiane Sesquiterpenes from the Rhizome of Curcuma xanthorrhiza and Their Inhibitory Effects on UVB-induced MMP-1 Expression in Human Keratinocytes

2017 ◽  
Vol 12 (10) ◽  
pp. 1934578X1701201
Author(s):  
Ji-Hae Park ◽  
Mohamed Antar Aziz Mohamed ◽  
Nhan Nguyen Thi ◽  
Kyeong-Hwa Seo ◽  
Ye-Jin Jung ◽  
...  
Keyword(s):  
Mrna Level ◽  
Human Keratinocytes ◽  
Electron Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Aging Effects ◽  
Inhibitory Effects ◽  
Chemical Structures ◽  
Skin Cells ◽  
Curcuma Xanthorrhiza ◽  
First Time

A new guaiane sesquiterpene, (1 R,4 S,5 S,10 R)-10-methyl guaianediol (1), along with five known compounds, 10-methylalismoxide (2), (+)-alismoxide (3), isozedoarondiol (4), zedoarondiol (5), and zedoalactone B (6), were isolated from the rhizomes of Curcuma xanthorrhiza Roxb. Compounds 1-6 were isolated from this plant for the first time. Chemical structures were determined using nuclear magnetic resonance (NMR), electron ionization mass spectrometry (EI/MS), polarimetry, circular dichroism (CD), and infrared spectroscopy (IR). Compounds 3 and 4 decreased MMP-1 expression in UVB-treated human keratinocytes by about 8.9-fold and 7.6-fold at the mRNA level, and by about 9.2-fold and 6.6-fold at the protein level, respectively. Results indicate that the isolated compounds have anti-aging effects by inhibiting MMP-1 expression in skin cells.

scholarly journals A new tetracyclic diterpenoid from the seeds of Euphorbia lathyris

2020 ◽  
Vol 44 (5-6) ◽  
pp. 322-325
Author(s):  
Lie-Feng Ma ◽  
Yue Zhang ◽  
Xuan Zhang ◽  
Meng-Jia Chen ◽  
Zha-Jun Zhan ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
High Resolution ◽  
Spectroscopic Data ◽  
Resonance Spectroscopy ◽  
Ionization Mass ◽  
Two Dimensional ◽  
Detailed Interpretation ◽  
A Minor ◽  
Euphorbia Lathyris

Eupholathone, a minor diterpenoid with an unusual tetracyclic skeleton, was obtained from the seeds of Euphorbia lathyris, along with two known lathyrane diterpenoids, euphorbia factors L2 and L3. The structure of eupholathone was elucidated by detailed interpretation of its spectroscopic data, especially two-dimensional nuclear magnetic resonance spectroscopy and high-resolution electrospray ionization mass spectrometry.

scholarly journals Photocatalytic Degradation of Trifluralin, Clodinafop-Propargyl, and 1,2-Dichloro-4-Nitrobenzene As Determined by Gas Chromatography Coupled with Mass Spectrometry

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Niyaz A. Mir ◽  
A. Khan ◽  
M. Muneer ◽  
S. Vijayalakhsmi
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Photocatalytic Degradation ◽  
Degradation Mechanism ◽  
Gas Chromatography Mass Spectrometry ◽  
Ionization Mass ◽  
Water Medium ◽  
Fragmentation Pattern ◽  
Chemical Structures ◽  
Clodinafop Propargyl

Phototransformation is considered one of the most key factors affecting the fate of pesticides. Therefore, our study focused on photocatalytic degradation of three selected pesticide derivatives: trifluralin (1), clodinafop-propargyl (2), and 1,2-dichloro-4-nitrobenzene (3). The degradation was carried out in acetonitrile/water medium in the presence of titanium dioxide (TiO2) under continuous purging of atmospheric air. The course of degradation was followed by thin-layer chromatography and gas chromatography-mass spectrometry techniques. Electron ionization mass spectrometry was used to identify the degradation species. GC-MS analysis indicates the formation of several intermediate products which have been characterized on the basis of molecular ion, mass fragmentation pattern, and comparison with NIST library. The photocatalytic degradation of pesticides of different chemical structures manifested distinctly different degradation mechanism. The major routes for the degradation of pesticides were found to be (a) dealkylation, dehalogenation, and decarboxylation, (b) hydroxylation, (c) oxidation of side chain, if present, (d) isomerization and cyclization, (e) cleavage of alkoxy bond, and (f) reduction of triple bond to double bond and nitro group to amino.

scholarly journals Saccharobisindole, Neoasterric Methyl Ester, and 7-Chloro-4(1H)-quinolone: Three New Compounds Isolated from the Marine Bacterium Saccharomonospora sp.

Marine Drugs ◽  
2021 ◽  
Vol 20 (1) ◽  
pp. 35
Author(s):  
Sohee Kim ◽  
Tu Cam Le ◽  
Sang-Ah Han ◽  
Prima F. Hillman ◽  
Ahreum Hong ◽  
...  
Keyword(s):  
Methyl Ester ◽  
Marine Bacterium ◽  
High Resolution Mass Spectrometry ◽  
Micrococcus Luteus ◽  
Culture Broth ◽  
Chemical Components ◽  
Inhibition Activity ◽  
Chemical Structures ◽  
New Compounds ◽  
And Staphylococcus Aureus

Analysis of the chemical components from the culture broth of the marine bacterium Saccharomonospora sp. CNQ-490 has yielded three novel compounds: saccharobisindole (1), neoasterric methyl ester (2), and 7-chloro-4(1H)-quinolone (3), in addition to acremonidine E (4), pinselin (5), penicitrinon A (6), and penicitrinon E (7). The chemical structures of the three novel compounds were elucidated by the interpretation of 1D, 2D nuclear magnetic resonance (NMR), and high-resolution mass spectrometry (HRMS) data. Compound 2 generated weak inhibition activity against Bacillus subtilis KCTC2441 and Staphylococcus aureus KCTC1927 at concentrations of 32 μg/mL and 64 μg/mL, respectively, whereas compounds 1 and 3 did not have any observable effects. In addition, compound 2 displayed weak anti-quorum sensing (QS) effects against S. aureus KCTC1927 and Micrococcus luteus SCO560.

scholarly journals Four New Acyclic Diterpenes From Siegesbeckia orientalis

2021 ◽  
Vol 16 (11) ◽  
pp. 1934578X2110561
Author(s):  
Do Thi Trang ◽  
Phan Thi Thanh Huong ◽  
Nguyen Thi Cuc ◽  
Duong Thi Dung ◽  
Bui Thi Thu Trang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
High Resolution ◽  
Xanthine Oxidase ◽  
Ionization Mass ◽  
Oxidative Reaction ◽  
Chemical Structures ◽  
Aerial Parts ◽  
Extensive Analysis ◽  
Siegesbeckia Orientalis

Four new acyclic diterpenes, siegetalises A-D (1-4), were isolated from the aerial parts of Siegesbeckia orientalis. Their chemical structures were elucidated by extensive analysis of high-resolution electrospray ionization mass spectrometry and nuclear magnetic resonance spectral data. The effects of the isolated compounds on the activity of xanthine oxidase were evaluated by the oxidative reaction with xanthine as a substrate. At a concentration of 50 µM, compounds 1-4 exhibited xanthine oxidase inhibitory activity at levels of 13.59% ± 0.51%, 19.64% ± 1.54%, 17.45% ± 1.26%, and 21.36% ± 1.40%, respectively.

scholarly journals Antimicrobial Lavandulylated Flavonoids from a Sponge-Derived Streptomyces sp. G248 in East Vietnam Sea

Marine Drugs ◽  
2019 ◽  
Vol 17 (9) ◽  
pp. 529 ◽  
Author(s):  
Cao ◽  
Trinh ◽  
Mai ◽  
Vu ◽  
Le ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Antimicrobial Activity ◽  
Mycobacterium Tuberculosis ◽  
Spectroscopic Data ◽  
Inhibitory Concentration ◽  
Culture Broth ◽  
Ionization Mass ◽  
Streptomyces Sp ◽  
Mycobacterium Tuberculosis H37rv

Three new lavandulylated flavonoids, (2S,2′’S)-6-lavandulyl-7,4′-dimethoxy-5,2′-dihydroxylflavanone (1), (2S,2′’S)-6-lavandulyl-5,7,2′,4′-tetrahydroxylflavanone (2), and (2′’S)-5′-lavandulyl-2′-methoxy-2,4,4′,6′-tetrahydroxylchalcone (3), along with seven known compounds 4–10 were isolated from culture broth of Streptomyces sp. G248. Their structures were established by spectroscopic data analysis, including 1D and 2D nuclear magnetic resonance (NMR), and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS). The absolute configurations of 1–3 were resolved by comparison of their experimental and calculated electronic circular dichroism spectra. Compounds 1–3 exhibited remarkable antimicrobial activity. Whereas, two known compounds 4 and 5 exhibited inhibitory activity against Mycobacterium tuberculosis H37Rv with minimum inhibitory concentration (MIC) values of 6.0 µg/mL and 11.1 µg/mL, respectively.

scholarly journals A practical synthesis of 3-chloro-2,4-difluoro-5-hydroxybenzoic acid

2020 ◽  
pp. 174751982093225
Author(s):  
Mingguang Zhang ◽  
Zhongbao Bi ◽  
Yunyun Wang ◽  
Yuxun Zhao ◽  
Yang Yang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Ionization Mass ◽  
Hydroxybenzoic Acid ◽  
Reaction Conditions ◽  
Reduction Of No ◽  
Synthetic Strategy ◽  
Practical Synthesis ◽  
Quinolinecarboxylic Acid

A new and practical synthesis of 3-chloro-2,4-difluoro-5-hydroxybenzoic acid, a key intermediate for preparing antimicrobial 3-quinolinecarboxylic acid drugs, is synthesized from 2,4-difluoro-3-chlororobenzoic acid. The protocol involves nitration, esterification, reduction of NO2, diazotization, and hydrolysis with a 70% overall yield. The structures of the synthesized compounds are determined by infrared spectroscopy, nuclear magnetic resonance spectroscopy, and high-resolution electrospray ionization mass spectrometry. The advantages of this developed synthetic strategy include an improved overall yield and readily controllable reaction conditions.

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