scholarly journals Structure and Absolute Configuration of Phenanthro-perylene Quinone Pigments from the Deep-Sea Crinoid Hypalocrinus naresianus

Marine Drugs ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. 445
Author(s):  
Sahithya Phani Babu Vemulapalli ◽  
Juan Carlos Fuentes-Monteverde ◽  
Niels Karschin ◽  
Tatsuo Oji ◽  
Christian Griesinger ◽  
...  
Keyword(s):  
Natural Products ◽  
Dft Calculations ◽  
Absolute Configuration ◽  
13C Nmr ◽  
Deep Sea ◽  
Spectroscopic Analysis ◽  
2D Nmr ◽  
Water Soluble ◽  
Spectroscopy Analysis ◽  
1H And 13C Nmr

Two new water-soluble phenanthroperylene quinones, gymnochrome H (2) and monosulfated gymnochrome A (3), as well as the known compounds gymnochrome A (4) and monosulfated gymnochrome D (5) were isolated from the deep-sea crinoid Hypalocrinus naresianus, which had been collected in the deep sea of Japan. The structures of the compounds were elucidated by spectroscopic analysis including HRMS, 1D 1H and 13C NMR, and 2D NMR. The absolute configuration was determined by ECD spectroscopy, analysis of J-couplings and ROE contacts, and DFT calculations. The configuration of the axial chirality of all isolated phenanthroperylene quinones (2–5) was determined to be (P). For gymnochrome H (2) and monosulfated gymnochrome A (3), a (2′S,2″R) configuration was determined, whereas for monosulfated gymnochrome D (5) a (2′R,2″R), configuration was determined. Acetylated quinones are unusual among natural products from an echinoderm and gymnochrome H (2) together with the recently reported gymnochrome G (1) represent the first isolated acetylated phenanthroperylene quinones.

scholarly journals New Metabolites From the Endophytic Fungus Cercophora samala Associated With Mitragyna inermis

2021 ◽  
Vol 16 (5) ◽  
pp. 1934578X2110132
Author(s):  
Erik Donfack Vouffo ◽  
Clovis Douanla-Meli ◽  
Angelbert Fusi Awantu ◽  
Bruno Ndjakou Lenta ◽  
Sylvère Ngouela ◽  
...  
Keyword(s):  
Natural Products ◽  
Dft Calculations ◽  
Absolute Configuration ◽  
Endophytic Fungus ◽  
Spectroscopic Data ◽  
Spectroscopic Analysis ◽  
The Absolute ◽  
New Metabolites ◽  
Mitragyna Inermis

Two new natural products, mitrafungidione (1) elucidated as prototrop-isomers of ( R-3-acetyl-5-ethyl-4-hydroxy-5 H-furan-2-one, and maristachone F (2a), elucidated as 5-(1-hydroxyethyl)-4-(hydroxymethyl)-3-methoxy-2-methylphenol, together with 5 known compounds have been isolated from the solid cultures of an endophytic fungus associated with Mitragyna inermis (Rubiaceae) and identified as Cercophora samala. The structures of these compounds were elucidated by detailed spectroscopic analysis and by comparison of their spectroscopic data with those reported in the literature. The absolute configuration of 1 and 2a were determined by extensive DFT calculations.

scholarly journals Massiliamide, a cyclic tetrapeptide with potent tyrosinase inhibitory properties from the Gram-negative bacterium Massilia albidiflava DSM 17472T

2020 ◽  
Author(s):  
Andri Frediansyah ◽  
Jan Straetener ◽  
Heike Brötz-Oesterhelt ◽  
Harald Gross
Keyword(s):  
Absolute Configuration ◽  
Inhibitory Activity ◽  
Liquid Culture ◽  
Spectroscopic Analysis ◽  
2D Nmr ◽  
Negative Bacterium ◽  
Gram Negative ◽  
The Absolute ◽  
Potent Inhibitory Activity ◽  
Cyclic Tetrapeptide

AbstractA cyclic tetrapeptide, designated massiliamide, was isolated from the liquid culture of the Gram-negative bacterium Massilia albidiflava DSM 17472T. The structure was elucidated through extensive spectroscopic analysis, including HR-MS and 1D and 2D NMR experiments. The absolute configuration was determined using the Marfey´s method. Massiliamide showed potent inhibitory activity towards tyrosinase with an IC50 value of 1.15 µM and no cytotoxicity.

scholarly journals Two New Piperazine-Triones from a Marine-Derived Streptomycetes sp. Strain SMS636

Marine Drugs ◽  
2019 ◽  
Vol 17 (3) ◽  
pp. 186 ◽  
Author(s):  
Xiuli Xu ◽  
Jiahui Han ◽  
Rui Lin ◽  
Steven Polyak ◽  
Fuhang Song
Keyword(s):  
Staphylococcus Aureus ◽  
Minimum Inhibitory Concentration ◽  
Secondary Metabolites ◽  
Deep Sea ◽  
Spectroscopic Analysis ◽  
Inhibitory Concentration ◽  
2D Nmr ◽  
Antibacterial Activities ◽  
Bacillus Calmette Guerin ◽  
Methicillin Resistant

Two new piperazine-triones lansai E and F (1, 2), together with four known secondary metabolites lansai D (3), 1-N-methyl-(E,Z)-albonoursin (4), imidazo[4,5-e]-1,2,4-triazine (5), and streptonigrin (6) were isolated from a deep-sea-derived Streptomycetes sp. strain SMS636. The structures of the isolated compounds were confirmed by comprehensive spectroscopic analysis, including HRESIMS, 1D and 2D NMR. Compound 4 exhibited moderate antibacterial activities against Staphylococcus aureus and methicillin resistant S. aureus (MRSA) with Minimum Inhibitory Concentration (MIC) values of 12.5 and 25 μg/mL, respectively. Compound 6 displayed significant antibacterial activities against S. aureus, MRSA and Bacillus Calmette-Guérin (BCG) with MIC values of 0.78, 0.78 and 1.25 μg/mL, respectively.

scholarly journals ISOLASI SENYAWA ALKALOID TURUNAN FUROKUINOLIN DARI RANTING Toddalia asiatica L. DAN UJI AKTIVITAS ANTIKANKER

2019 ◽  
Vol 3 (2) ◽  
pp. 102
Author(s):  
Mulyadi Tanjung ◽  
Devina Oktari Rahayu ◽  
Tjitjik Srie Tjahjandarie
Keyword(s):  
Anticancer Activity ◽  
Cancer Cells ◽  
1H Nmr ◽  
13C Nmr ◽  
Room Temperature ◽  
Spectroscopic Analysis ◽  
2D Nmr ◽  
Activity Test ◽  
Key Word ◽  
Toddalia Asiatica

AbstrakToddalia asiatica merupakan tumbuhan perdu yang tersebar di Afrika, Asia, Madagascar, dan Australia (Hu et al., 2015). Senyawa metabolit sekunder yang ditemukan tumbuhan Toddalia asiatica L. adalah alkaloid. Ekstraksi senyawa alkaloid dari tumbuhan Toddalia asiatica L. dengan cara maserasi menggunakan pelarut metanol pada suhu kamar. Proses isolasi dilakukan melalui fraksinasi dan pemurnian menggunakan kromatografi kolom gravitasi, dan kromatografi radial. Hasil isolasi yang didapatkan merupakan senyawa alkaloid turunan furokuinolin yaitu skimmianin. Struktur senyawa alkaloid turunan furokuinolin yang  diketahui melalui analisa hasil spektroskopi UV, IR, 1D NMR (1H-NMR dan 13C-NMR),  serta 2D NMR (HMBC dan HMQC) dan uji aktivitas antikanker terhadap sel kanker murin leukemia P-388. Kata kunci : Alkaloid turunan furokuinolin, skimmianin, Toddalia asiatica L., antikanker AbstractToddalia asiatica L. is a bushy plant that spreads in Africa, Asia, Madagascar, and Australia (Hu et al., 2015). The secondary metabolite compound found in Toddalia asiatica L. is alkaloid. Extraction of alkaloid compounds from Toddalia asiatica L. by maceration using methanol at room temperature. The isolation process is diluted by fractionation and purification using column chromatography of gravity and radial chromatography. The result  of isolation is an alkaloid compound derived furokuinolin, skimmianin. The structure of alkaloid compounds derived from furokuinolin known through spectroscopic analysis including UV, IR, 1D NMR (1H-NMR and 13C-NMR), and 2D NMR (HMBC and HMQC) and the anticancer activity test against the cancer cells murine P-388.Key word :    Alkaloid  compound  derived  furokuinolin,  skimmianin,  Toddalia asiatica L., anticancer

scholarly journals A HOPANE TRITERPENOID FROM THE MYCELIUM OF Isaria japonica IN VIETNAM

2017 ◽  
Vol 55 (5) ◽  
pp. 535
Author(s):  
Nguyen Ngoc Tuan ◽  
Tran Thi Kim Anh ◽  
Ping-Chung Kuo ◽  
Tran Dinh Thang
Keyword(s):  
Spectral Data ◽  
13C Nmr ◽  
Methanol Extract ◽  
2D Nmr ◽  
1H And 13C Nmr ◽  
Nmr Techniques ◽  
First Time

A hopane triterpenoid (11b, 22-dihydroxyhopane) was isolated from the methanol extract of the mycelium of Isaria japonica in Vietnam. The structure of this compound was elucidated using a combination of 1D and 2D NMR techniques (1H-, 13C-NMR, COSY, HSQC and HMBC). In the study, we reported the comprehensive 1H- and 13C-NMR spectral data of 11b, 22-dihydroxyhopane for the first time.

scholarly journals Enantiodifferentiation by 1H and 13C NMR Spectroscopy (Dirhodium Method) – Selectivity of Oxygen Functionalities

2008 ◽  
Vol 3 (3) ◽  
pp. 1934578X0800300
Author(s):  
Edison Díaz Gómez ◽  
Sándor Antus ◽  
Renáta Ferenczi ◽  
Barbara Rys ◽  
Anna Stankiewicz ◽  
...  
Keyword(s):  
Natural Products ◽  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Density Functional Calculations ◽  
Carbonyl Compounds ◽  
Density Functional ◽  
13C Nmr Spectroscopy ◽  
1H And 13C Nmr ◽  
Chiral Carbonyl Compounds ◽  
Oxygen Atoms

Chiral carbonyl compounds can easily be enantiodifferentiated by the dirhodium method. The rhodium atoms reveal a remarkable selectivity in binding to oxygen atoms, which is of great advantage for discriminating chiral polyoxygenated natural products. Amides are the strongest ligands followed by ketones and esters; ethers and alcohols/phenols are even less effective. This sequence is rationalized by electronic charges at the oxygen atoms, as obtained from density functional calculations.

scholarly journals 1H and 13C NMR Spectra of Natural Products Laurene-Type Sesquiterpenes: Theoretical and Experimental Studies

2014 ◽  
Vol 26 (19) ◽  
pp. 6623-6629
Author(s):  
Walied Mohamed Alarif ◽  
Mohamed Hassan Abdel-Rhman ◽  
Ahmed Abdel-Lateff ◽  
Sultan Samran Al-Lihaibi
Keyword(s):  
Natural Products ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Experimental Studies ◽  
13C Nmr Spectra ◽  
1H And 13C Nmr

scholarly journals Microwave-Assisted Synthesis and Properties of Novel Hexaazatrinaphthylene Dendritic Scaffolds

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5038
Author(s):  
Daniel García Velázquez ◽  
Rafael Luque ◽  
Ángel Gutiérrez Ravelo
Keyword(s):  
Cyclic Voltammetry ◽  
Organic Synthesis ◽  
Elemental Analysis ◽  
13C Nmr ◽  
Water Soluble ◽  
Microwave Assisted Synthesis ◽  
1H And 13C Nmr ◽  
Maldi Tof Ms ◽  
Microwave Assisted ◽  
Tof Ms

A novel family of water-soluble π-conjugated hexaazatrinaphthylenes-based dendritic architectures constructed by hexaketocyclohexane and 1,2,4,5-benzenetetramine units is developed in a microwave-assisted organic synthesis (MAOS) approach. The structures and purity of these compounds are verified by 1H and 13C-NMR, MALDI-TOF MS, UV-vis, elemental analysis, DSC, AFM, STM and cyclic voltammetry.

Study on Pyrrole 4-Pyrazoline Derivatives: Experimental and Quantum Chemical Approaches

2016 ◽  
Vol 69 (6) ◽  
pp. 672 ◽  
Author(s):  
R. N. Singh ◽  
Poonam Rawat ◽  
Vikas Baboo
Keyword(s):  
Dft Calculations ◽  
13C Nmr ◽  
Quantum Chemical ◽  
Density Functional ◽  
Electronic Absorption Spectra ◽  
Quantum Chemical Study ◽  
Basis Set ◽  
Dft Methods ◽  
Pyrrole Derivatives ◽  
1H And 13C Nmr

As part of a study on pyrrole derivatives we report here a combined experimental and quantum chemical study of pyrrole 4-pyrazoline biheterocyclic derivatives. The structure of the synthesised compounds have been studied using experimental IR, UV, 1H and 13C NMR spectroscopic analyses along with density functional theory (DFT) calculations using the B3LYP functional with 6–311+G (d,p) basis set. The global, local reactivity, and thermodynamic parameters support the analysis. All the experimental vibrational bands have been discussed and assigned to normal modes on the basis of our calculations. In addition, the computed 1H and 13C NMR data, obtained by DFT calculations, are found to be in good agreement with the experimental data and serve as valuable tools in identifying the products. The vibrational analysis shows red shifts in vN–H and vC=O stretching vibrations as a result of dimer formation. The theoretical electronic absorption spectra have been calculated by using time dependent-DFT methods. The static first hyperpolarizability (β0) values for the synthesized pyrrole–pyrazoline derivatives 4A–D are calculated as 16.97 × 10–30, 47.64 × 10–30, 65.40 × 10–30, 65.39 × 10–30 esu, respectively, and increase from 4A to 4C as a result of the addition of an –NO2 acceptor in 4B and two –NO2 group acceptors in 4C. However, an additional –Cl group in 4D on the phenyl ring attached to the pyrazoline moiety does not result in a clear change from 4C. The calculated static and dynamic hyperpolarizability results show that the investigated molecules might be used as non-linear optical materials.

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