scholarly journals Isolation of Sesquiterpenoids and Steroids from the Soft Coral Sinularia brassica and Determination of Their Absolute Configuration

Marine Drugs ◽  
2021 ◽  
Vol 19 (9) ◽  
pp. 523
Author(s):  
Giang Nam Pham ◽  
Da Yeun Kang ◽  
Min Ju Kim ◽  
Se Jong Han ◽  
Jun Hyuck Lee ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Leishmania Donovani ◽  
Spectroscopic Analysis ◽  
Soft Coral ◽  
Antimicrobial Effect ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
Polyhydroxylated Steroids

Two undescribed rearranged cadinane-type sesquiterpenoids (1–2), named sinulaketol A-B, together with one new chlorinated steroid (3), one new gorgosterol (4), one known sesquiterpene (5), one known dibromoditerpene (6) and two known polyhydroxylated steroids (7–8) were isolated from the soft coral Sinularia brassica. The structures of these compounds were established by extensive spectroscopic analysis, including HRESIMS, 1D, and 2D NMR spectroscopy. Their absolute configurations were also determined by the ECD calculations and DP4+ probability analysis. Antileishmanial activity of compounds 1–8 was evaluated in vitro against the amastigote forms of Leishmania donovani, in which compounds 3, 6, and 7 inhibited the growth of L. donovani by 58.7, 74.3, 54.7%, respectively, at a concentration of 50 μM. Antimicrobial effect of the isolated compounds were also evaluated against Candida albicans, Staphylococcus aureus, and Escherichia coli. Compound 6, a brominated diterpene, exhibited antimicrobial effect against S. aureus.

Determination of the structure of the capsular antigen of Escherichia coli O8:K46:H30, using FABMS and 2D-NMR spectroscopy

1992 ◽  
Vol 231 ◽  
pp. 39-50 ◽  
Author(s):  
Guy G.S. Dutton ◽  
Agyeman Kuma-Mintah ◽  
Stephen K. Ng ◽  
Haralambos Parolis ◽  
Anne Dell ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Nmr Spectroscopy ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
Capsular Antigen

scholarly journals Paralemnolins X and Y, New Antimicrobial Sesquiterpenoids from the Soft Coral Paralemnalia thyrsoide

Antibiotics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1158
Author(s):  
Abdelsamed I. Elshamy ◽  
Tarik A. Mohamed ◽  
Eman M. Elkady ◽  
Ibrahim A. Saleh ◽  
Ahmed A. El-Beih ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Aspergillus Niger ◽  
Spectroscopic Data ◽  
Soft Coral ◽  
2D Nmr ◽  
Organic Extracts

The organic extracts of the Red Sea soft coral Paralemnalia thyrsoides has led to the identification of two neolemnane-type sesquiterpenoids: paralemnolins X and Y (1, 2). In addition to these newly characterized compounds, ten known metabolites (3–12) were isolated. Previously reported compounds were elucidated by literature comparison of spectroscopic data (1D and 2D NMR as well as MS data). In vitro antimicrobial activity was investigated for compounds (1–12) against Staphylococcus aureus, Escherichia coli, Candida albicans and Aspergillus niger. Compound 5 showed antimicrobial activity against all assayed microorganisms.

scholarly journals Structural characteristics of plant cell wall elucidated by solution-state 2D NMR spectroscopy with an optimized procedure

2020 ◽  
Vol 9 (1) ◽  
pp. 650-663
Author(s):  
Wanwan Wang ◽  
Jibao Cai ◽  
Zhenyu Xu ◽  
Yi Zhang ◽  
Fanchao Niu ◽  
...  
Keyword(s):  
Cell Wall ◽  
Quantum Coherence ◽  
Nmr Spectra ◽  
Plant Cell Wall ◽  
Milling Time ◽  
Structural Characteristics ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
Complete Representation

AbstractA method was developed for rapid qualitative determination of lignocellulose in the tobacco cell wall by utilizing 2D heteronuclear single quantum coherence NMR spectra (2D HSQC NMR). Traditional methods for analyzing the structure of lignocellulose involve many steps of separation and extraction, which is labor-intensive. In this work, the whole cell wall was milled and dissolved in deuterium solvent. The solvent dimethylsulfoxide (DMSO-d6) containing hexamethylphosphoramide (HMPA-d18) enhanced swelling of the sample and gave high-resolution spectra. The tobacco samples are ball milled at different ball milling times, and the state of the particles is observed through an electron microscope, and then the probability of the particles being less than 5 µm is counted. Through the comparison of the abundance and integration of the peak signals in the spectra under different transmittances, it was determined that when the milling time was 6 h, the quality of the NMR spectra was the best. The optimum conditions of characterizing tobacco structure were DMSO-d6/HMPA-d18 solution and 6 h milling time. Under these conditions, complete representation of the structure of lignocellulose and simplified process could be achieved.

Homoadamantane and Adamantane Acylphloroglucinols from Hypericum hirsutum

Planta Medica ◽  
2021 ◽  
Author(s):  
Julianna Max ◽  
Jörg Heilmann
Keyword(s):  
Petroleum Ether Extract ◽  
2D Nmr ◽  
Positive Control ◽  
Ionization Mass ◽  
2D Nmr Spectroscopy ◽  
Vitro Assay ◽  
Ionization Mass Spectroscopy ◽  
Ic50 Values ◽  
Adamantane Skeleton

Abstract 1H NMR-guided fractionation of the petroleum ether extract of the aerial parts from Hypericum hirsutum yielded to the isolation of 19 polyprenylated polycyclic acylphloroglucinols. Structure elucidation based on 1D and 2D NMR spectroscopy together with high-resolution electrospray ionization mass spectroscopy revealed 14 acylphloroglucinols with a homoadamantane scaffold (1–14), while 5 further compounds showed an adamantane skeleton (15–19). Except for hookerione C (15), all isolated metabolites are hitherto unknown. While structurally-related metabolites have been isolated from other Hypericum species, it is the first report of admantan and homoadamantan type acylphloroglucinols in section Taeniocarpium Jaub. & Spach (Hypericaceae). The isolated compounds have been tested in a crystal violet-based in vitro assay on their properties to reduce the proliferation of human microvascular endothelial cells compared to hyperforin as the positive control. They showed a moderate reduction of proliferation with IC50 values in the range ~ 3 – 22 µM, with the homoadamantane-based compounds 2 and 4 being the most active. In addition, inhibition of the TNF-α-induced ICAM-1 expression was determined for 1 – 5, 7, and 10 – 12. Substances 3 and 12 reduced the ICAM-1 expression significantly (to 46.7% of control for 3, 62.3% for 12, at 50 µM).

scholarly journals Unusual Polyhydroxylated Steroids from the Starfish Anthenoides laevigatus, Collected off the Coastal Waters of Vietnam

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1440
Author(s):  
Alla A. Kicha ◽  
Dinh T. Ha ◽  
Timofey V. Malyarenko ◽  
Anatoly I. Kalinovsky ◽  
Roman S. Popov ◽  
...  
Keyword(s):  
Coastal Waters ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
Cytotoxic Effects ◽  
One Dimensional ◽  
The Common ◽  
Polyhydroxylated Steroids ◽  
New Compounds ◽  
Ht 29 ◽  
Inhibit Cell Proliferation

Four new polyhydroxylated steroids 1–4 were isolated along with two previously known related steroids 5 and 6 from the methanolic extract of the starfish Anthenoides laevigatus collected off the coastal waters of Vietnam. Structures of new compounds were substantially elucidated by one-dimensional (1D) and two-dimensional (2D) NMR spectroscopy and HRESIMS techniques. Heptaol 1 and hexaol 2 contain the common 5α-cholestane skeleton, while hexaol 3 and heptaol 4 have the rare among starfish steroid compounds 5β-cholestane skeleton. Compounds 1, 5, and 6 do not show cytotoxic effects against normal JB6 Cl41 and cancer HT-29 and MDA-MB-231 cells, however they inhibit cell proliferation and colony formation of cancer HT-29 and MDA-MB-231 cells.

scholarly journals Pigmentosins from Gibellula sp. as antibiofilm agents and a new glycosylated asperfuran from Cordyceps javanica

2019 ◽  
Vol 15 ◽  
pp. 2968-2981 ◽  
Author(s):  
Soleiman E Helaly ◽  
Wilawan Kuephadungphan ◽  
Patima Phainuphong ◽  
Mahmoud A A Ibrahim ◽  
Kanoksri Tasanathai ◽  
...  
Keyword(s):  
Antimicrobial Effect ◽  
Pathogenic Fungi ◽  
2D Nmr ◽  
Biologically Active ◽  
Active Metabolites ◽  
Metabolite Profiles ◽  
Array Detection ◽  
Antibiofilm Agents ◽  
Biologically Active Metabolites

In the course of our exploration of the Thai invertebrate-pathogenic fungi for biologically active metabolites, pigmentosin A (1) and a new bis(naphtho-α-pyrone) derivative, pigmentosin B (2), were isolated from the spider-associated fungus Gibellula sp. Furthermore, a new glycosylated asperfuran 3, together with one new (6) and two known (4 and 5) cyclodepsipeptides, was isolated from Cordyceps javanica. The pigmentosins 1 and 2 showed to be active against biofilm formation of Staphylococcus aureus DSM1104. The lack of toxicity toward the studied microorganism and cell lines of pigmentosin B (2), as well as the antimicrobial effect of pigmentosin A (1), made them good candidates for further development for use in combination therapy of infections involving biofilm-forming S. aureus. The structure elucidation and determination of the absolute configuration were accomplished using a combination of spectroscopy, including 1D and 2D NMR, HRMS, Mosher ester analysis, and comparison of calculated/experimental ECD spectra. A chemotaxonomic investigation of the secondary metabolite profiles using analytical HPLC coupled with diode array detection and mass spectrometry (HPLC–DAD–MS) revealed that the production of pigmentosin B (2) was apparently specific for Gibellula sp., while the glycoasperfuran 3 was specific for C. javanica.

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