scholarly journals Theonellamides J and K and 5-cis-Apoa-theopalauamide, Bicyclic Glycopeptides of the Red Sea Sponge Theonella swinhoei

Marine Drugs ◽  
2021 ◽  
Vol 20 (1) ◽  
pp. 31
Author(s):  
Ohad Hasin ◽  
Shani Shoham ◽  
Yoel Kashman ◽  
Micha Ilan ◽  
Shmuel Carmeli

Theonella swinhoei is a fairly common inhabitant of reefs throughout the Indian and Pacific Oceans. Metabolomic analyses of samples of T. swinhoei collected in different depths in the Gulf of Aqaba revealed two chemotypes differing in the profiles of the theonellamides they produce, some of which seem to be unknown. Driven by this finding, we examined a sample of T. swinhoei collected more than 40 years ago in the southern part of the Gulf of Aqaba. Large-scale extract of this sample yielded four theonellamides, the known theopalauamide (4), as the major component, and three new metabolites, theonellamide J (1), 5-cis-Apoa-theopalauamide (2), and theonellamide K (3), as the minor components. The planar structure of these complex cyclic glycopeptides was elucidated by combination of 1D and 2D NMR techniques and HRESIMS. The absolute configuration of the amino acids was established by Marfey’s and advanced Marfey’s methods, and the absolute configuration of its galactose unit using “Tanaka’s method” for monosaccharides. The biological activity of the pure compounds was tested for antibacterial activity and for cytotoxicity to HTC-116 cell line. The compounds presented significant cytotoxicity against the HTC-116 cell line, illuminating the importance of the Apoa subunit for the activity.

2013 ◽  
Vol 8 (5) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Li-She Gan ◽  
Jin-Jie Chen ◽  
Man-Fei Shi ◽  
Chang-Xin Zhou

A new homoisoflavanone, (3 R)-5,7-dihydroxy-8-methyl-3-(2′-hydroxy-4′-methoxybenzyl)-chroman-4-one (1), was isolated from the 95% ethanol extract of the rhizomes of Polygonatum cyrtonema. The structure of 1 was determined by spectroscopic methods, especially 2D NMR techniques. Quantum chemical TD DFT calculations of the theoretical ECD spectrum of 1 allowed assignment of the absolute configuration as 3R.


Author(s):  
Anat Lodin-Friedman ◽  
Shmuel Carmeli

During blooms, cyanobacteria produce diverse modified peptides. Among these are the microginins, which inhibit zinc-containing metalloproteases. Ten microginins, microginins KR767 (1), KR801(2), KR835 (3), KR785 (4), KR604 (5), KR638 (6), KR781 (7), KR815 (8), FR3 (9), and FR4 (10) were isolated from the extract of a bloom material of Microcystis sp. (IL-405) collected from the Kishon Reservoir, Israel in the fall of 2009. The structures of the pure compounds were elucidated using 1D and 2D NMR techniques and high-resolution mass spectrometry. The absolute configuration of the chiral centers of the amino acids were determined by Marfey’s and advance Marfey’s methods and by comparison of 1H and 13C NMR chemical shifts of the Ahda derivatives with those of known microginins. These microginins differ in sequence and absolute configuration of the chiral centers of the Ahda moieties and by N-methylation of Ahda amine group and extent of chlorination of Ahda terminal methyl group. The compounds were evaluated for inhibition of the zinc metalloprotease aminopeptidase M and exhibited low- to sub-nanomolar IC50 values.


Author(s):  
Andri Frediansyah ◽  
Jan Straetener ◽  
Heike Brötz-Oesterhelt ◽  
Harald Gross

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.


2014 ◽  
Vol 9 (9) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Juan D. Hernández-Hernández ◽  
Hugo A. García-Gutiérrez ◽  
Luisa U. Román-Marín ◽  
Yunuen I. Torres-Blanco ◽  
Carlos M. Cerda-García-Rojas ◽  
...  

The stems of Bursera multijuga afforded (-)-(1 S,3 E,7 R,8 R,11 E)-7,8-epoxycembra-3,11-dien-1-ol (1) and its acetate 2, together with cembrene A (3), nephthenol (4), and cembrenol (5). The structures of 1 and 2 were elucidated by 1D and 2D NMR, HRESIMS, and X-ray diffraction. The conformational preference of flexible 1 was studied by molecular modeling at the DFT B3LYP/DGDZVP level of theory. Good agreement between calculated and experimental vibrational circular dichroism curves established the absolute configuration of 1. This is the first time that cembrane derivatives have been isolated from the genus Bursera.


2008 ◽  
Vol 3 (5) ◽  
pp. 1934578X0800300
Author(s):  
Viqar Uddin Ahmad ◽  
Farman Ullah ◽  
Hidayat Hussain ◽  
Gilles Dujardin ◽  
Arnaud Martel ◽  
...  

Two new bisflavan-3-ols, named colletinin A (1) and 2,2″-diepicolletinin A (2) have been isolated from Rhododendron collettianum. Their structures were determined by means of 1D and 2D NMR analysis, aided by HREIMS data. The relative configuration was determined by means of 1H-1H NOESY correlation but the absolute configuration could not be established.


2018 ◽  
Vol 13 (8) ◽  
pp. 1934578X1801300
Author(s):  
Uraiwan Sriphana ◽  
Chavi Yenjai ◽  
Siriporn Tungnoi ◽  
Jongjai Srirapa ◽  
Auemporn Junsongduang

Two known chalcones (1–2), five known flavonol derivatives (3 and 5–8) and one flavone (4) were isolated for the first time from fruits of Millettia leucantha Kurz. In addition, 5 was found for the first time from this genus. Their structures were elucidated on the basis of IR, MS, 1D and 2D NMR techniques. Chalcone 1 exhibited moderate cytotoxicity against the MCF-7 cell line with an IC50 value of 50.93 μM, whereas this compound showed inactive cytotoxicity against Vero cells. Compound 2 exhibited cytotoxicity against the KB, NCI-H187 and Vero cell lines with IC50 values of 63.64, 114.44 and 28.44 μM, respectively. Compound 8 only showed cytotoxic activity against the KB cell line with an IC50 value of 110.23 μM.


2015 ◽  
Vol 10 (12) ◽  
pp. 1934578X1501001 ◽  
Author(s):  
Cai-Yun Gao ◽  
Ting Ma ◽  
Jun Luo ◽  
Ling-Yi Kong

Physagulides M-O, three new withanolides (1–3), were isolated from the aerial parts of Physalis angulata L. Their structures were elucidated through extensive spectroscopic techniques, including 1D and 2D NMR, and HRESIMS. The absolute configurations (22- R) of these new compounds were determined by CD analysis. Compounds 1 and 3 showed significant selective cytotoxic activities on the MG-63 cell line, with IC50 values of 4.28 and 5.44 μM, respectively.


2013 ◽  
Vol 9 ◽  
pp. 1643-1651 ◽  
Author(s):  
Annamaria Sinisi ◽  
Barbara Calcinai ◽  
Carlo Cerrano ◽  
Henny A Dien ◽  
Angela Zampella ◽  
...  

Chemical analysis of the organic extract of Theonella swinhoei yielded two new tridecadepsipeptides of the theonellapeptolide family, namely sulfinyltheonellapeptolide, characterized by a methylsulfinylacetyl group at the N-terminus, and theonellapeptolide If, the first member of this class of compounds to show four valine residues. The structures of the compounds, isolated along with the known theonellapeptolide Id, were determined by extensive 2D NMR and MS/MS analyses followed by application of Marfey’s method. The isolated peptides exhibited moderate antiproliferative activity against HepG2 cells, a hepatic carcinoma cell line.


2008 ◽  
Vol 3 (2) ◽  
pp. 1934578X0800300
Author(s):  
Sloan Ayers ◽  
Deborah L. Zink ◽  
Robert Brand ◽  
Seef Pretorius ◽  
Dennis Stevenson ◽  
...  

Struthiolanone (1), a flavanone-resveratrol adduct, was isolated from Struthiola argentea. Its structure was determined by high-resolution mass spectrometry and 1D- and 2D-NMR spectroscopic techniques. The absolute configuration was determined by comparison of the CD spectrum of biflavonoids. This compound appears to be the first example of a flavanoid-stilbene adduct.


1993 ◽  
Vol 4 (7) ◽  
pp. 1527-1532 ◽  
Author(s):  
T. Pehk ◽  
E. Lippmaa ◽  
M. Lopp ◽  
A. Paju ◽  
B.C. Borer ◽  
...  

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