Synthesis and Biological Activity Of Unsymmetrical Bis-Steroidal Pyrazines Related to the Cytotoxic Marine Natural Product Cephalostatin 1

1994 ◽  
Vol 59 (22) ◽  
pp. 6828-6839 ◽  
Author(s):  
Clayton H. Heathcock ◽  
Stephen C. Smith
Keyword(s):  
Biological Activity ◽  
Natural Product ◽  
Marine Natural Product ◽  
Cephalostatin 1

Toward the Synthesis of Rimarikiamide A

2021 ◽  
Author(s):  
◽  
Ashton Nikylla Asbury
Keyword(s):  
Biological Activity ◽  
New Zealand ◽  
Natural Product ◽  
Therapeutic Agent ◽  
Starting Material ◽  
Marine Natural Product ◽  
Full Potential ◽  
Linear Product

<p>Rimarikiamide A is a linear diterpenoid marine natural product featuring an unusual taurine structural moiety. Rimarikiamide A was isolated from the sea sponge Latrunculia brevis found in the Rimariki Islands in northern New Zealand, and was shown to elicit low μM cytotoxicity against HL-60 cells. Unfortunately, only 400 μg of rimarikiamide A was isolated from 700 g of sea sponge, making the characterisation of the two chiral centres impossible by spectroscopic means. To explore the full potential of rimarikiamide A as a therapeutic agent, the molecule must be synthesised in a stereoselective manner or from a starting material of known stereochemistry, fully characterised, and tested for biological activity. A Barbier coupling of two terpene units is required early in the proposed synthesis of Rimarikiamide A, and previous attempts have failed to generate the desired linear product. In this work, the suitability of a titanium-mediated Barbier coupling was investigated, and proved successful for the generation of the desired linear product.</p>

Toward the Synthesis of Rimarikiamide A

2021 ◽  
Author(s):  
◽  
Ashton Nikylla Asbury
Keyword(s):  
Biological Activity ◽  
New Zealand ◽  
Natural Product ◽  
Therapeutic Agent ◽  
Starting Material ◽  
Marine Natural Product ◽  
Full Potential ◽  
Linear Product

<p>Rimarikiamide A is a linear diterpenoid marine natural product featuring an unusual taurine structural moiety. Rimarikiamide A was isolated from the sea sponge Latrunculia brevis found in the Rimariki Islands in northern New Zealand, and was shown to elicit low μM cytotoxicity against HL-60 cells. Unfortunately, only 400 μg of rimarikiamide A was isolated from 700 g of sea sponge, making the characterisation of the two chiral centres impossible by spectroscopic means. To explore the full potential of rimarikiamide A as a therapeutic agent, the molecule must be synthesised in a stereoselective manner or from a starting material of known stereochemistry, fully characterised, and tested for biological activity. A Barbier coupling of two terpene units is required early in the proposed synthesis of Rimarikiamide A, and previous attempts have failed to generate the desired linear product. In this work, the suitability of a titanium-mediated Barbier coupling was investigated, and proved successful for the generation of the desired linear product.</p>

Selective transformations of cephalostatin analogues

2011 ◽  
Vol 83 (3) ◽  
pp. 699-707 ◽  
Author(s):  
Mansour M. Nawasreh
Keyword(s):  
Salicylic Acid ◽  
Natural Product ◽  
Ring Opening ◽  
Biologically Active ◽  
Oxidation Products ◽  
Marine Natural Product ◽  
Electronic Nature ◽  
Reaction Type ◽  
Cephalostatin 1 ◽  
F Ring

The highly tumor inhibitory cephalostatins (e.g., cephalostatin 1), a marine natural product isolated from Cephalodiscus gilcristi, have attracted us to synthesize biologically active analogues. The goal of this study is to shed more light on selective desymmetrization of a symmetrical starting analogue through the F-ring opening route applied to certain analogues using different borane complexes. Previously, we have reported a selective opening of the spiroketal in the northern part of an analogue using catechol-borane and D-(N-tosyl) valine-borane complexes. We demonstrate here the possibility of opening the southern part of the same analogue using salicylic acid-borane complex by which extra flexibility is harvested. In contrast, a different reaction type took place when another analogue was treated with 3,4-diaminobenzonitrile-borane complex, which give after H2O2 oxidation, products arising from ∆14 bond hydration. This led us to conclude that the geometry of both borane complex and substrate govern the regioselectivity of the products. However, the electronic nature of both substrate and borane-complex govern the chemoselectivity.

Progress Toward The Total Synthesis Of The Marine Natural Product Karlotoxin 5

Planta Medica ◽  
2013 ◽  
Vol 79 (10) ◽  
Author(s):  
M Albadry ◽  
Y Zou ◽  
Y Takahashi ◽  
A Waters ◽  
M Hossein ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Marine Natural Product

Actin-binding Comparisons of the Marine Natural Product Latrunculin B with Natural and Semi-synthetic Latrunculin B Analogs

Planta Medica ◽  
2008 ◽  
Vol 74 (03) ◽  
Author(s):  
JJ Bowling ◽  
PR Daga ◽  
S Odde ◽  
SA Ahmed ◽  
MK Mesbah ◽  
...  
Keyword(s):  
Natural Product ◽  
Marine Natural Product ◽  
Actin Binding ◽  
Latrunculin B
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