Isolation and structure of combretastatin

1982 ◽  
Vol 60 (11) ◽  
pp. 1374-1376 ◽  
Author(s):  
George R. Pettit ◽  
Gordon M. Cragg ◽  
Delbert L. Herald ◽  
Jean M. Schmidt ◽  
Prasert Lohavanijaya
Keyword(s):  
Total Synthesis ◽  
South African ◽  
Spectral Methods ◽  
Biological Evaluation ◽  
Crystallographic Analysis ◽  
Structural Elucidation ◽  
The South ◽  
X Ray

The South African tree Combretumcaffrum has been shown to contain a constituent capable of significantly reversing astrocyte formation employing the National Cancer Institute's 9ASK system. The constituent responsible for astrocyte reversal was isolated and designated combretastatin (1). Structural elucidation was initiated employing spectral methods and completed by X-ray crystallographic analysis. By this means combretastatin was assigned structure 1. Further biological evaluation and a total synthesis are now in progress.

Asymmetric total synthesis, x-ray crystallography, and preliminary biological evaluation of 1-(1'-hydroxyethyl)-25-hydroxyvitamin D3 analogs of natural calcitriol

1993 ◽  
Vol 58 (25) ◽  
pp. 7209-7215 ◽  
Author(s):  
Gary H. Posner ◽  
Haiyan Dai ◽  
Kamyar Afarinkia ◽  
N. Narasimha Murthy ◽  
Kate Z. Guyton ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Biological Evaluation ◽  
Asymmetric Total Synthesis ◽  
X Ray ◽  
X Ray Crystallography

scholarly journals Total Synthesis and Biological Evaluation of Phaeosphaerides

Catalysts ◽  
2018 ◽  
Vol 8 (5) ◽  
pp. 206 ◽  
Author(s):  
Kenichi Kobayashi ◽  
Kosaku Tanaka ◽  
Hiroshi Kogen
Keyword(s):  
Crystal Structure ◽  
Natural Products ◽  
Total Synthesis ◽  
Structure Analysis ◽  
Endophytic Fungus ◽  
Biological Evaluation ◽  
Crystal Structure Analysis ◽  
X Ray ◽  
Structure Activity ◽  
Synthesis And Biological Evaluation

This article reviews studies regarding the total synthesis of phaeosphaerides A and B, nitrogen-containing bicyclic natural products isolated from an endophytic fungus. Numerous synthetic efforts and an X-ray crystal structure analysis of phaeosphaeride A have enabled revision of its originally proposed structure. In addition, a successful protic acid-mediated transformation of phaeosphaeride A to phaeosphaeride B revealed the hypothetical biosynthesis of phaeosphaeride B from phaeosphaeride A. Structure–activity relationship studies of phaeosphaeride derivatives are also discussed.

An Approach to the Total Synthesis of Diterpenoid Plant Growth Substances Isolated From Gametophytes of the Fern Genus Anemia

1992 ◽  
Vol 45 (1) ◽  
pp. 227 ◽  
Author(s):  
CKF Chiu ◽  
LN Mander ◽  
AD Stuart ◽  
AC Willis
Keyword(s):  
Total Synthesis ◽  
Liquid Ammonia ◽  
Crystallographic Analysis ◽  
Aldol Reactions ◽  
Growth Substances ◽  
Enol Ether ◽  
X Ray ◽  
Relative Stereochemistry ◽  
Plant Growth Substances

Reduction of the oxoindan acid (9) by potassium in liquid ammonia followed by in situ alkylation with 3-methylbut-2-enyl bromide furnished enol ether (14) which was transformed into the acetal (17) and thence aldehydes (18; R = COCH3 and COCHCl2). Acid- catalysed aldol reactions then afforded the ethanoindene derivatives (19; R=COCH3 and COCHCl2). Further elaboration gave carbinol (28) which is envisaged as an intermediate for the total synthesis of the diterpenoid antheridiogens obtained from gametophytes of the fern genus Anemia, including acid (2). The relative stereochemistry of acetal (17) was established by X-ray crystallographic analysis.

scholarly journals Synthesis, X-ray crystallographic analysis, DFT studies and biological evaluation of triazolopyrimidines and 2-anilinopyrimidines

2021 ◽  
pp. 132092
Author(s):  
Mohamed Fares ◽  
Peter Canfield ◽  
Muhammad A. Alsherbiny ◽  
William Lewis ◽  
Anthony C. Willis ◽  
...  
Keyword(s):  
Biological Evaluation ◽  
Crystallographic Analysis ◽  
Dft Studies ◽  
X Ray

scholarly journals X-ray Micro-Ct Supporting the South African Additive Manufacturing Community †

2018 ◽  
Author(s):  
Anton du Plessis ◽  
S.G. le Roux
Keyword(s):  
Additive Manufacturing ◽  
South African ◽  
Process Optimization ◽  
Manufacturing Industry ◽  
Full Potential ◽  
Quality Inspection ◽  
Micro Ct ◽  
The South ◽  
X Ray ◽  
Non Destructive

This paper presents the latest developments in microCT, both globally and locally, for supporting the additive manufacturing industry. There are a number of recently developed capabilities which are especially relevant to the non-destructive quality inspection of additive manufactured parts; and also for advanced process optimization. These new capabilities are all locally available but not yet utilized to their full potential, most likely due to a lack of knowledge of these capabilities. The aim of this paper is therefore to fill this gap and provide an overview of these latest capabilities, showcasing numerous local examples.

scholarly journals A Brønsted base-promoted diastereoselective dimerization of azlactones

2017 ◽  
Vol 13 ◽  
pp. 2663-2670 ◽  
Author(s):  
Danielle L J Pinheiro ◽  
Gabriel M F Batista ◽  
Pedro P de Castro ◽  
Leonã S Flores ◽  
Gustavo F S Andrade ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Crystallographic Analysis ◽  
Base System ◽  
Reaction Monitoring ◽  
Kinetic Reaction ◽  
X Ray ◽  
H Nmr ◽  
Relative Stereochemistry ◽  
Brønsted Base ◽  
Reaction Profile

A novel Brønsted base system for the diastereoselective dimerization of azlactones using trichloroacetate salts and acetonitrile has been developed. Desired products were obtained in good yields (60–93%) and with up to >19:1 dr after one hour of reaction. Additionally, the relative stereochemistry of the major dimer was assigned as being trans, by X-ray crystallographic analysis. The kinetic reaction profile was determined by using 1H NMR reaction monitoring and revealed a second order overall kinetic profile. Furthermore, by employing this methodology, a diastereoselective total synthesis of a functionalized analogue of streptopyrrolidine was accomplished in 65% overall yield.

scholarly journals Concise Diastereoselective Total Synthesis of (±)-Parvistemonine A

Synlett ◽  
2020 ◽  
Vol 31 (18) ◽  
pp. 1800-1804
Author(s):  
Kazuyuki Sugita ◽  
Rintaro Matsuo ◽  
Ayumu Miyashita ◽  
Motoi Kuwabara ◽  
Shinya Adachi ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Michael Addition ◽  
Wittig Reaction ◽  
Crystallographic Analysis ◽  
Mitsunobu Reaction ◽  
X Ray ◽  
Linear Sequence ◽  
Relative Stereochemistry ◽  
Key Steps ◽  
First Time

AbstractWe have developed a concise diastereoselective total synthesis of (±)-parvistemonine A. By using a Mukaiyama–Michael addition, an aza-Wittig reaction, a Paal–Knorr pyrrole synthesis, an acid-mediated annulation, and a Mitsunobu reaction as key steps, we achieved a total synthesis in which the longest linear sequence was ten steps and the overall yield was 19.6%. Additionally, the relative stereochemistry of parvistemonine A was confirmed by X-ray crystallographic analysis for the first time.

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