Analogues of 2-crotonyloxymethyl-(4R,5R,6R)-4,5,6-trihydroxycyclohex-2-enone (COTC) with anti-tumor properties

Concise total synthesis of (+)-Zeylenone with antitumor activity and the structure-activity relationship of its derivatives

Natural products--polyoxygenated cyclohexenes exhibited potent anti-tumor activity, such as zeylenone, which is a natural product isolated from Uvaria grandiflora Roxb. This article will attempt to establish a gram-scale synthesis method of (+)-zeylenone and explain the structure-activity relationship of this kind of compound. Total synthesis of (+)-zeylenone was completed in 13 steps with quinic acid as the starting material in 9.8% overall yield. The highlight of the route was the control of the three carbon's chirality by single step dihydroxylation. In addition, different kinds of derivatives were designed and synthesized. Cell Counting Kit-8 (CCK8) assay was used for evaluating antitumor activity against three human cancer cell lines. The structure--activity relationship suggested that compounds with both absolute configurations exhibited tumor-suppressive effects. Moreover, hydroxyls at the C-1/C-2 position were crucial to the activity, and the esterification of large groups at C-1 hydroxyl eliminated the activity. Hydroxyl at the C-3 position was also important as proper ester substituent could increase the potency.

Direct Synthesis of α-Fluoro-α-Triazol-1-yl Ketones from Sulfoxonium Ylides: A One-Pot Approach

The work reported herein showcases a new route to access α-fluoro-α-triazol-1-yl ketones from sulfoxonium ylides via α-azido-α-fluoro ketone intermediates. In a one-pot, two-step sequence, the ketosulfoxonium reactant initially undergoes insertion of F⁺ and N₃^-, followed by a subsequent CuAAC reaction with arylacetylenes to install a 1,4-triazolo moiety. The approach allows for modification to both the sulfoxonium ylide and arylacetylene reactants. Fifteen examples have been reported, with yields ranging between 22% and 75%.

Catalyst free synthesis of α-fluoro-β-hydroxy ketones/α-fluoro-ynols via electrophilic fluorination of tertiary propargyl alcohols using Selectfluor™ (F-TEDA-BF4)

A facile access to α-fluoro-β-hydroxyketones via electrophilic fluorination.

Biosynthesis and Biological Activity of Carbasugars

The first synthesis of carbasugars, compounds in which the ring oxygen of a monosaccharide had been replaced by a methylene moiety, was described in 1966 by Professor G. E. McCasland’s group. Seven years later, the first true natural carbasugar (5a-carba-R-D-galactopyranose) was isolated from a fermentation broth of Streptomyces sp. MA-4145. In the following decades, the chemistry and biology of carbasugars have been extensively studied. Most of these compounds show interesting biological properties, especially enzymatic inhibitory activities, and, in consequence, an important number of analogues have also been prepared in the search for improved biological activities. The aim of this review is to give coverage on the progress made in two important aspects of these compounds: the elucidation of their biosynthesis and the consideration of their biological properties, including the extensively studied carbapyranoses as well as the much less studied carbafuranoses.

A synthetic approach to novel carvotacetone and antheminone analogues with anti-tumour activity

A synthetic approach to analogues of the terpenoid natural product antheminone A is described which employs (-)-quinic acid as starting material. A key conjugate addition step proved to be unpredictable regarding its stereochemical outcome however the route allowed access to two diastereoisomeric series of compounds. The results of biological assay of the toxicity of the target compounds towards non-small-cell lung cancer cell line A549 are reported.

Synthesis of chiral hydroxylated enones as potential anti-tumor agents

A series of chiral hydroxylated enones were synthesized as COTC ether analogues to investigate the structural features required for optimal and selective anti-tumor activity. The cytotoxicity of the seven COTC ether analogues against WRL-68 normal and HepG2, HL-60 cancer cell lines were measured. C-4 ether analogues with an aliphatic chain substituent were found to be more favorable than their aromatic counterparts. Inversion of the configuration at C-4 in 5e to give 5f only resulted in reduced selectivity towards cancer cells. These results show that 4-O-pentyl-gabosine D (5e) has optimum selectivity and cytotoxicity towards two cancer cell lines.

Synthetic efforts for stereo structure determination of cytotoxic marine natural product pericosines as metabolites of Periconia sp. from sea hare

Pericosines are unique C₇ cyclohexenoid metabolites of Periconia byssoides OUPS-N133 fungus that was originally isolated from the sea hare, Aplysia kurodai. Pericosines show significant in vitro cytotoxicity against P388 lymphocytic leukemia cells. Pericosine A, in particular, shows the most potent activity and significant in vivo antitumor activity against P388 cells. Thus, pericosines are promising candidates for seed compounds of anticancer drugs. However, before the total syntheses of pericosines were accomplished, their stereo structures could not be determined by spectral analyses because they have multi-functionalized cyclohexenoid structures with torsional strain. In this review, synthetic efforts for pericosines in this decade are surveyed.

New cytotoxic saturated and unsaturated cyclohexanones from Anthemis maritima

Two new cyclohexenones (antheminones A and B) and a new cyclohexanone, (antheminone C) along with five known compounds were isolated from the leaves of Anthemis maritima L. The structures were mainly deduced from extensive 1D and 2D NMR spectroscopy and mass spectrometry. The new compounds were tested in vitro for their cytotoxic activity against adherent and non-adherent cancer cell lines. Antheminones A and C exhibited significant antiproliferative activity against leukemia cells with IC(50) values ranging from 3.2 to 14 microM.

Arene cis-dihydrodiols: Useful precursors for the preparation of analogues of the anti-tumour agent, 2-crotonyloxymethyl-(4R,5R,6R)-4,5,6-trihydroxycyclohex-2-enone (COTC)

The synthesis of 6-epi-COTC, a diastereoisomer of Streptomyces metabolite 2-crotonyloxymethyl-(4R,5R,6R)-4,5,6-trihydroxycyclohex-2-enone (COTC), is described. The anti-cancer activities of the novel analogue, in racemic and enantiomerically pure forms, are presented.