MMB triazole analogs are potent NF-κB inhibitors and anti-cancer agents against both hematological and solid tumor cells

Triazole derivatives of melampomagnolide B (MMB) have been synthesized via click chemistry methodologies and screened against a panel of 60 human cancer cell lines. Several derivatives showed promising anti-cancer activity, affording growth inhibition (GI50) values in the nanomolar range (GI50 = 0.02–0.99 μM). Lead compound 7h exhibited EC50 values of 400 nM and 700 nM, respectively, against two AML clinical specimens. Compound 7h was significantly more potent than parthenolide as an inhibitor of p65 phosphorylation in both hematological and solid tumor cell lines, indicating its ability to inhibit the NF-κB pathway. In TMD-231 breast cancer cells, treatment with 7h reduced DNA binding activity of NF-κB through inhibition of IKK-β mediated p65 phosphorylation and caused elevation of basal IκBα levels through inhibition of constitutive IκBα turnover and NF-κB activation. Molecular docking and dynamic modeling studies indicated that 7h interacts with the kinase domain of the monomeric IKKβ subunit, leading to inhibition of IKKβ activation, and compromising phosphorylation of downstream targets of the NF-κB pathway; dynamic modeling studies show that this interaction also causes unwinding of the α-helix of the NEMO binding site on IKKβ. Molecular docking studies with 10, a water-soluble analog of 7h, demonstrate that this analog interacts with the dimerization/oligomerization domain of monomeric IKKβ and may inhibit oligomer formation and subsequent autophosphorylation. Sesquiterpene lactones 7h and 10 are considered ideal candidates for potential clinical development

Crystal structure of ( E

The title compound, C33H35NO6 [systematic name: (Z)-3-(4-{(E)-[(E)-1a,5-dimethyl-9-oxo-2,3,7,7a-tetrahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-8(1aH,6H,9H,10aH,10bH)-ylidene]methyl}phenyl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile methanol hemisolvate], C33H35NO6·0.5CH3OH, was prepared by the reaction of (Z)-3-(4-iodophenyl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile with parthenolide [systematic name: (E)-1a,5-dimethyl-8-methylene-2,3,6,7,7a,8,10a,10b-octahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-9(1aH)-one] under Heck reaction conditions. The molecule is built up from fused ten-, five- (lactone) and three-membered (epoxide) rings with a {4-[(Z)-2-cyano-2-(3,4,5-trimethoxyphenyl)ethenyl]phenyl}methylidene group as a substituent. The 4-[(Z)-2-cyano-2-(3,4,5-trimethoxyphenyl)ethenyl]phenyl group on the parthenolide exocyclic double bond is oriented in a trans position to the lactone ring to form the E isomer. The dihedral angle between the benzene ring of the phenyl moiety and the lactone ring mean plane is 21.93 (4)°

Monosuccinate ester of melampomagnolide B

The title monosuccinate derivative of melampomagnolide B [systematic name: 4-(((1aR,7aS,10aS,10bS,E)-1a-methyl-8-methylene-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-decahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-5-yl)methoxy)-4-oxobutanoic acid], C19H24O7, was obtained from the reaction of melampomagnolide B with succinic anhydride under nucleophilic addition reaction conditions. The molecule is built up from fused ten-, five- (lactone) and three-membered (epoxide) rings. The internal double bond in the ten-membered ring has the cis geometry (i.e. it is the E isomer). The lactone ring has an envelope-type conformation, with the (chiral) C atom opposite the lactone O atoms as the flap atom. In the crystal, O—H...O hydrogen bonds link the molecules into chains parallel to the b-axis direction

Dimers of Melampomagnolide B Exhibit Potent Anticancer Activity against Hematological and Solid Tumor Cells

Novel carbamate (<b>7a</b>–<b>7h</b>) and carbonate (<b>7i</b>, <b>7j</b>, and <b>8</b>) dimers of melampomagnolide B have been synthesized by reaction of the melampomagnolide-B-triazole carbamate synthon <b>6</b> with various terminal diamino- and dihydroxyalkanes. Dimeric carbamate products <b>7b</b>,<b> 7c</b>, and <b>7f</b> exhibited potent growth inhibition (GI₅₀ = 0.16–0.99 μM) against the majority of cell lines in the NCI panel of 60 human hematological and solid tumor cell lines. Compound <b>7f</b> and <b>8</b> exhibited anticancer activity that was 300-fold and 1 × 10⁶-fold more cytotoxic than DMAPT, respectively, at a concentration of 10 μM against rat 9L-SF gliosarcoma cells. Compounds <b>7a</b>–<b>7j</b> and <b>8</b> were also screened against M9-ENL1 and acute myelogenous leukemia (AML) primary cell lines and exhibited 2- to 10-fold more potent antileukemic activity against M9-ENL1 cells (EC₅₀ = 0.57–2.90 μM) when compared to parthenolide (EC₅₀ = 6.0) and showed potent antileukemic activity against five primary AML cell lines (EC₅₀ = 0.76–7.3 μM)