Thiotagetin A, a new cytotoxic thiophene from <i>Tagetes minuta</i>

<p>Phytochemical investigation of the <i>n</i>-hexane fraction of the methanolic extract of <i>Tagetes minuta</i> L. (Asteraceae) aerial parts afforded a new thiophene derivative: thiotagetin A (<b>3</b>), together with β-sitosterol (<b>1</b>) and stigmasterol (<b>2</b>). The structure of the new thiophene was identified by UV, IR, 1D (¹H and ¹³C), 2D (¹H–¹H COSY, HSQC and HMBC) NMR and HRESIMS spectral data. Compound <b>3</b> displayed cytotoxic activity against KB and MCF7 cancer cell lines with ED₅₀ values of 2.03 and 3.88 μg/mL, respectively, compared to adriamycin (0.26 and 0.07 μg/mL, respectively).</p

Terrenolide S, a new antileishmanial butenolide from the endophytic fungus <i>Aspergillus terreus</i>

<p>Terrenolide S, a new butenolide derivative (<b>6</b>), together with six known compounds: (22<i>E</i>,24<i>R</i>)-stigmasta-5,7,22-trien-3-<i>β</i>-ol (<b>1</b>), stigmast-4-ene-3-one (<b>2</b>), stigmasta-4,6,8(14),22-tetraen-3-one (<b>3</b>), terretonin A (<b>4</b>), terretonin (<b>5</b>) and butyrolactone VI (<b>7</b>) have been isolated from the endophytic fungus <i>Aspergillus terreus</i> isolated from the roots of <i>Carthamus lanatus</i> (Asteraceae). Their structures were established by extensive spectroscopic analyses (1D, 2D NMR and HRESIMS), as well as optical rotation measurement and comparison with literature data. Compound <b>1</b> displayed a potent activity towards methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) and <i>Cryptococcus neoformans</i> with IC₅₀ values of 2.29 and 10.68 µM, respectively. Moreover, <b>1</b>, <b>2</b> and <b>6</b> exhibited antileishmanial activity towards <i>Leishmania donovani</i> with IC₅₀ values of 11.24, 15.32 and 27.27 µM, respectively and IC₉₀ values of 14.68, 40.56 and 167.03 µM, respectively.</p

Callyptide A, a new cytotoxic peptide from the Red Sea marine sponge <i>Callyspongia</i> species

<p>In the course of our continuing efforts to allocate bioactive secondary metabolites from Red Sea marine invertebrates, we have investigated the sponge <i>Callyspongia</i> species. The cytotoxic dichloromethane fraction of the methanolic extract of the sponge afforded a new cytotoxic peptide named callyptide A (<b>1</b>). Its structure was determined by extensive 1D and 2D NMR (COSY, HSQC and HMBC) studies and high-resolution mass spectral determination. The configuration of the amino acids was determined by Marfey’s analysis. Callyptide A was found to exhibit growth inhibitory activity when tested against different cancer cell lines.</p