New cytotoxic cycloartane triterpene from <i>Cassia italica</i> aerial parts

<div><p>Phytochemical study of the aerial parts of <i>Cassia</i><i>italica</i> Mill. (family: Fabaceae) growing in Saudi Arabia afforded one new cycloartane triterpene, named (22<i>E</i>)-3-β<i>-</i>hydroxycycloart-22-en-24-one (<b>2</b>), together with eight known compounds: β-sitosterol (<b>1</b>), uvaol (<b>3</b>), daucosterol (<b>4</b>), methyl 3,4-dihydroxybenzoate (<b>5</b>), emodin (<b>6</b>), 4-hydroxypheny-<i>O</i>-β-D-glucopyranoside (<b>7</b>), aloin (<b>8</b>) and rutin (<b>9</b>). The structure of the isolated compounds was determined by physical, chemical and spectral data (UV, IR, MS, 1D (¹H, ¹³C and DEPT) and 2D (¹H–¹H COSY, HSQC and HMBC) NMR), as well as by comparing with authentic samples. Compounds <b>3</b>–<b>5</b> and <b>7</b>–<b>9</b> were isolated for the first time from the plant. Compound <b>2</b> was evaluated for its cytotoxic activity against the L5178Y and PC12 cell lines. The total methanolic extract and compounds <b>5</b>–<b>9</b> exhibited free radical-scavenging activity using DPPH assay.</p></div

Natural occurring 2-(2-phenylethyl) chromones, structure elucidation and biological activities

<div><p>2-(2-Phenylethyl) chromone (PEC), an uncommon class of chromones, possesses a phenylethyl substituent at the C2 position. They have been isolated from a few plant species. They have promising biological activities such as neuro-protective, cytotoxic, acetylcholinesterase inhibitory, antibacterial and anti-inflammatory. This review focuses on the naturally occurring PEC derivatives, their sources, physical and spectral data, as well as biological activities.</p></div

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

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

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

Alnuheptanoid A: a new diarylheptanoid derivative from <i>Alnus japonica</i>

<div><p>Extensive chromatographic investigation of the ethanolic extract of <i>Alnus japonica</i> Steud stem bark led to the isolation of a new diarylheptanoid named alnuheptanoid A [(5<i>S</i>)-7-(3,4-dihydroxyphenyl)-1-(4-hydroxyphenyl)-5-methoxyheptan-3-one] (<b>8</b>), together with seven known diarylheptanoid derivatives: platyphyllenone (<b>5</b>), (5<i>S</i>)-1,7-bis(4-hydroxyphenyl)-5-methoxyheptan-3-one (<b>6</b>), 1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-4-hepten-3-one (<b>7</b>), hirsutenone (<b>9</b>), (5<i>R</i>)-<i>O</i>-methylhirsutanonol (<b>10</b>), hirsutanonol (<b>11</b>) and oregonin (<b>13</b>), three triterpenes: α-amyrin (<b>1</b>), betulinaldehyde (<b>3</b>) and betulinic acid (<b>4</b>), and two sterols: β-sitosterol (<b>2</b>) and daucosterol (<b>12</b>). Compound <b>6</b> was isolated for the first time from natural source. The structures of the isolated compounds were determined on the basis of spectroscopic measurements (UV, IR, HR-ESI-MS, 1D and 2D NMR).</p></div

Urgineaglyceride A: a new monoacylglycerol from the Egyptian <i>Drimia maritima</i> bulbs

<div><p>One new compound, (2<i>S</i>)-1-<i>O</i>-(<i>Z</i>)-tetracos-6-enoate glycerol (<b>1</b>) named urgineaglyceride A, along with six known compounds, 3,5,7,3′,5′-pentahydroxydihydroflavonol (<b>2</b>), stigmasterol (<b>3</b>), (25<i>S</i>)-5β-furostane-3β-22α-26-triol (<b>4</b>), scillaridin A (<b>5</b>), (2<i>S</i>)-(+)-2-hydroxynaringenin-4′-<i>O</i>-β-d-glucopyranoside (<b>6</b>) and quercetin-3′-<i>O</i>-β-d-glucopyranoside (<b>7</b>), were isolated from the EtOAc fraction of <i>Drimia maritima</i> (L.) Stearn bulbs. Their structures were secured based on their IR, UV, 1D and 2D NMR data, in addition to HR-MS data and comparison with the literature data. The isolated compounds were evaluated for their <i>in vitro</i> growth inhibitory activity against A549 non-small cell lung cancer (NSCLC), U373 glioblastoma (GBM) and PC-3 prostate cancer cell lines. Compounds <b>2</b> and <b>3</b> displayed variable activities against the tested cancer cell lines. Compound <b>2</b> was a selective inhibitor of the NSCLC cell line with an IC₅₀ of 2.3 μM, whereas <b>3</b> was selective against GBM with IC₅₀ of 0.5 μM and against PC-3 with 2.0 μM.</p></div

Didemnacerides A and B: two new glycerides from Red Sea ascidian <i>Didemnum</i> species

<div><p>Two new glycerides, didemnacerides A (<b>1</b>) and B (<b>2</b>), together with three known sterols, 24-ethyl-25-hydroxycholesterol (<b>3</b>), cholest-6-en-3,5,8-triol (<b>4</b>) and cholestane-3β,5α,6β-26-tetrol (<b>5</b>), were isolated from the Red Sea ascidian <i>Didemnum</i> sp. Their structures were elucidated by using extensive 1D (¹H, ¹³C) and 2D (¹H–¹H COSY, HSQC and HMBC) NMR studies and mass spectroscopic data (GC-MS and HR-MS) as well as alkaline hydrolysis followed by GC–MS and NMR spectral analyses of the fatty acid methyl esters. This is the first report of compounds <b>3</b>–<b>5</b> from the Red Sea ascidian <i>Didemnum</i> species.</p></div

Mangostanaxanthone VIII, a new xanthone from <i>Garcinia mangostana</i> and its cytotoxic activity

<p>A new prenylated xanthone, mangostanaxanthone VIII (<b>7</b>) and six known metabolites: gartanin (<b>1</b>), 1,3,8-trihydroxy-2-(3-methyl-2-butenyl)-4-(3-hydroxy-3-methylbutanoyl)-xanthone (<b>2</b>), rubraxanthone (<b>3</b>), 1,3,6,7-tetrahydroxy-8-prenylxanthone (<b>4</b>), garcinone C (<b>5</b>), and xanthone I (9-hydroxycalabaxanthone) (<b>6</b>) were separated from the EtOAc-soluble fraction of the air-dried pericarps of <i>Garcinia mangostana</i> (Clusiaceae). Their structures have been verified on the basis of spectroscopic data analysis as well as comparison with the literature. The cytotoxic activity of <b>7</b> was assessed against MCF7, A549, and HCT116 cell lines using sulforhodamine B (SRB) assay. Compound <b>7</b> showed significant cytotoxic potential against MCF7 and A549 cell lines with IC₅₀s 3.01 and 1.96 μM, respectively compared to doxorubicin (0.06 and 0.44 μM, respectively). However, it exhibited moderate activity towards HCT116 cell line.</p

New fatty acids from the Red Sea sponge <i>Mycale euplectellioides</i>

<div><p>Chemical investigation of the Red Sea sponge <i>Mycale euplectellioides</i> afforded two new compounds; hexacosa-(6<i>Z</i>,10<i>Z</i>)-dienoic acid methyl ester (<b>1</b>) and hexacosa-(6<i>Z</i>,10<i>Z</i>)-dienoic acid (<b>2</b>), along with two known compounds: icosa-(8<i>Z</i>,11<i>Z</i>)-dienoic acid methyl ester (<b>3</b>) and β-sitosterol (<b>4</b>). The structures were elucidated by the interpretation of their spectral data. The total methanol extract (TME) of the sponge exhibited potent antimicrobial activity against the different strains at a concentration of 100 mg/mL. All tested fractions did not exhibit any activity against <i>Serratia marcescens</i> and tested fungal strains. The TME and different fractions displayed anti-inflammatory and antipyretic activities at doses of 100 and 200 mg/kg compared with indomethacin (8 mg). The TME exhibited a remarkable hepato-protective effect in CCl₄-induced liver damage compared with silymarin. Furthermore, compounds <b>1</b> and <b>2</b> displayed weak activity against A549 non-small cell lung cancer, the U373 glioblastoma and the PC-3 prostate cancer cell lines.</p></div