Alcina M M B Morais, Decha Kumla, Valter F R Martins, Ana Alves, Luis Gales, Artur M S Silva, Paulo M Costa, Sharad Mistry, Anake Kijjoa, Rui M S C Morais
{"title":"Monoterpene Hydroxy Lactones Isolated from <i>Thalassiosira</i> sp. Microalga and Their Antibacterial and Antioxidant Activities.","authors":"Alcina M M B Morais, Decha Kumla, Valter F R Martins, Ana Alves, Luis Gales, Artur M S Silva, Paulo M Costa, Sharad Mistry, Anake Kijjoa, Rui M S C Morais","doi":"10.3390/molecules29215175","DOIUrl":null,"url":null,"abstract":"<p><p>Two monoterpenoid lactones, loliolide (<b>1</b>) and <i>epi</i>-loliolide (<b>2</b>), were isolated from the crude dichloromethane extract of a microalga, <i>Thalassiosira</i> sp.). The structures of loliolide (<b>1</b>) and <i>epi</i>-loliolide (<b>2</b>) were elucidated by 1D and 2D NMR analysis, as well as a comparison of their <sup>1</sup>H or/and <sup>13</sup>C NMR data with those reported in the literature. In the case of loliolide (<b>1</b>), the absolute configurations of its stereogenic carbons were confirmed by X-ray analysis, whereas those of <i>epi</i>-loliolide (<b>2</b>) were determined by NOESY correlations. Loliolide (<b>1</b>) and <i>epi</i>-loliolide (<b>2</b>) were tested for their growth inhibitory activity against two Gram-positive (<i>Staphylococcus aureus</i> ATCC 29213, <i>Enterococcus faecalis</i> ATCC 29212) and two Gram-negative (<i>Escherichia coli</i> ATCC 25922, <i>Pseudomonas aeruginosa</i> ATCC 27853) bacteria, as well as one clinical isolate (<i>E. coli</i> SA/2, an extended-spectrum β-lactamase producer-ESBL) and two environmental isolates, <i>S. aureus</i> 74/24, a methicillin-resistant (MRSA), and <i>E. faecalis</i> B3/101, a vancomycin-resistant (VRE) isolates. The results showed that none of the tested compounds exhibited antibacterial activity at the highest concentrations tested (325 μM), and both revealed low antioxidant activity, with ORAC values of 2.786 ± 0.070 and 2.520 ± 0.319 µmol TE/100 mg for loliolide (<b>1</b>) and <i>epi</i>-loliolide (<b>2</b>), respectively.</p>","PeriodicalId":19041,"journal":{"name":"Molecules","volume":"29 21","pages":""},"PeriodicalIF":4.2000,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11547300/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Molecules","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.3390/molecules29215175","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Two monoterpenoid lactones, loliolide (1) and epi-loliolide (2), were isolated from the crude dichloromethane extract of a microalga, Thalassiosira sp.). The structures of loliolide (1) and epi-loliolide (2) were elucidated by 1D and 2D NMR analysis, as well as a comparison of their 1H or/and 13C NMR data with those reported in the literature. In the case of loliolide (1), the absolute configurations of its stereogenic carbons were confirmed by X-ray analysis, whereas those of epi-loliolide (2) were determined by NOESY correlations. Loliolide (1) and epi-loliolide (2) were tested for their growth inhibitory activity against two Gram-positive (Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212) and two Gram-negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853) bacteria, as well as one clinical isolate (E. coli SA/2, an extended-spectrum β-lactamase producer-ESBL) and two environmental isolates, S. aureus 74/24, a methicillin-resistant (MRSA), and E. faecalis B3/101, a vancomycin-resistant (VRE) isolates. The results showed that none of the tested compounds exhibited antibacterial activity at the highest concentrations tested (325 μM), and both revealed low antioxidant activity, with ORAC values of 2.786 ± 0.070 and 2.520 ± 0.319 µmol TE/100 mg for loliolide (1) and epi-loliolide (2), respectively.
期刊介绍:
Molecules (ISSN 1420-3049, CODEN: MOLEFW) is an open access journal of synthetic organic chemistry and natural product chemistry. All articles are peer-reviewed and published continously upon acceptance. Molecules is published by MDPI, Basel, Switzerland. Our aim is to encourage chemists to publish as much as possible their experimental detail, particularly synthetic procedures and characterization information. There is no restriction on the length of the experimental section. In addition, availability of compound samples is published and considered as important information. Authors are encouraged to register or deposit their chemical samples through the non-profit international organization Molecular Diversity Preservation International (MDPI). Molecules has been launched in 1996 to preserve and exploit molecular diversity of both, chemical information and chemical substances.