Quantum Mechanical–NMR-Aided Configuration and Conformation of Two Unreported Macrocycles Isolated from the Soft Coral <i>Lobophytum</i> sp.: Energy Calculations versus Coupling Constants

Li, Song-Wei; Cuadrado, Cristina; Yao, Li‐Gong; Daranas, Antonio Hernández; Guo, Yue‐Wei

doi:10.1021/acs.orglett.0c01155

Cited by 55 publications

(37 citation statements)

References 26 publications

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“…As a proof of principle this is demonstrated here (see Figure 5) for a cyclic peptide PGLGF, [54] and the two natural products lobophytolins A [56] and (À )-dactylolide. [57] The Figure 3.…”

Section: Zuschriftensupporting

confidence: 56%

Hydrocarbon Macrocycle Conformer Ensembles and ¹³C‐NMR Spectra

Bohle

Grimme

2022

Angewandte Chemie

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NMR as a routine analytical method provides important three-dimensional structure information of compounds in solution. Here we apply the recently released CRENSO computational workflow for the automated generation of conformer ensembles to the quantum mechanical calculation of 13 C-NMR spectra of a series of flexible cycloalkanes up to C 20 H 40 . We evaluate the computed chemical shifts in comparison with corresponding experimental data in chloroform. It is shown that accurate and properly averaged theoretical NMR data can be obtained in about a day of computation time on a standard workstation computer. The excellent agreement between theory and experiment enables one to deduce preferred conformations of large, non-rigid macrocycles under ambient conditions from our automated procedure.

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Section: Zuschriftensupporting

confidence: 56%

Hydrocarbon Macrocycle Conformer Ensembles and ¹³C‐NMR Spectra

Bohle

Grimme

2022

Angewandte Chemie

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“…Considering the flexibility of these macrocycles and their variable/unstable conformation, to assign the correct relative configuration based on conventional dipolar correlations extracted from NOESY experiments is somewhat risky and a challenging task. [ 19 ] So, it is not surprising that several erroneous structures are continually being detected and revised. [ 17,20‐22 ] Hence, there has been a growing interest in re‐examining and determining the absolute configuration of the known compounds.…”

Section: Resultsmentioning

confidence: 99%

Polyoxygenated Cembranoids from Soft Coral Lobophytum Crassum and Their Anti‐tumoral Activities

et al. 2021

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Main observation and conclusion Four new cembranoids, 6‐oxo‐cembrene‐A (1), lobocrassins G—H (2—3), and 14‐epi‐lobophytolide B (4), along with eight known related compounds (5—12), were isolated from the South China Sea soft coral Lobophytum crassum. Their structures were established by extensive spectroscopic analysis and by comparison of the spectral data with those reported in the literatures. The absolute stereochemistry of 14‐epi‐lobophytolide B (4) was established by time‐dependent density functional theory electronic circular dichroism (TDDFT‐ECD) calculations, whereas that of three known metabolites (6, 11 and 12) was also determined, for the first time, by using modified Mosher's method and/or X‐ray diffraction analyses. In bioassay, the cembranoids 6, 7 and 12 showed significant anti‐tumoral activity against A549, HT‐29, SNU‐398 and Capan‐1 tumor cell lines with IC50 values ranging from 1.5 to 7.4 μmol/L. A preliminary structure‐activity relationship was also discussed.

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“… Off the coast of Xisha Islands, Hainan Province Inactive at a concentration of 10 µM, on the HT-29, Capan-1, A549, and SNU-398 tumor cell lines (showed IC 50 > 50 µM) [ 71 ] 48 Lobophytolin B ( 269 ) New Lobophytum sp. Off the coast of Xisha Islands, Hainan Province Inactive at a concentration of 10 µM, on the HT-29, Capan-1, A549, and SNU-398 tumor cell lines (IC 50 values ranging from 30 to 40 µM) [ 71 ] 49 Lobophytolin C ( 270 ) New Lobophytum sp. Xisha Island, Hainan, China Moderate cytotoxicity against SNU-398 with IC 50 value of 42.54 ± 6.26 μM; weak inhibitory effect of XBP-Splicing on B16-F10 tumor cells at 10 μM [ 72 ] 50 Lobophytolin D ( 271 ) New Lobophytum sp.…”

Section: Cembranoidsmentioning

confidence: 99%

“…Lastly, new macrocyclic cembranoids lobophytolins A-B 268–269 isolated from Lobophytum sp. were collected from Xisha Islands, China, with both compounds not showing any biological activities [ 71 ]. Lastly, seven unreported cembranoid was isolated from Lobophytum sp.…”

Section: Cembranoidsmentioning

confidence: 99%

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Cembranoids of Soft Corals: Recent Updates and Their Biological Activities

Nurrachma

Sakaraga

Nugraha

et al. 2021

Nat. Prod. Bioprospect.

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Soft corals are well-known as excellent sources of marine-derived natural products. Among them, members of the genera Sarcophyton, Sinularia, and Lobophytum are especially attractive targets for marine natural product research. In this review, we reported the marine-derived natural products called cembranoids isolated from soft corals, including the genera Sarcophyton, Sinularia, and Lobophytum. Here, we reviewed 72 reports published between 2016 and 2020, comprising 360 compounds, of which 260 are new compounds and 100 are previously known compounds with newly recognized activities. The novelty of the organic molecules and their relevant biological activities, delivered by the year of publication, are presented. Among the genera presented in this report, Sarcophyton spp. produce the most cembranoid diterpenes; thus, they are considered as the most important soft corals for marine natural product research. Cembranoids display diverse biological activities, including anti-cancer, anti-bacterial, and anti-inflammatory. As cembranoids have been credited with a broad range of biological activities, they present a huge potential for the development of various drugs with potential health and ecological benefits. Graphic Abstract

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Quantum Mechanical–NMR-Aided Configuration and Conformation of Two Unreported Macrocycles Isolated from the Soft Coral Lobophytum sp.: Energy Calculations versus Coupling Constants

Cited by 55 publications

References 26 publications

Hydrocarbon Macrocycle Conformer Ensembles and ¹³C‐NMR Spectra

Hydrocarbon Macrocycle Conformer Ensembles and ¹³C‐NMR Spectra

Polyoxygenated Cembranoids from Soft Coral Lobophytum Crassum and Their Anti‐tumoral Activities

Cembranoids of Soft Corals: Recent Updates and Their Biological Activities

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Quantum Mechanical–NMR-Aided Configuration and Conformation of Two Unreported Macrocycles Isolated from the Soft Coral Lobophytum sp.: Energy Calculations versus Coupling Constants

Cited by 55 publications

References 26 publications

Hydrocarbon Macrocycle Conformer Ensembles and 13C‐NMR Spectra

Hydrocarbon Macrocycle Conformer Ensembles and 13C‐NMR Spectra

Polyoxygenated Cembranoids from Soft Coral Lobophytum Crassum and Their Anti‐tumoral Activities

Cembranoids of Soft Corals: Recent Updates and Their Biological Activities

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Product

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Hydrocarbon Macrocycle Conformer Ensembles and ¹³C‐NMR Spectra

Hydrocarbon Macrocycle Conformer Ensembles and ¹³C‐NMR Spectra