Search

A detailed chemical investigation of the Sanya Bay nudibranch Hexabranchus sanguineus yielded thirteen new sesquiterpenoids, namely sanyagunins A-H, sanyalides A-C, and sanyalactams A and B, along with eleven known related ones. Sanyalactams A and B feature an unprecedented hexahydrospiro[indene-2,3'-pyrrolidine] core. The structures of new compounds were established by a combination of extensive spectroscopic data analysis, quantum mechanical-nuclear magnetic resonance methods, the modified Mosher's method, and X-ray diffraction analysis. Based on analysis of NOESY correlations and the modified Mosher's method, the stereochemistry of two known furodysinane-type sesquiterpenoids were revised. A plausible biogenetic relationship between these sesquiterpenoids wasproposed and discussed, and a chemo-ecological relationship of the title animal and its possible sponge preys has been analyzed. In bioassays, sanyagunin B showed moderate antibacterial activity, whereas 4α-formamidogorgon-11-ene exhibited potent cytotoxicity with IC 50 values ranging from 0.87 to 1.95 μM., (© 2023 Wiley-VCH GmbH.)

Chemical investigation of the Hainan soft coral Sinularia hirta resulted in the isolation and identification of a library of sixteen structurally diverse terpenoids, including a dinorditerpenoid with an uncommon 17,19-dinorxeniaphyllane skeleton, namely sinuhirtone A ( 7 ), six new xeniaphyllane-type diterpenoids ( 1 - 6 ), one new norxeniaphyllanoid ( 8 ), two new norcaryophyllene-type sesquiterpenoids ( 9 and 10 ), together with six known related compounds ( 11 - 16 ). Compounds 1 - 3 are three new furanone-containing xeniaphyllane-type diterpenoids. The structures of the new compounds, including their absolute configurations, were determined by extensive spectroscopic analysis and a series of quantum chemical calculations, including quantum mechanical-nuclear magnetic resonance (QM-NMR), time-dependent density functional theory-electronic circular dichroism (TDDFT-ECD), and optical rotatory dispersion (ORD) methods. A plausible biosynthetic connection between new compounds 1 - 9 was also proposed. New compounds 2 - 4 , 7 , and 8 were evaluated for in vitro cytotoxicity against four cancer cell lines.

A detailed chemical investigation of two South China Sea nudibranchs Phyllidiella pustulosa and Phyllidia coelestis , as well as their possible sponge-prey Acanthella cavernosa , led to the isolation of one new nitrogenous cadinane-type sesquiterpenoid xidaoisocyanate A ( 1 ), one new naturally occurring nitrogen-containing kalihinane-type diterpenoid bisformamidokalihinol A ( 16 ), along with 17 known nitrogenous terpenoids ( 2 ⁻ 15 , 17 ⁻ 19 ). The structures of all the isolates were elucidated by detailed spectroscopic analysis and by the comparison of their spectroscopic data with those reported in the literature. In addition, the absolute stereochemistry of the previously reported axiriabiline A ( 5 ) was determined by X-ray diffraction (XRD) analysis. In a bioassay, the bisabolane-type sesquiterpenoids 8 , 10 , and 11 exhibited cytotoxicity against several human cancer cell lines.

Three novel heterodimeric laurane-type sesquiterpenoids, laurokamurols A-C (1-3), along with eight known related monomeric ones (4-11) were isolated from the East China Sea red alga Laurencia okamurai Yamada. The absolute configurations of the new bis-sesquitepenoids, especially their axial chirality, were determined by extensive spectroscopic analyses and TDDFT-ECD method. All of the new compounds showed promising PTP1B inhibitory activities with IC 50 values comparable to the positive control, indicating them as potential food additives or pharmaceutical drug leads toward obesity or diabetes.

Two new laurane-type sesquiterpenoids, debromo-3α-hydroperoxy-3-epiaplysin (1) and debromo-3β-hydroperoxyaplysin (2), together with seven known related compounds (3-9), were isolated from the Chinese red alga Laurencia okamurai. Their structures were elucidated by detailed analysis of spectroscopic data and by comparison with the literature. In bioassay, compounds 2, 4, 8, and 9 exhibited significant PTP1B inhibitory activity with IC50 values ranging from 4.9 to 14.9 μg/ml.

Four new (1-4) and 13 known (5-17) sesquiterpene lactones along with two known diterpenes (18, 19) were isolated from the whole plant of Carpesium faberi. The new structures were elucidated by means of spectroscopic techniques and some chemical transformations to be pseudoguaian-1α(H)-8α,12-olide-4β-O-β-d-glucopyranoside (1), 4β,10α-dihydroxy-5α(H)-1,11(13)-guaidien-8α,12-olide (2), 4β,10β-dihydroxy-5α(H)-1, 11(13)-guaidien-8β,12-olide (3), and (4S)-acetyloxyl-11(13)-carabren-8β,12-olide (4). All isolates were tested against MCF-7 human breast cancer cells using the MTT assay. Among them, the sesquiterpene lactones (except tomentosin 17) possessing an α-methylene-γ-lactone moiety were found to have in vitro antiproliferative activities, with IC(50) values of 3.0-38.8μg/mL. The effects of four selected sesquiterpene lactones (guaianolide 2, carabranolide 4, pseudoguaianolide 9, eudesmanolide 13) on the cell cycle were examined using flow cytometry (FCM)., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

A detailed chemical investigation of the Sanya Bay nudibranch Hexabranchus sanguineus yielded thirteen new sesquiterpenoids, namely sanyagunins A−H, sanyalides A−C, and sanyalactams A and B, along with eleven known related ones. Sanyalactams A and B feature an unprecedented hexahydrospiro[indene‐2,3′‐pyrrolidine] core. The structures of new compounds were established by a combination of extensive spectroscopic data analysis, quantum mechanical‐nuclear magnetic resonance methods, the modified Mosher's method, and X‐ray diffraction analysis. Based on analysis of NOESY correlations and the modified Mosher's method, the stereochemistry of two known furodysinane‐type sesquiterpenoids were revised. A plausible biogenetic relationship between these sesquiterpenoids wasproposed and discussed, and a chemo‐ecological relationship of the title animal and its possible sponge preys has been analyzed. In bioassays, sanyagunin B showed moderate antibacterial activity, whereas 4α‐formamidogorgon‐11‐ene exhibited potent cytotoxicity with IC50 values ranging from 0.87 to 1.95 μM. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A detailed chemical investigation of the South China Sea nudibranch Hexabranchus sanguineus, as well as its possible sponge‐prey Acanthella cavernosa, led to the isolation of fifteen new nitrogenous sesquiterpenoids, namely ximaocavernosins A−O, including seven cadinanes (1—7), seven spiroaxanes (12—18) and one aromadendrane (19), together with thirteen known related compounds (8—11 and 20—28). Compounds (±)‐1—9 (except for 4 and 6) were further separated by chiral‐phase HPLC to their corresponding unequal enantiomers, respectively. Their structures and absolute configurations were determined by a combination of extensive spectroscopic data analysis, quantum mechanical nuclear magnetic resonance (QM‐NMR) methods, Mosher's method, X‐ray diffraction analysis and/or time‐dependent density functional theory/electronic circular dichroism (TDDFT‐ECD) calculation. The commonly existed nitrogenous sesquiterpenoids in these two animals are suggested to be chemical markers for their prey‐predator relationship. [ABSTRACT FROM AUTHOR]

Four new uncommon nitrogenous eudesmane-type sesquiterpenes, axiriabilines A−D ( 1 – 4 ), and two known related ones ( 5 and 6 ), were isolated from the Hainan sponge Axinyssa variabilis . The structures of the new compounds were elucidated on the basis of extensive spectroscopic analysis and by comparison of their NMR data with those reported in the literature. The absolute configurations of compounds 1 and 4 were determined by TDDFT ECD calculations. All the new compounds were found to exhibit no cytotoxicity against several cancer cells. [ABSTRACT FROM AUTHOR]

Two new highly oxidized formamidobisabolene sesquiterpenes ( 1 and 2), together with seven known related analogues ( 3 - 9), were isolated from a Hainan sponge Axinyssa variabilis. Their structures were determined by extensive 1D- and 2D- NMR and MS spectra analyses, and by comparison of their spectroscopic data with those of the related model compounds. The plausible biosynthetic relationship between compounds 1 - 9 has also been described. [ABSTRACT FROM AUTHOR]

Chemical study of a Hainan sponge Halichondria sp. resulted in the isolation of eight new formamidobisabolene-based sesquiterpenes halichines A–E (1 – 3 , 7 , 8), ent-axinyssine G [(−)- 4 ], ent-axinyssine J [(−)- 5 ], and ent-axinyssine K [(−)- 6 ], along with five related known ones [(+)- 4 , (+)- 5 , (+)- 6 , 10 , 11 ]. Their structures were determined on the basis of extensive spectroscopic analyses, and the absolute configuration of halichine A (1) was determined by Snatzke's method. In bioassay, compounds 3 and 7 displayed considerable anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated BV-2 microglia cells. [Display omitted] • Eight new nitrogenous sesquiterpenes were isolated from the Hainan sponge Halichondria sp. • Snatzke's method was used for the assignment of absolute configurations of 1. • 3 and 7 displayed considerable anti-inflammatory activity in LPS-stimulated BV-2 cells. [ABSTRACT FROM AUTHOR]

isolation and structure determination [ABSTRACT FROM AUTHOR]