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The detailed chemical investigations of the South China Sea soft corals Sinularia tumulosa and Sinularia depressa, yielded two new compounds, namely tumulosterol A (1) and 11'-hydroxy-α-tocopherylquinone (3), along with four related known ones (2, 5–7). Their structures were determined by extensive spectroscopic analysis and comparison with the spectral data previously reported in the literature. In bioassays, compound 1 displayed significant cytotoxic effects against H1975 and MDA-MB-231 cells with IC50 values of 6.0 and 6.3 µM, respectively. In addition, compound 3 exhibited interesting inhibitory effect on lipopolysaccharide (LPS)-induced inflammatory responses in RAW264.7 cells with IC50 value of 9.5 µM. [ABSTRACT FROM AUTHOR]

Three new cembranoids (1–3) and a new casbanoid (4), along with three known analogues (5–7), have been isolated from the soft coral Sinularia nanolobata collected off Ximao Island. The structures, including the absolute configurations of new compounds, were established using extensive spectroscopic data analysis, time-dependent density functional theory/electronic circular dichroism (TDDFT-ECD) calculations, and the comparison with spectroscopic data of known compounds. In the in vitro bioassay, compounds 1 and 5 exhibited moderate cytotoxic activities against human erythroleukemia (HEL) cell lines, with IC50 values of 37.1 and 42.4 μM, respectively. [ABSTRACT FROM AUTHOR]

A new bis-γ-pyrone polypropionate, 4,16-di-epi-onchidiol (1), along with three known related compounds (2–4) were isolated from the marine pulmonate mollusk Onchidium sp. The structure of compound 1 was elucidated by extensive spectroscopic analysis and by comparison the NMR data with its stereoisomers 2–4, whereas its absolute configuration was determined by the combination of X-ray diffraction analysis and TDDFT-ECD calculation. In bioassay, the isolated compounds exhibited broad cytotoxicity against several cancer cell lines with IC50 values ranging from 24.6 to 88.5μM. [ABSTRACT FROM AUTHOR]

Two new steroids, ximaosteroid E ( 1 ) and ximaosteroid F ( 2 ), along with two known related compounds ( 3 and 4 ), were isolated from the Chinese soft coral Sinularia sp . Notably, 1 possesses an uncommon dihydrofuran group. Their structures were established from extensive spectroscopic analyses and comparisons of their spectral data with those reported in the literature. The absolute configuration of 2 was determined by applying the modified Mosher’s method. In bioassay, compounds 1 , 2 , and 4 showed significant cytotoxicity against the HL-60 tumor cell line with IC 50 values of 1.79, 4.03 and 0.69 μM, respectively. [ABSTRACT FROM AUTHOR]

• This was the first chemical study of soft coral Litophyton nigrum. • Nardosinanes and neolemnanes were firstly reported from the genus Litophyton. • Mosher's method, TDDFT-ECD and X-Ray analysis were used to determine absolute configurations. • Cytotoxic and inhibitory activities of protein kinases were evaluated. Three new nardosinane-type sesquiterpenoids linardosinenes A–C (1 – 3) and four new neolemnane-type sesquiterpenoids lineolemnenes A–D (4 – 7), together with the related known compound 4-acetoxy-2,8-neolemnadien-5-one (8), were isolated from the Xisha soft coral Litophyton nigrum. The structures of these new compounds were elucidated by comprehensive analyses of spectroscopic data, in association with modified Mosher's method and ECD calculations for configurational assignments and the absolute configuration of 8 was determined by X-ray diffraction analysis for the first time. Structurally uncommon nornardosinane and seconeolemnane skeletons for compounds 1 and 7 , respectively, are rare carbon frameworks in naturally occurring sesquiterpenoids. The absolute configurations of 1 , 7 , and 8 were determined by modified Mosher's method, TDDFT ECD approach, and X-ray diffraction analysis, respectively. This is the first chemical study of L. nigrum and the first report of nornardosinane, seconeolemnane and related sesquiterpenoids from the genus Litophyton. The isolates 1 – 7 were evaluated for their cytotoxicity against THP-1, SNU-398, HT-29, Capan-1 and A549 cell lines and inhibitory activities against PTP1B, BRD4, HDAC1 and HDAC6 protein kinases. The results indicated that compounds 2 – 5 inhibited proliferation of human cancer cells. However, none of them were potent inhibitors of protein kinases. [ABSTRACT FROM AUTHOR]

Molecular networking strategy-based prioritization of the isolation of the rarely studied soft coral Sinularia tumulosa yielded 14 sesquiterpenes. These isolated constituents consisted of nine different types of carbon frameworks, namely asteriscane, humulane, capillosane, seco-asteriscane, guaiane, dumortane, cadinane, farnesane, and benzofarnesane. Among them, situmulosaols A–C (1 , 3 and 4) were previously undescribed ones, whose structures with absolute configurations were established by the combination of extensive spectral data analyses, quantum mechanical-nuclear magnetic resonance and time-dependent density functional theory electronic circular dichroism calculations, the Snatzke's method, and the modified Mosher's method. Notably, situmulosaol C (4) was the second member of capillosane-type sesquiterpenes. The plausible biogenetic relationships of these skeletally different sesquiterpenes were proposed. All sesquiterpenoids were evaluated for their antibacterial, cytotoxic and anti-inflammatory effects. The bioassay results showed compound 14 exhibited significant antibacterial activities against a variety of fish and human pathogenic bacteria with MIC 90 values ranging from 3.6 to 33.8 μg/mL. Moreover, moderate cytotoxic effects against HEL cells for components 13 and 14 and moderate inhibitory effect on lipopolysaccharide-induced inflammatory responses in RAW264.7 cells for substance 13 were also observed. [Display omitted] • 14 sesquiterpenes were isolated from Sinularia tumulosa applying molecular networking. • These isolates possessed nine different carbon frameworks. • Situmulosaol C (4) was the second member of capillosane-type sesquiterpenes. • Absolute configurations were assigned by QM-NMR, TDDFT ECD, ICD, and Mosher's method. • Compound 14 showed significant antibacterial and moderate cytotoxic activities. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

A phytochemical investigation of the fruits of Citrullus colocynthis resulted in the isolation of 21 structurally diverse cucurbitane triterpenoids, including 9 previously undescribed ones, colocynins A-I (1–9). Their absolute configurations were elucidated by means of quantum chemical electronic circular dichroism (ECD) calculations, CD exciton chirality method, and single-crystal X-ray crystallography. Colocynins A-C (1–3) represent the first examples of nonanorcucurbitane-type triterpenoids. An anti-acetylcholinesterase activity assay showed that 6 , 10 , 13 , 18 , and 20 exhibited inhibitory activities, with IC 50 values ranging from 5.0 to 21.7 μM. In addition, 18 and 21 showed significant cytotoxicity against PACA, A431, and HepG2 cells, with IC 50 values ranging from 0.042 to 0.60 and 3.6–14.4 μM, respectively. [Display omitted] • Nine new cucurbitane-type triterpenoids and twelve known analogues were isolated from the fruits of Citrullus colocynthis. • Compounds 1–3 represent the first examples of nonanorcucurbitane-type triterpenoids. • The absolute configurations of the new compounds were established. • Compounds 6 , 10 , 13 , 18 , and 20 exhibited anti-acetylcholinesterase activities. • Cytotoxic activities of compounds 18 and 21 are related to α , β -unsaturated conjugated system of C 17 side chain. [ABSTRACT FROM AUTHOR]