Search

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]

The complete mitochondrial genome (mitogenome) of the soft coral Sinularia acuta Manuputty and van Ofwegen, 2007 was sequenced and annotated using Illumina next-generation sequencing (NGS). The mitogenome of S. acuta was 18,730 bp in length and consisted of 14 protein-coding genes (PCGs), two ribosomal RNA genes (rRNA), and only one transfer RNA gene (tRNA-Met). The base composition was 30.18% A, 16.46% C, 19.35% G, and 34.00% T, with a total A + T content of 64.19%. The phylogenetic analysis demonstrated a close evolutionary relationship among Sinularia acuta, Sinularia penghuensis, and Sinularia maxima.

Nanolobatone A, featuring an unprecedented tricyclo[10.3.0.01,2]pentadecane carbon skeleton, along with four new polyoxygenated and four unusual endoperoxide‐bridged casbane‐type diterpenoids were isolated from the Hainan soft coral Sinularia nanolobata. The structures of the new compounds were established by extensive spectroscopic analysis, X‐ray diffraction analysis, and time‐dependent density functional theory/electronic circular dichroism calculations. A plausible biosynthetic pathway of new isolates was proposed. Bioassays revealed that nanolobatone A showed weak antibacterial activity against the Gram‐positive bacteria Streptococcus pyogenes. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome (mitogenome) of the soft coral Sinularia acuta Manuputty and van Ofwegen, 2007 was sequenced and annotated using Illumina next-generation sequencing (NGS). The mitogenome of S. acuta was 18,730 bp in length and consisted of 14 protein-coding genes (PCGs), two ribosomal RNA genes (rRNA), and only one transfer RNA gene (tRNA-Met). The base composition was 30.18% A, 16.46% C, 19.35% G, and 34.00% T, with a total A + T content of 64.19%. The phylogenetic analysis demonstrated a close evolutionary relationship among Sinularia acuta, Sinularia penghuensis, and Sinularia maxima. [ABSTRACT FROM AUTHOR]

Soft corals are zooxanthellate sessile animals supporting various organisms in coral reefs. However, their populations are threatened by the impacts of ocean warming. Under thermal stress conditions, soft corals may experience mild to severe bleaching which may lead to death. Understanding soft coral bleaching responses highlights the importance in predicting how populations and diversity may be affected by changing climate scenarios. In this study, we examined the bleaching responses of the three dominant soft coral genera (Lobophytum, n = 1318; Sarcophyton, n = 116; Sinularia, n = 639 colonies) in the Bolinao-Anda Reef Complex (BARC), Pangasinan, north-western Philippines during the 2020 thermal stress event in terms of genus and colony size susceptibility, and zooxanthellae density. Degree heating week (DHW) data from 1986–2020 were obtained using remotely sensed data to determine thermal anomalies in the study sites. The maximum DHW (6.3) in 2020 occurred between July–August while bleaching surveys were done during October of the same year. The percentage of bleached portions in each colony was used to determine bleaching category: no bleaching (0%), moderately bleached (1–50%) and heavily bleached (>50%). Quantification of bleaching prevalence and susceptibility of colony sizes were determined by colony count and mean diameter measurements taken from quadrat photographs in October 2020. Haphazard tissue collection (∼3 cm) in each colony of three soft coral genera per bleaching category was done to quantify zooxanthellae density. Results showed that Lobophytum colonies had the lowest bleaching prevalence (41%), followed by Sinularia (66%) and Sarcophyton (78%). All colony size classes of the three genera were susceptible to bleaching. However, smaller colonies of Lobophytum (<15 cm), Sarcophyton (<5 cm) and Sinularia (<5 cm) showed less susceptibility than large colonies. Zooxanthellae density was significantly reduced in moderately and heavily bleached colonies. The results of this study highlight that bleaching susceptibility is genus specific, with Sarcophyton and Sinularia being more susceptible to bleaching than Lobophytum. Smaller colonies seemed to be less susceptible to bleaching than large-sized soft corals suggesting a differential thermal stress response. Spatial variations in bleaching prevalence were also found among reef sites with varying environmental conditions and thermal stress histories. This work provided initial observations on how bleaching affects soft corals. Further studies on soft coral community recovery are recommended to fully understand how these organisms perform after thermal stress events. [ABSTRACT FROM AUTHOR]

Extending our knowledge about the bleaching and recovery processes in octocorals can offer valuable insights to predict future reef responses to continuing climate change. The octocoral Sinularia heterospiculata was exposed to a heat stress (32°C) for 2 days and then recovered within 205 days. The coral's response was assessed by measuring total lipids, chlorophylls , carotenoids, and relative endosymbiont density. During the bleaching period, the coral lost half of its dinoflagellate symbionts; during the recovery period, it could completely restore their population. Photosynthetic activity of dinoflagellate symbionts was reduced after 1 week of recovery. However, the level of lipids was stable. The contents of chlorophyll b after the 2-day bleaching period increased relative to their proportion in the endosymbionts, which may be associated with the chlorophyll repackaging and absorption of more light. The content of carotenoids increases, which is probably associated with the complementary function of carotenoids as antioxidants. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome (mitogenome) of the soft coral Sinularia acuta Manuputty and van Ofwegen, 2007 was sequenced and annotated using Illumina next-generation sequencing (NGS). The mitogenome of S. acuta was 18,730 bp in length and consisted of 14 protein-coding genes (PCGs), two ribosomal RNA genes (rRNA), and only one transfer RNA gene ( tRNA-Met ). The base composition was 30.18% A, 16.46% C, 19.35% G, and 34.00% T, with a total A + T content of 64.19%. The phylogenetic analysis demonstrated a close evolutionary relationship among Sinularia acuta , Sinularia penghuensis , and Sinularia maxima ., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)

Two novel chlorine-containing cembranoids, chlorofurancembranoids A (1) and B (2), were isolated from an octocoral identified as Sinularia sp. The structures of 1 and 2 were elucidated using spectroscopic methods, and the absolute configuration of 1 was further confirmed by single-crystal X-ray diffraction analysis. Cembranoid 2 showed cytotoxicity towards human promyelocytic leukemia HL-60 cells, with an IC 50 value of 3.67 μM. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] A novel cembranoid, (1 R ,7 R ,8 R ,11 R ,12 R)-7,8:11,12-bisepoxycembrene A (1), was isolated from an octocoral Sinularia sp. The structure of 1 was elucidated using spectroscopic methods, and its absolute configuration was confirmed by a single-crystal X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

Marine organisms are recognized as a rich source of bioactive secondary metabolites. The remarkable abundance and diversity of bioactive small molecules isolated from soft corals displayed their essential role in drug discovery for human diseases. Sterols and terpenes, particularly cembranolides, 14-membered cyclic diterpene, demonstrated numerous biological activities, such as antitumor, antimicrobial, antiviral, antidiabetic, anti-osteoporosis and anti-inflammatory. Accordingly, continuous investigation of marine soft corals leads the way to discover a plentiful number of chemical diverse natural products with various biological potentials for prospective pharmaceutical industrial applications. Such review affords plenary inspection of the total secondary metabolites isolated from the Sinularia, from 2008 until 2020, besides their natural sources as well as bioactivities whenever possible., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)