Marine Sponge Dactylospongia Elegans Research Articles

Unveiling the Efficacy of Sesquiterpenes from Marine Sponge Dactylospongia elegans in Inhibiting Dihydrofolate Reductase Using Docking and Molecular Dynamic Studies.

Dihydrofolate reductase (DHFR) is a crucial enzyme that maintains the levels of 5,6,7,8-tetrahydrofolate (THF) required for the biological synthesis of the building blocks of DNA, RNA, and proteins. Over-activation of DHFR results in the progression of multiple pathological conditions such as cancer, bacterial infection, and inflammation. Therefore, DHFR inhibition plays a major role in treating these illnesses. Sesquiterpenes of various types are prime metabolites derived from the marine sponge Dactylospongia elegans and have demonstrated antitumor, anti-inflammation, and antibacterial capacities. Here, we investigated the in silico potential inhibitory effects of 87 D. elegans metabolites on DHFR and predicted their ADMET properties. Compounds were prepared computationally for molecular docking into the selected crystal structure of DHFR (PDB: 1KMV). The docking scores of metabolites 34, 28, and 44 were the highest among this series (gscore values of -12.431, -11.502, and -10.62 kcal/mol, respectively), even above the co-crystallized inhibitor SRI-9662 score (-10.432 kcal/mol). The binding affinity and protein stability of these top three scored compounds were further estimated using molecular dynamic simulation. Compounds 34, 28, and 44 revealed high binding affinity to the enzyme and could be possible leads for DHFR inhibitors; however, further in vitro and in vivo investigations are required to validate their potential.

Thorectidiol A Isolated from the Marine Sponge Dactylospongia elegans Disrupts Interactions of the SARS-CoV-2 Spike Receptor Binding Domain with the Host ACE2 Receptor.

Thorectidiols isolated from the marine sponge Dactylospongia elegans (family Thorectidae, order Dictyoceratida) collected in Papua New Guinea are a family of symmetrical and unsymmetrical dimeric biphenyl meroterpenoid stereoisomers presumed to be products of oxidative phenol coupling of a co-occurring racemic monomer, thorectidol (3). One member of the family, thorectidiol A (1), has been isolated in its natural form, and its structure has been elucidated by analysis of NMR, MS, and ECD data. Acetylation of the sponge extract facilitated isolation of additional thorectidiol diacetate stereoisomers and the isolation of the racemic monomer thorectidol acetate (6). Racemic thorectidiol A (1) showed selective inhibition of the SARS-CoV-2 spike receptor binding domain (RBD) interaction with the host ACE2 receptor with an IC50 = 1.0 ± 0.7 μM.

Cytotoxic Sesquiterpenoid Quinones and Quinols, and an 11-Membered Heterocycle, Kauamide, from the Hawaiian Marine Sponge Dactylospongia elegans.

Several known sesquiterpenoid quinones and quinols (1–9), and kauamide (10), a new polyketide-peptide containing an 11-membered heterocycle, were isolated from the extracts of the Hawaiian marine sponge Dactylospongia elegans. The planar structure of 10 was determined from spectroscopic analyses, and its relative and absolute configurations were established from density functional theory (DFT) calculations of the GIAO NMR shielding tensors, and advanced Marfey’s analysis of the N-MeLeu residue, respectively. Compounds 1 and 3 showed moderate inhibition of β-secretase 1 (BACE1), whereas 1–9 exhibited moderate to potent inhibition of growth of human glioma (U251) cells. Compounds 1–2 and 4–7 were also active against human pancreatic carcinoma (Panc-1) cells.

Cytotoxic meroterpenoids from the marine sponge Dactylospongia elegans

Three new sesquiterpene quinones/hydroquinones, 20-demethoxy-20-isopentylaminodactyloquinone D (1), 20-demethoxy-20-isobutylaminodactyloquinone D (2), and 19-methoxy-dictyoceratin-A (3), and five known related compounds (4−8) were isolated from the marine sponge Dactylospongia elegans. Their structures were elucidated by spectroscopic analysis, ECD calculation, single-crystal X-ray diffraction, and comparison with the literature. Compounds 3 and 5−8 exhibited activities against the human cancer cell lines DU145, SW1990, Huh7, and PANC-1 with IC50 values ranging from 2.33 to 37.85 μM.

Two new steroids with cytotoxicity from the marine sponge Dactylospongia elegans collected from the South China Sea

A new steroid, (3S,5R,9R,10S,13R,17R,20R,24S,22E)-ergosta-6,8,22-triene-3,25-diol (1), and its sulfonated analogue (2) together with a known one, 5α,8α-epidioxy-cholest-6-en-3β-ol (3) were isolated from the marine sponge Dactylospongia elegans collected from the South China Sea. The new structures including absolute configurations were established by the HRESIMS and 1D and 2D NMR analysis coupled with the X-ray crystal analysis. Both of 1 and 2 exhibited cytotoxicity against cancer cell line MCF-7 with IC50 values of 9.7 and 8.5 μM, respectively.

Popolohuanones G - I, Dimeric Sesquiterpene Quinones with IL-6 Inhibitory Activity from the Marine Sponge Dactylospongia elegans.

Chemical investigation of the marine sponge Dactylospongia elegans, collected from the South China Sea, afforded three new dimeric sesquiterpene quinones, popolohuanones G - I (1 - 3), together with two known analogs, popolohuanones B (4) and C (5). The new structures were determined by HR-ESI-MS and 1D- and 2D-NMR analyses. All the five compounds showed no cytotoxic activity against five human cancer cell lines, while popolohuanone H (2) showed potent inhibitory activity against IL-6, an inflammatory cytokine, at the concentration of 10 μm.

New diterpenoids from the marine sponge Dactylospongia elegans

Eleganstone A (1), a rare diterpene possessing a 5/6/4/5 fused tetracyclic ring skeleton, along with its probable biogenetic precursor (2), one new dolabellane diterpene (3), and one known dolabellane diterpene (4), have been isolated from the marine sponge Dactylospongia elegans. As a pair of Z/E isomers, 2 can convert into 4 by the light-induced isomerization. Structure elucidations of all compounds were performed by spectroscopic analysis, ECD calculations, and comparison with the literature. These compounds were tested for their antibacterial and cytotoxic activities. Compounds 1–4 exhibited weak antibacterial activity against Escherichisa coli, Bacillus subtilis, and Staphylococcus aureus with MIC values of 32–64 μg/mL.

Cytotoxic drimane meroterpenoids from the Indonesian marine sponge Dactylospongia elegans

Chemical investigation of the methanol extract of an Indonesian marine sponge Dactylospongia elegans (family Thorectidae) afforded two undescribed drimane meroterpenoidal metabolites, dactylospongenones G and H (1 and 2) together with thirteen known compounds (3–15) including pelorol, 5-epi-ilimaquinone, 5-epi-smenospongine, 5-epi-smenospongidine, nakijiquinone D, smenospongine C, isospongiaquinone, isosmenospongine, nakijiquinones A-C, G and 5-epi-nakijiquinone Q. The structures of the new metabolites were unambiguously determined by 1D and 2D NMR spectroscopy and by HRESIMS. All isolated compounds were assessed for their antimicrobial, antitubercular and cytotoxic activities. Several tested compounds revealed significant cytotoxic activity against the mouse lymphoma L5178Y cell line with IC50 values ranging from 1.3 to 6.5μM. In antimicrobial and antitubercular activity assays some of the tested compounds exhibited potent activity with MIC values between 3.0 and 25.0μM.

Antiproliferative and Antiangiogenic Activities of Smenospongine, a Marine Sponge Sesquiterpene Aminoquinone

We previously reported that smenospongine, a sesquiterpene aminoquinone isolated from the marine sponge Dactylospongia elegans, showed antiproliferative or cytotoxic activities on leukemia cells. In this study, we investigated the effect of smenospongine on solid tumors. Since angiogenesis is well known to be closely involved in growth and metastasis of solid tumors, the antiangiogenic effect of smenospongine was determined. We found that smenospongine inhibited proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVEC). Moreover, the inhibitory activity of smenospongine on growth of solid tumor cells was investigated. Smenospongine inhibited the growth of 39 human solid cancer cells in vitro, with a mean Log GI50 value of −5.55. In conclusion, smenospongine exhibits antitumor activity on solid tumors via two mechanisms, an antiangiogenic effect on endothelial cells and direct inhibition of growth of tumor cells.

Sesquiterpene Benzoxazoles and Sesquiterpene Quinones from the Marine Sponge Dactylospongia elegans

A new sesquiterpene benzoxazole, nakijinol B (3), its acetylated derivative, nakijinol B diacetate (6), and two new sesquiterpene quinones, smenospongines B (4) and C (5), were isolated from the methanol extract of the marine sponge Dactylospongia elegans. Also isolated were the known compounds dactyloquinone B and a 1:1 mixture of ilimaquinone and 5-epi-ilimaquinone. Their structures were determined on the basis of spectroscopic analyses and comparison with literature data. The isolated compounds were assessed for their cytotoxicity against a panel of human tumor cell lines (SF-268, H460, MCF-7, and HT-29) and a normal mammalian cell line (CHO-K1). All compounds were found to have activities in the range 1.8-46 μM and lacked selectivity for tumor versus normal cell lines.

Smenospongine, a Sesquiterpene Aminoquinone from a Marine Sponge, Induces G1 Arrest or Apoptosis in Different Leukemia Cells

Smenospongine, a sesquiterpene aminoquinone isolated from the marine sponge Dactylospongia elegans, was previously reported by us to induce erythroid differentiation and G1 phase arrest of K562 chronic myelogenous leukemia cells. In this study, we investigated the effect of smenospongine on the cell cycles of other leukemia cells, including HL60 human acute promyelocytic leukemia cells and U937 human histiocytic lymphoma cells by flow cytometric analysis. Smenospongine induced apoptosis dosedependently in HL60 and U937 cells. The smenospongine treatment increased expression of p21 and inhibited phosphorylation of Rb in K562 cells, suggesting the p21-Rb pathway play an important role in G1 arrest in K562 cells. However, the p21 promoter was not activated by the smenospongine treatment based on a luciferase assay using the transfected K562 cells. Smenospongine might induce p21 expression via another mechanism than transactivation of p21 promoter.

Smenospongine, a Sesquiterpene Aminoquinone from Marine Sponge, Induces G1 Arrest or Apoptosis in Different Leukemia Cells

Smenospongine, a sesquiterpene aminoquinone isolated from the marine sponge Dactylospongia elegans, was previously reported by us to induce erythroid differentiation and G1 phase arrest of K562 chronic myelogenous leukemia cells. In this study, we investigated the effect of smenospongine on the cell cycles of other leukemia cells, including HL60 human acute promyelocytic leukemia cells and U937 human histiocytic lymphoma cells by flow cytometric analysis. Smenospongine induced apoptosis dose-dependently in HL60 and U937 cells. The smenospongine treatment increased expression of p21 and inhibited phosphorylation of Rb in K562 cells, suggesting the p21-Rb pathway play an important role in G1 arrest in K562 cells. However, the p21 promoter was not activated by the smenospongine treatment based on a luciferase assay using the transfected K562 cells. Smenospongine might induce p21 expression via another mechanism than transactivation of p21 promoter.

Sesquiterpene Aminoquinones, from a Marine Sponge, Induce Erythroid Differentiation in Human Chronic Myelogenous Leukemia, K562 Cells.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Sesquiterpene aminoquinones, from a marine sponge, induce erythroid differentiation in human chronic myelogenous leukemia, K562 cells.

A new sesquiterpene aminoquinone, 5-epi-smenospongorine, together with nine known sesquiterpene quinone/phenols, was isolated as differentiation-inducing substances to K562 cells into erythroblast from the marine sponge Dactylospongia elegans. The structure-activity relationship study of these compounds clarified that the quinone skeleton is indispensable and the amino group plays an important role for their differentiation-inducing activity to K562 cells into erythroblast.

Pelorol from the tropical marine sponge Dactylospongia elegans.

From the dichloromethane solubles of the tropical marine sponge Dactylospongia elegans, a new aromatic substituted sesquiterpene, pelorol (1), and the known sesquiterpene, ilimaquinone (2), were isolated. The structures of 1 and 2 were deduced from their spectroscopic data. The biological activities of compounds 1 and 2 were assessed in a variety of bioassays, and both compounds were found to have weak antitrypanosomal and antiplasmodial effects.