Calamusins J-K: new anti-angiogenic sesquiterpenes from Sarcophyton glaucum

Diorygmones A-B, two new guaiane-sesquiterpenes from the cultured lichen mycobiont of Diorygma sp

Diorygma sp. is a native crustose-lichen in Vietnam. A mycobiont of this lichen was isolated, then cultivated. The present study described the isolation and structural elucidation of two new guaiane-type sesquiterpenes, namely diorygmones A-B. Their absolute chemical structures were elucidated by extensive 1D and 2D NMR analysis, high-resolution mass spectroscopy, electronic circular dichroism (ECD), and comparisons with the literatures. Compounds 1 and 2 were evaluated for cytotoxic activity against HepG2 cell line.

The application and sustainable development of coral in traditional medicine and its chemical composition, pharmacology, toxicology, and clinical research

This review discusses the variety, chemical composition, pharmacological effects, toxicology, and clinical research of corals used in traditional medicine in the past two decades. At present, several types of medicinal coral resources are identified, which are used in 56 formulas such as traditional Chinese medicine, Tibetan medicine, Mongolian medicine, and Uyghur medicine. A total of 34 families and 99 genera of corals are involved in medical research, with the Alcyoniidae family and Sarcophyton genus being the main research objects. Based on the structural types of compounds and the families and genera of corals, this review summarizes the compounds primarily reported during the period, including terpenoids, steroids, nitrogen-containing compounds, and other terpenoids dominated by sesquiterpene and diterpenes. The biological activities of coral include cytotoxicity (antitumor and anticancer), anti-inflammatory, analgesic, antibacterial, antiviral, immunosuppressive, antioxidant, and neurological properties, and a detailed summary of the mechanisms underlying these activities or related targets is provided. Coral toxicity mostly occurs in the marine ornamental soft coral Zoanthidae family, with palytoxin as the main toxic compound. In addition, nonpeptide neurotoxins are extracted from aquatic corals. The compatibility of coral-related preparations did not show significant acute toxicity, but if used for a long time, it will still cause toxicity to the liver, kidneys, lungs, and other internal organs in a dose-dependent manner. In clinical applications, individual application of coral is often used as a substitute for orthopedic materials to treat diseases such as bone defects and bone hyperplasia. Second, coral is primarily available in the form of compound preparations, such as Ershiwuwei Shanhu pills and Shanhu Qishiwei pills, which are widely used in the treatment of neurological diseases such as migraine, primary headache, epilepsy, cerebral infarction, hypertension, and other cardiovascular and cerebrovascular diseases. It is undeniable that the effectiveness of coral research has exacerbated the endangered status of corals. Therefore, there should be no distinction between the advantages and disadvantages of listed endangered species, and it is imperative to completely prohibit their use and provide equal protection to help them recover to their normal numbers. This article can provide some reference for research on coral chemical composition, biological activity, chemical ecology, and the discovery of marine drug lead compounds. At the same time, it calls for people to protect endangered corals from the perspectives of prohibition, substitution, and synthesis.

Marine natural products

Covering: January to December 2021This review covers the literature published in 2021 for marine natural products (MNPs), with 736 citations (724 for the period January to December 2021) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1425 in 416 papers for 2021), together with the relevant biological activities, source organisms and country of origin. Pertinent reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. An analysis of the number of authors, their affiliations, domestic and international collection locations, focus of MNP studies, citation metrics and journal choices is discussed.

Cembranoids from the Red Sea soft coral Sarcophyton glaucum protect against indomethacin-induced gastric injury

Soft corals and their secondary metabolites represent an exceptional source of potential drugs. In this regard, Sarcophyton glaucum-derived secondary metabolites were examined for their preventive activities against indomethacin-induced gastric ulcer. Extraction and chromatographic processing of a specimen of S. glaucum collected from the Red Sea waters of Jeddah city resulted in the isolation of eight metabolites including two furanone-based cembranoids (1 and 2), two known pyran-based cembranoids (3 and 4), a known aromadendrene derivative (5), a δ-lactone fatty acid derivative (6), and two known gorgostane-type sterols (7 and 8). Compounds 1 and 6 are new chemical structures, named Δ¹²⁽²⁰⁾-sarcophine and sarcoglaucanoate, respectively. In an initial pilot experiment, compounds 1 and 2 showed significant protective activities against indomethacin-induced peptic ulcer in rats. These data were evidenced by their ability to ameliorate the elevated ulcer indices and prevent histopathological alterations observed in the untreated animals. Their effects were mediated by enhanced mucin as shown by Alcian blue and periodic acid-Schiff (PAS) staining of stomach sections. Compounds 1 and 2 exerted significant antioxidant properties as they prevent reduced glutathione (GSH) depletion, malondialdehyde (MDA) accumulation, and superoxide dismutase (SOD) exhaustion. Furthermore, immunohistochemical analyses indicated that both compounds inhibited the expression of interleukin-6 (IL-6) and tumor necrosis-α (TNF-α) as compared to indomethacin alone-treated animals. These actions were accompanied by significant enhancement of tumor growth factor-β (TGF-β) expression. In conclusion, two cembranoids exhibited protective activities against indomethacin-induced peptic ulcer. This is, at least partly, mediated by their pro-mucin, antioxidant, anti-inflammatory, and TGF-β stimulating properties.

Structurally Diverse Diterpenes from the South China Sea Soft Coral Sarcophyton trocheliophorum

The present investigation of the South China Sea soft coral Sarcophyton trocheliophorum resulted in the discovery of six new polyoxygenated diterpenes, namely sartrocheliols A-E (1, 3, 5-8) along with four known ones, 2, 4, 9, and 10. Based on extensive spectroscopic data analysis, sartrocheliol A (1) was identified as an uncommon capnosane diterpene, while sartrocheliols B-E (3, 5-8) were established as cembrane diterpenes. They displayed diverse structural features not only at the distinctly different carbon frameworks but also at the various types of heterocycles, including the epoxide, γ-lactone, furan, and pyran rings. Moreover, their absolute configurations were determined by a combination of quantum mechanical-nuclear magnetic resonance (QM-NMR) approach, modified Mosher's method, and X-ray diffraction analysis. In the anti-tumor bioassay, compound 4 exhibited moderate cytotoxic activities against A549, H1975, MDA-MB-231, and H1299 cells with the IC₅₀ values ranging from 26.3 to 47.9 μM.

Secosteroidal hydrazides: Promising scaffolds for anti-breast cancer agents

A convenient and selective approach to 13,17-secoestra-1,3,5(10)-trien-17-oic acid hydrazides and their N'-(het)arylmethylene derivatives was disclosed and these novel types of secosteroids were screened for cytotoxicity against hormone-dependent human breast cancer cell line MCF-7. A number of 13,17-secoestra-1,3,5(10)-trien-17-oic acid [N'-(het)arylmethylene]hydrazides show significant cytotoxic effect comparable or superior to that for reference drug cisplatin. Compound 3l exhibits the highest activity with the IC₅₀ value of about 2 μM and is 2.8 times more active than cisplatin. Hit 13,17-secoestra-1,3,5(10)-trien-17-oic acid [N'-(het)arylmethylene]hydrazides 3d, 3l and 3q are characterized by high cytotoxicity and good selectivity towards MCF-7 breast cancer cells. The synthesized secosteroids may be considered as new promising antitumor agents.

Bioactive compounds from Matricaria chamomilla: structure identification, in vitro antiproliferative, antimigratory, antiangiogenic, and antiadenoviral activities

During our exploring the anticancer activity of some medicinal plants and their major metabolites, the aerial parts of the Egyptian Matricaria chamomilla (flowers and stems) were studied. GC-MS analysis of the organic soluble extracts of the flowers and stems fractions revealed the presence of 43 and 45 compounds, respectively. Individual chromatographic purification of the flowers and stems' extracts afforded three major compounds. Structures of these compounds were identified by 1D- and 2D-NMR and HRESI-MS spectroscopic data as bisabolol oxide A (1) and (E)-tonghaosu (2) (as mixture of ratio 2:1) from the flowers extract, meanwhile apigenin-7-β-d-glucoside (3) from the stems fraction. Biologically, the chamomile extracts announced significant antiproliferative activities exceeded in potency by ∼1.5 fold in case of the stem, recording GI₅₀ 13.16 and 17.04 μg/mL against Caco-2 and MCF-7, respectively. Both fractions were approximately equipotent against the migration of the same cell type down to 10 μg/mL together, compounds 1, 2 but not 3, showed considerable growth inhibition of the same cells at GI₅₀ 13.36 and 11.83 μg/mL, respectively. Interestingly, they were able to suppress Caco-2 colon cancer cells migration at 5.8 μg/mL and potently inactivate the VEGFR2 angiogenic enzyme (1.5-fold relative to sorafenib. The obtained compounds and corresponding chamomile extracts were evaluated against Adeno-7 virus, revealing that both chamomiles' extracts (flowers and stems) and their corresponding obtained compounds (1-3) were potent in their depletion to the Adeno 7 infectivity titer, however, the flower extract and compounds 1-2 were more effective than those of the stem extract and its end-product (3).

In vitro chemotherapeutic and antiangiogenic properties of cardenolides from Acokanthera oblongifolia (Hochst.) Codd

Acovenoside A (Acov-A) and acobioside A (Acob-A) were isolated from Acokanthera oblongifolia. Their anticancer properties were explored regarding, antiproliferative and antiangiogenic activities. The study included screening phase against six cancer cell lines followed by mechanistic investigation against HepG2 cancer cell line. The sulforhodamine-B (SRB) was used to determine their growth inhibitory power. In the other hand, flow cytometry techniques were recorded the cell death type and cell cycle analysis. The clonogenic (colony formation) and wound healing assays, enzyme-linked immunosorbent assay (ELISA) and molecular docking, were performed to evaluate the antiangiogenesis capability. Both compounds were strongly, inhibited four cancer cell lines at GI₅₀ less than 100 nM. The in vitro mechanistic investigation against HepG2 resulted in cell accumulations at G2M phase and induction of apoptosis upon treating cells separately, with 400 nM Acov-A and 200 nM Acob-A. Interestingly, the same concentrations were able to activate caspase-3 by 7.2 and 4.8-fold, respectively. Suppressing the clonogenic capacity of HepG2 cells (20 and 40 nM) and inhibiting the migration of the colon Caco-2 cancer cells were provoke the results of vascular endothelial growth factor receptor2 (VEGFR2) kinase enzyme inactivation. The docked study was highly supportive, to the antiangiogenic approach of both cardenolides. The isolated cardenolides could orchestrate pivotal events in fighting cancer.

Metal-free domino amination-Knoevenagel condensation approach to access new coumarins as potent nanomolar inhibitors of VEGFR-2 and EGFR

A metal-free, atom-economy and simple work-up domino amination-Knoevenagel condensation approach to construct new coumarin analogous (4a-f and 8a-e) was described. Further, new formyl (5a,d-f) and nitro (9a,d-f) coumarin derivatives were synthesized via C-N coupling reaction of various cyclic secondary amines and 4-chloro-3-(formyl-/nitro)coumarins (1a,c), respectively. The confirmed compounds were screened for their in vitro anti-proliferative activity against KB-3-1, A549 and PC3 human cancer cell lines using resazurin cellular-based assay. Among them, coumarin derivatives 4e and 8e displayed the best anti-cervical cancer potency (KB-3-1) with IC₅₀ values of 15.5 ± 3.54 and 21 ± 4.24 μM, respectively. Also, 4e showed the most promising cytotoxicity toward A549 with IC₅₀ value of 12.94 ± 1.51 μM. As well, 9d presented a more significant impact of potency against PC3 with IC₅₀ 7.31 ± 0.48 μM. Moreover, 8d manifested selectivity against PC3 (IC₅₀ = 20.16 ± 0.07 μM), while 8e was selective toward KB-3-1 cell line (IC₅₀ = 21 ± 4.24 μM). Matching with docking profile, the enzymatic assay divulged that 8e is a dual potent single-digit nanomolar inhibitor of VEGFR-2 and EGFR with IC₅₀ values of 24.67 nM and 31.6 nM that were almost equipotent to sorafenib (31.08 nM) and erlotinib (26.79 nM), respectively.