Acanthosterol sulfates A-J: ten new antifungal steroidal sulfates from a marine sponge Acanthodendrilla sp

Synthesis of bile acid-thiadiazole conjugates as antibacterial and antioxidant agents

The synthesis, characterization, and antibacterial and antioxidant activity of thiadiazole-deoxycholic/lithocholic acid conjugates are described in this communication. The structures of the synthesised bile acid-thiadiazole conjugates were studied using 1H NMR, 13C NMR and FTIR. Compounds 4c (IC50; 15.34 ± 0.07 μM) and 5c (IC50; 13.45 ± 0.25 μM) demonstrated greater antioxidant activity than the reference compound ascorbic acid (IC50; 20.72 ± 1.02 μM) in DPPH assay. The most effective conjugates against P. vulgarise were 4c (IC50; 24 ± 2.3 μM), 4 g (IC50; 29 ± 2.5 μM), and 5c (IC50; 93 ± 3.6 μM), whereas the most effective conjugates against E. coli were 4e (IC50; 55 ± 2.1 μM) and 4f (IC50; 52 ± 3.5 μM). Conjugates 4c and 5c were the most effective against B. megaterium of all the synthesised conjugates, with IC50 values of 15 ± 1.08 and 20 ± 1.1 μM, respectively. Thus, a large library of compounds derived from bile acid can be easily synthesised for extensive structure-activity relationship studies in order to identify the most appropriate antibacterial agents and antioxidant activity.

Bioactive Steroids Bearing Oxirane Ring

This review explores the biological activity and structural diversity of steroids and related isoprenoid lipids, with a particular focus on compounds containing an oxirane ring. These natural compounds are derived from fungi, fungal endophytes, as well as extracts of plants, algae, and marine invertebrates. To evaluate their biological activity, an extensive examination of refereed literature sources was conducted, including in vivo and in vitro studies and the utilization of the QSAR method. Notable properties observed among these compounds include strong anti-inflammatory, antineoplastic, antiproliferative, anti-hypercholesterolemic, antiparkinsonian, diuretic, anti-eczematic, anti-psoriatic, and various other activities. Throughout this review, 3D graphs illustrating the activity of individual steroids are presented, accompanied by images of selected terrestrial or marine organisms. Furthermore, this review provides explanations for specific types of biological activity associated with these compounds. The data presented in this review are of scientific interest to the academic community and carry practical implications in the fields of pharmacology and medicine. By analyzing the biological activity and structural diversity of steroids and related isoprenoid lipids, this review offers valuable insights that contribute to both theoretical understanding and applied research. This review draws upon data from various authors to compile information on the biological activity of natural steroids containing an oxirane ring.

Bile acid-based receptors and their applications in recognition

Ion recognition has attracted great attention in the past decades because of its important role in biology, medicine, environment, and chemistry. The combination of rigidity, curved structure and amphiphilic nature makes bile acids a host system for ion recognition. In addition, the availability of hydroxyl groups in bile acids can be used for further derivatization to develop various ion recognition receptors. The detection of ions is revealed by the binding constant k_a value, log approach, and UV-visible or ¹H NMR titration, while visual detection is determined by gel-phase transition, colorimetric and fluorescent probes. In this review, we have discussed the bile acid-based receptors and their ion-recognition capability. These bile acid-based systems have the potential for the development of anion transport for biological activity.

Controlled release of 5-fluorouracil to melanoma cells using a hydrogel/micelle composites based on deoxycholic acid and carboxymethyl chitosan

5-Fluorouracil (5-FU) is an antimetabolite drug widely used for the treatment of skin cancer. Despite its proven efficacy in treating malignancies, its systemic administration is limited due to severe side effects. To address this issue, topical delivery of 5-FU has been proposed as an alternative approach for the treatment of skin cancer, however, the poor permeability of 5-FU through the skin is still a challenge. Here, we introduced a pH-responsive micellar hydrogel system based on deoxycholic acid micelle (DCA Mic) and carboxymethyl chitosan hydrogel (CMC Hyd) to enhance 5-FU efficacy against skin cancer and reduce its systemic side effects by improving its delivery into the skin. The properties of the Mic/Hyd system were determined by Fourier-transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), zeta sizer, atomic force microscopy (AFM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Drug release studies showed pH-dependent properties of the Hyd. The final formulation was demonstrated to have enhanced anticancer activity than 5-FU against the growth of melanoma cells. The 5-FU@Mic-Hyd could be a promising delivery platform with enhanced efficacy in the management of skin cancer without systemic toxicity.

Sponge-associated sp. RM66 metabolome induction with N-acetylglucosamine: Antibacterial, antifungal and anti-trypanosomal activities

The marine sponge Amphimedon sp., collected from Hurghada (Egypt) was investigated for its sponge-derived actinomycetes diversity. Nineteen actinomycetes were cultivated and phylogenetically identified using 16S rDNA gene sequencing were carried out. The strains belong to genera Kocuria, Dietzia, Micrococcus, Microbacterium and Streptomyces. Many silent biosynthetic genes clusters were investigated using genome sequencing of actinomycete strains and has revealed in particular the genus Streptomyces that has indicated their exceptional capacity for the secondary metabolites production that not observed under classical cultivation conditions. In this study, the effect of N-acetylglucosamine on the metabolome of Streptomyces sp. RM66 was investigated using three actinomycetes media (ISP2, M1 and MA). In total, twelve extracts were produced using solid and liquid fermentation approaches. Liquid chromatography-high resolution tandem mass spectrometry (LC-HRMS/MS) data were analysed using metabolomics tools to compare natural product production across all crude extracts. Our study highlighted the elicitation effect of N-acetylglucosamine on the secondary metabolite profiles of Streptomyces sp. RM66. These results highlight the of N-acetylglucosamine application as an elicitor to induce the cryptic metabolites and for increasing the chemical diversity. All the twelve extracts were tested for their antibacterial activity was tested against Staphylococcus aureus NCTC 8325, antifungal activity against Candida albicans 5314 (ATCC 90028) and anti-trypanosomal activity against Trypanosoma brucei brucei. Extract St1 showed the most potent one with activities 2.3, 3.2 and 4.7 ug/ml as antibacterial, antifungal and anti-trypanosomal, respectively.

Sulfated and Sulfur-Containing Steroids and Their Pharmacological Profile

The review focuses on sulfated steroids that have been isolated from seaweeds, marine sponges, soft corals, ascidians, starfish, and other marine invertebrates. Sulfur-containing steroids and triterpenoids are sourced from sedentary marine coelenterates, plants, marine sediments, crude oil, and other geological deposits. The review presents the pharmacological profile of sulfated steroids, sulfur-containing steroids, and triterpenoids, which is based on data obtained using the PASS program. In addition, several semi-synthetic and synthetic epithio steroids, which represent a rare group of bioactive lipids that have not yet been found in nature, but possess a high level of antitumor activity, were included in this review for the comparative pharmacological characterization of this class of compounds. About 140 steroids and triterpenoids are presented in this review, which demonstrate a wide range of biological activities. Therefore, out of 71 sulfated steroids, thirteen show strong antitumor activity with a confidence level of more than 90%, out of 50 sulfur-containing steroids, only four show strong antitumor activity with a confidence level of more than 93%, and out of eighteen epithio steroids, thirteen steroids show strong antitumor activity with a confidence level of 91% to 97.4%.

Recent advances in the bile acid based conjugates/derivatives towards their gelation applications

Bile acids have contributed immensely to hydrogel research due to their peculiar physicochemical properties and biocompatibility. The wide accessibility of bile acids and their straightforward derivatization methods make them attractive building blocks for the design of novel hydrogels systems to deliver biomolecules, drugs, and vaccines. This review conceptualizes recent developments in bile acid-based hydrogels and their applications. These bile-based hydrogels have the ability to absorb carbon dioxide efficiently and may potentially work as alternative materials for carbon dioxide capture and storage. The hydrogels hold great potential in medicine and biology applications as drug carriers and models for fundamental self-assembly in pathological conditions. Herein, we have summarized the efforts that have been made for the development of molecular hydrogels in terms of biocompatibility, therapeutic applications, and challenges associated with existing molecular hydrogels.

Gracilosulfates A-G, Monosulfated Polyoxygenated Steroids from the Marine Sponge Haliclona gracilis

Seven new polyoxygenated steroids belonging to a new structural group of sponge steroids, gracilosulfates A-G (1-7), possessing 3β-O-sulfonato, 5β,6β epoxy (or 5(6)-dehydro), and 4β,23-dihydroxy substitution patterns as a common structural motif, were isolated from the marine sponge Haliclona gracilis. Their structures were determined by NMR and MS methods. The compounds 1, 2, 4, 6, and 7 inhibited the expression of prostate-specific antigen (PSA) in 22Rv1 tumor cells.

Antimicrobial Lipids from Plants and Marine Organisms: An Overview of the Current State-of-the-Art and Future Prospects

In the actual post-antibiotic era, novel ways of rethinking antimicrobial research approaches are more urgent than ever. Natural compounds with antimicrobial activity such as fatty acids and monoacylglycerols have been investigated for decades. Additionally, the interest in other lipid classes as antimicrobial agents is rising. This review provides an overview on the research about plant and marine lipids with potential antimicrobial activity, the methods for obtaining and analyzing these compounds, with emphasis on lipidomics, and future perspectives for bioprospection and applications for antimicrobial lipids. Lipid extracts or lipids isolated from higher plants, algae or marine invertebrates are promising molecules to inactivate a wide spectrum of microorganisms. These lipids include a variety of chemical structures. Present and future challenges in the research of antimicrobial lipids from natural origin are related to the investment and optimization of the analytical workflow based on lipidomics tools, complementary to the bioassay-guided fractionation, to identify the active compound(s). Also, further work is needed regarding the study of their mechanism of action, the structure-activity relationship, the synergistic effect with conventional antibiotics, and the eventual development of resistance to lipids, which, as far as is known, is unlikely.

Updates in bile acid-bioactive molecule conjugates and their applications

Bile acid conjugates are emerging as important chemical resources due to their low cost and wide availability of bile acids, making them privileged molecules in drug carrier systems and building blocks for derivatization and chiral template introduction into bioactive molecules. In recent years, bile acids as scaffolds in supramolecular, medicinal, and material chemistry attracted prime focus of researchers as an area of research to be followed with passion. Due to peculiar physicochemical and biological properties, bile acid exhibited various applications in biomedical and pharmaceutical fields. In this review, the bile acid conjugations with different bioactive compounds have been discussed to understand their influence on the bioavailability of bioactive compounds.

Design, Synthesis, and Anti-bacterial Activity of Novel Deoxycholic Acid- Amino Alcohol Conjugates

Background:

Numerous synthetic bile acid derivatives have been recognized for their various biological activities. Among these, bile acid amides have emerged as an attractive antibacterial agent. We herein illustrate the synthesis and antibacterial evaluation of deoxycholic acidamino alcohols conjugates.

Objective:

Design and Synthesis of novel deoxycholic acid-amino alcohol conjugates to investigate their antibacterial activity against E. coli and S. aureus.

Methods:

Novel deoxycholic acid-amino alcohol conjugates were synthesized, from conjugation of deoxycholic acid-NHS ester with amino alcohols. Various amino alcohols moieties were appended to the C24 position of deoxycholic acid to yield deoxycholic acid-amino alcohol conjugates. All the synthesized compounds were characterized by 1H NMR, 13C NMR, IR and massspectroscopy. The entire synthesized deoxycholic acid-amino alcohol conjugates were evaluated for their antibacterial activity against E. coli and S. aureus using the broth dilution method.

Results:

The outcome illustrated that some of the novel deoxycholic acid-amino alcohol conjugates exhibited enhanced anti-bacterial activities. Amongst them, deoxycholic acid-amino alcohol conjugate containing (-R)-2-aminocyclohexanol (1) demonstrated promising efficacy against both strains S. aureus ATCC 25923 (MIC 15 μg/mL) and E. coli ATCC 25922 (MIC 45 μg/mL) and was identified as a lead molecule.

Conclusion:

Numbers of novel deoxycholic acid-amino alcohol conjugates were synthesized and their antimicrobial activities provided useful information that the potency was strongly depending on the structures of deoxycholic acid-amino alcohol conjugates.

SULFATION PATHWAYS: Sources and biological activities of marine sulfated steroids

Marine environment is rich in structurally unique molecules and can be an inspiring source of novel drugs. Currently, six marine-derived drugs are in the market with FDA approval and several more are in the clinical pipeline. Structurally diverse and complex secondary metabolites have been isolated from the marine world and these include sulfated steroids. Biological activities of nearly 150 marine sulfated steroids reported from 1978 to 2017 are compiled and described, namely antimicrobial, antitumor, cardiovascular and antifouling activities. Structure-activity relationship for each activity is discussed.

Emerging sulfated flavonoids and other polyphenols as drugs: nature as an inspiration

Nature uses sulfation of endogenous and exogenous molecules mainly to avoid potential toxicity. The growing importance of natural sulfated molecules, as modulators of a number of physiological and pathological processes, has inspired the synthesis of non-natural sulfated scaffolds. Until the 1990s, the synthesis of sulfated small molecules was almost restricted to derivatives of flavonoids and aimed mainly at structure elucidation and plant biosynthesis studies. Currently, the synthesis of this type of compounds concerns structurally diverse scaffolds and is aimed at the development of potential drugs and/or exploitation of the biological effects of sulfated metabolites. Some important hit compounds are emerging from sulfated flavonoids and other polyphenols mainly as anticoagulant and antiviral agents. When compared with polymeric macromolecules such as heparins, sulfated small molecules could be of value in therapeutics due to their hydrophobic nature that can contribute to improve the bioavailability. This review highlights the synthetic approaches that were applied to obtain monosulfated or polysulfated phenolic small molecules and compiles the diverse biological activities already reported for this type of derivatives. Toxicity and pharmacokinetic parameters of this emerging class of derivatives will also be considered, emphasizing their value for therapeutic applications.

Synthesis and antimicrobial evaluation of bile acid tridentate conjugates

Two series of novel bile acid tridentate conjugates with different linkers were synthesized and characterized, and their biological activities in vitro were evaluated. The procedure was straightforward and efficient to be carried out with high overall yield. The antimicrobial activity of the synthesized compounds against Saccharomyces cerevisiae, Aspergillus niger, Escherichia coli and Staphylococcus aureus was investigated in vitro. The best activity of minimal inhibitory concentrations (MICs) for 1c, 1c', 2c and 2c' against S. cerevisiae was up to 0.125 microg/mL.

Eurysterols A and B, cytotoxic and antifungal steroidal sulfates from a marine sponge of the genus Euryspongia

Two new steroidal sulfates, eurysterols A (1) and B (2), were isolated from an undescribed marine sponge of the genus Euryspongia collected in Palau. The structures of the new compounds were assigned by NMR spectroscopic data interpretation. Compounds 1 and 2 showed cytotoxicity against human colon carcinoma (HCT-116) cells with IC50 values of 2.9 and 14.3 microg/mL, respectively, and exhibited antifungal activity against amphotericin B-resistant and wild-type strains of Candida albicans with MIC values, in turn, of 15.6 and 62.5 microg/mL.

Marine sponges as pharmacy

Marine sponges have been considered as a gold mine during the past 50 years, with respect to the diversity of their secondary metabolites. The biological effects of new metabolites from sponges have been reported in hundreds of scientific papers, and they are reviewed here. Sponges have the potential to provide future drugs against important diseases, such as cancer, a range of viral diseases, malaria, and inflammations. Although the molecular mode of action of most metabolites is still unclear, for a substantial number of compounds the mechanisms by which they interfere with the pathogenesis of a wide range of diseases have been reported. This knowledge is one of the key factors necessary to transform bioactive compounds into medicines. Sponges produce a plethora of chemical compounds with widely varying carbon skeletons, which have been found to interfere with pathogenesis at many different points. The fact that a particular disease can be fought at different points increases the chance of developing selective drugs for specific targets.

Lembehsterols A and B, novel sulfated sterols inhibiting thymidine phosphorylase, from the marine sponge Petrosia strongylata

Lembehsterols A (1) and B (2), two novel sulfated sterols, were isolated from the marine sponge Petrosia strongylata. Both sterols showed inhibitory activity against thymidine phosphorylase, which is an enzyme related to angiogenesis in solid tumors. The structures of these sulfated sterols were established on the basis of chemical and physicochemical evidence.