Desulfohaplosamate, a new phosphate-containing steroid from Dasychalina sp., is a selective cannabinoid CB2 receptor ligand

In silico identification of a phosphate marine steroid from Indonesian marine compounds as a potential inhibitor of phosphatidylinositol mannosyltransferase (PimA) in Mycobacterium tuberculosis

A higher death rate is associated with multiple factors, including medication resistance and co-infection with the human immunodeficiency virus (HIV). This shows the need to obtain new and effective drug candidates in improving tuberculosis (TB) treatment. In addition, the phosphatidylinositol mannosyltransferase (PimA) enzyme starts the production of phosphatidyl-myo-inositol. PimA has been identified as a key enzyme and an important area for further research in the development of anti-TB drugs. Previous research investigated various applications including marine resources driven by a deeper understanding of the distinctive features of the ecosystem and the diverse array of organisms. Therefore, this research aims to investigate the potential of Indonesian marine compounds as inhibitors of PimA, with a focus on binding energy, interaction modes, and stability using docking and molecular dynamics (MD) investigation methodologies. The results show that a total of 84 Indonesian marine compounds are effectively docked to the PimA to obtain compounds 21, 27, and 33 for further investigation. Based on the MD analysis, compound 27 (desulfohaplosamate) is the most promising candidate among the new MTB-PimA inhibitors. Compounds bind to PimA, as shown by a strong affinity of -30.09 kJ/mol, and form hydrogen bonds with the key amino acid residue Gly16. Furthermore, a stable complex is formed to easily analyze the antibacterial agents targeting MTB in the future.

Biological Activity and Structural Diversity of Steroids Containing Aromatic Rings, Phosphate Groups, or Halogen Atoms

This review delves into the investigation of the biological activity and structural diversity of steroids and related isoprenoid lipids. The study encompasses various natural compounds, such as steroids with aromatic ring(s), steroid phosphate esters derived from marine invertebrates, and steroids incorporating halogen atoms (I, Br, or Cl). These compounds are either produced by fungi or fungal endophytes or found in extracts of plants, algae, or marine invertebrates. To assess the biological activity of these natural compounds, an extensive examination of referenced literature sources was conducted. The evaluation encompassed in vivo and in vitro studies, as well as the utilization of the QSAR method. Numerous compounds exhibited notable properties such as strong anti-inflammatory, anti-neoplastic, anti-proliferative, anti-hypercholesterolemic, anti-Parkinsonian, diuretic, anti-eczematic, anti-psoriatic, and various other activities. Throughout the review, 3D graphs illustrating the activity of individual steroids are presented alongside images of selected terrestrial or marine organisms. Additionally, the review provides explanations for specific types of biological activity associated with these compounds. The data presented in this review hold scientific interest for academic science as well as practical implications in the fields of pharmacology and practical medicine. The analysis of the biological activity and structural diversity of steroids and related isoprenoid lipids provides valuable insights that can contribute to advancements in both theoretical understanding and applied research.

Structure-Based Virtual Screening and Molecular Dynamics Simulation Assessments of Depsidones as Possible Selective Cannabinoid Receptor Type 2 Agonists

The discovery of natural drug metabolites is a leading contributor to fulfilling the sustainable development goal of finding solutions to global health challenges. Depsidones are a class of polyketides that have been separated from lichens, fungi, sponges, and plants and possess various bioactivities, including cytotoxic, antimicrobial, antimalarial, antituberculosis, acetylcholinesterase and α-glucosidase inhibition, and anti-inflammatory effects. Endocannabinoid receptors (CB1 and CB2) are G-protein-coupled receptors (GPCRs), and their activation mediates many physiological processes. CB1 is the dominant subtype in the central nervous system, while CB2 is mainly expressed in the immune system. The two receptors exhibit high heterogeneity, making developing selective ligands a great challenge. Attempts to develop CB2 selective agonists for treating inflammatory diseases and neuropathic pain have not been successful due to the high homology of the binding sites of the CB receptors. In this work, 235 depsidones from various sources were investigated for the possibility of identifying CB2-selective agonists by performing multiple docking studies, including induced fit docking and Prime/molecular mechanics-generalized Born surface area (MM-GBSA) calculations to predict the binding mode and free energy. Simplicildone J (10), lobaric acid (110), mollicellin Q (101), garcinisidone E (215), mollicellin P (100), paucinervin Q (149), and boremexin C (161) had the highest binding scores (-12.134 kcal/mol, -11.944 kcal/mol, -11.479 kcal/mol, -11.394 kcal/mol, -11.322 kcal/mol, -11.305 kcal/mol, and -11.254 kcal/mol, respectively) when screened against the CB2 receptor (PDB ID: 6KPF). The molecular dynamic simulation was performed on the compounds with the highest binding scores. The computational outcomes show that garcinisidone E (215) and paucinervin Q (149) could be substantial candidates for CB2 receptor activation and warrant further in vivo and in vitro investigations.

Vinyl azides in organic synthesis: an overview

Among organic azides, vinyl azides have attracted significant attention, because of their unique properties in organic synthesis, which led to reports of many types of research on this versatile conjugated azide in recent years. This magical precursor can also be converted into intermediates such as iminyl radicals, 2H-azirines, iminyl metal complexes, nitrilium ions, and iminyl ions, making this compound useful in heterocycle synthesis.

The phosphate ester group in secondary metabolites

Covering: 2000 to mid-2021The phosphate ester is a versatile, widespread functional group involved in a plethora of biological activities. Its presence in secondary metabolites, however, is relatively rare compared to other functionalities and thus is part of a rather unexplored chemical space. Herein, the chemistry of secondary metabolites containing the phosphate ester group is discussed. The text emphasizes their structural diversity, biological and pharmacological profiles, and synthetic approaches employed in the phosphorylation step during total synthesis campaigns, covering the literature from 2000 to mid-2021.

The Endocannabinoid System and Invertebrate Neurodevelopment and Regeneration

Cannabis has long been used for its medicinal and psychoactive properties. With the relatively new adoption of formal medicinal cannabis regulations worldwide, the study of cannabinoids, both endogenous and exogenous, has similarly flourished in more recent decades. In particular, research investigating the role of cannabinoids in regeneration and neurodevelopment has yielded promising results in vertebrate models. However, regeneration-competent vertebrates are few, whereas a myriad of invertebrate species have been established as superb models for regeneration. As such, this review aims to provide a comprehensive summary of the endocannabinoid system, with a focus on current advances in the area of endocannabinoid system contributions to invertebrate neurodevelopment and regeneration.

Marine Natural Products from Indonesian Waters

Natural products are primal and have been a driver in the evolution of organic chemistry and ultimately in science. The chemical structures obtained from marine organisms are diverse, reflecting biodiversity of genes, species and ecosystems. Biodiversity is an extraordinary feature of life and provides benefits to humanity while promoting the importance of environment conservation. This review covers the literature on marine natural products (MNPs) discovered in Indonesian waters published from January 1970 to December 2017, and includes 732 original MNPs, 4 structures isolated for the first time but known to be synthetic entities, 34 structural revisions, 9 artifacts, and 4 proposed MNPs. Indonesian MNPs were found in 270 papers from 94 species, 106 genera, 64 families, 32 orders, 14 classes, 10 phyla, and 5 kingdoms. The emphasis is placed on the structures of organic molecules (original and revised), relevant biological activities, structure elucidation, chemical ecology aspects, biosynthesis, and bioorganic studies. Through the synthesis of past and future data, huge and partly undescribed biodiversity of marine tropical invertebrates and their importance for crucial societal benefits should greatly be appreciated.

Steroid phosphate esters and phosphonosteroids and their biological activities

Steroid phosphate esters are very rare natural lipids that have been comparatively recently isolated from fractions of polar lipids of marine sponges and starfish. These steroids exhibit interesting biological activities. When using the PASS computer program, we showed that many of steroid phosphate esters showed antifungal, antihypercholesterolemic, anesthetic, and other activities with a confidence of 73 to 93%. In addition, some of them can be used as inhibitors of cholesterol synthesis and show hepatoprotection properties. Phosphonosteroids demonstrate antineoplastic and antihypercholesterolemic activities with a certainty of 85 to 90%. And also, they can be used as ovulation inhibitors or female steroid contraceptives with confidence from 86 to 98%.

Small Molecules from Nature Targeting G-Protein Coupled Cannabinoid Receptors: Potential Leads for Drug Discovery and Development

The cannabinoid molecules are derived from Cannabis sativa plant which acts on the cannabinoid receptors types 1 and 2 (CB1 and CB2) which have been explored as potential therapeutic targets for drug discovery and development. Currently, there are numerous cannabinoid based synthetic drugs used in clinical practice like the popular ones such as nabilone, dronabinol, and Δ(9)-tetrahydrocannabinol mediates its action through CB1/CB2 receptors. However, these synthetic based Cannabis derived compounds are known to exert adverse psychiatric effect and have also been exploited for drug abuse. This encourages us to find out an alternative and safe drug with the least psychiatric adverse effects. In recent years, many phytocannabinoids have been isolated from plants other than Cannabis. Several studies have shown that these phytocannabinoids show affinity, potency, selectivity, and efficacy towards cannabinoid receptors and inhibit endocannabinoid metabolizing enzymes, thus reducing hyperactivity of endocannabinoid systems. Also, these naturally derived molecules possess the least adverse effects opposed to the synthetically derived cannabinoids. Therefore, the plant based cannabinoid molecules proved to be promising and emerging therapeutic alternative. The present review provides an overview of therapeutic potential of ligands and plants modulating cannabinoid receptors that may be of interest to pharmaceutical industry in search of new and safer drug discovery and development for future therapeutics.

The antinociceptive triterpene β-amyrin inhibits 2-arachidonoylglycerol (2-AG) hydrolysis without directly targeting cannabinoid receptors

BACKGROUND AND PURPOSE

Pharmacological activation of cannabinoid CB(1) and CB(2) receptors is a therapeutic strategy to treat chronic and inflammatory pain. It was recently reported that a mixture of natural triterpenes α- and β-amyrin bound selectively to CB(1) receptors with a subnanomolar K(i) value (133 pM). Orally administered α/β-amyrin inhibited inflammatory and persistent neuropathic pain in mice through both CB(1) and CB(2) receptors. Here, we investigated effects of amyrins on the major components of the endocannabinoid system.

EXPERIMENTAL APPROACH

We measured CB receptor binding interactions of α- and β-amyrin in validated binding assays using hCB(1) and hCB(2) transfected CHO-K1 cells. Effects on endocannabinoid transport in U937 cells and breakdown using homogenates of BV2 cells and pig brain, as well as purified enzymes, were also studied.

KEY RESULTS

There was no binding of either α- or β-amyrin to hCB receptors in our assays (K(i) > 10 µM). The triterpene β-amyrin potently inhibited 2-arachidonoyl glycerol (2-AG) hydrolysis in pig brain homogenates, but not that of anandamide. Although β-amyrin only weakly inhibited purified human monoacylglycerol lipase (MAGL), it also inhibited α,β-hydrolases and more potently inhibited 2-AG breakdown than α-amyrin and the MAGL inhibitor pristimerin in BV2 cell and pig brain homogenates.

CONCLUSIONS AND IMPLICATIONS

We propose that β-amyrin exerts its analgesic and anti-inflammatory pharmacological effects via indirect cannabimimetic mechanisms by inhibiting the degradation of the endocannabinoid 2-AG without interacting directly with CB receptors. Triterpenoids appear to offer a very broad and largely unexplored scaffold for inhibitors of the enzymic degradation of 2-AG.

LINKED ARTICLES

This article is part of a themed section on Cannabinoids. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.167.issue-8.

Marine natural products

This review covers the literature published in 2011 for marine natural products, with 870 citations (558 for the period January to December 2011) 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 (1152 for 2011), together with the relevant biological activities, source organisms and country of origin. Biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.

The True Identity of the Triterpene Component of Wyethia mollis, a Lanosta-diene Containing a Tetrahydropyran E-ring

The crystal structure of a triterpene component of Wyethia mollis has been obtained and compared with the previously reported structure of the compound. The compound in the crystal structure, lanosta-8,24-dien-3-one, 16,23-epoxy-(16β, 23 R), (1), is different from the previously reported compound, but has identical NMR and mass spectrometric data. The revised structure contains a tetrahydropyran E ring, a structural moiety rare in steroid triterpenes.

Leucettamols, bifunctionalized marine sphingoids, act as modulators of TRPA1 and TRPM8 channels

Leucettamols, bifunctionalized sphingoid-like compounds obtained from a marine sponge Leucetta sp., act as non-electrophilic activators of the TRPA1 channel and potent inhibitors of the icilin-mediated activation of the TRPM8 channel, while they are inactive on CB₁, CB₂ and TRPV1 receptors. Leucettamols represent the first compounds of marine origin to target TRPA1 and the first class of natural products to inhibit TRPM8 channels. The preparation of a small series of semi-synthetic derivatives revealed interesting details on the structure-activity relationships within this new chemotype of simple acyclic TRP modulators.

Polyhydroxylated sterols from the Indonesian soft coral Sinularia sp. and their effect on farnesoid X-activated receptor

Chemical investigation of the Indonesian soft coral Sinularia sp. resulted in the isolation of three known (1, 2 and 7) and five new (3-6 and 8) sterols, characterized by either 24-methylcholestane or gorgostane skeletons. The stereostructures of the new compounds have been elucidated by application of HR-MS and 2D NMR techniques. The isolated steroids have been evaluated for their interaction with the farnesoid X-activated receptor (FXR) and some of them, including the new compound 3 and gorgosterol (7), showed a consistent antagonistic activity, potentially useful for the treatment of cholestasis. The FXR antagonistic activity of gorgosterol (7) was also supported by gene expression experiments. Our results represent the first evaluation of soft coral steroids for interaction with nuclear receptors and qualify gorgosterol (7) as a new chemotype of FXR antagonist.