Isolation of 20 glycosides from the starfish Henricia downeyae, collected in the Gulf of Mexico

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.

Antidiabetic lanostane triterpenoids from the fruiting bodies of Ganoderma weberianum

Eight previously undescribed lanostane triterpenoids, ganodeweberiols A ∼ H (1-8), together with eighteen known compounds (9-26), were isolated from the fruiting bodies of Ganoderma weberianum. The structures and absolute configurations of the new compounds were determined by extensive spectroscopic analysis, as well as NMR chemical shifts and electronic circular dichroism (ECD) calculations. Compounds 2, 7, 12, and 14 showed significant α-glucosidase inhibitory activity with IC₅₀ values ranging from 35.3 μM ∼ 223.4 μM compared to the positive control acarbose (IC₅₀, 304.6 μM). Kinetic study indicated that the most potent compound 12 was a mixed type inhibitor for α-glucosidase. Molecular docking simulation revealed the interactions of 12 with α-glucosidase. Additionally, Compounds 3 and 6 inhibited glucagon-induced hepatic glucose production in HepG2 cells with EC₅₀ values of 42.0 and 85.9 μM, respectively. Further study revealed that compounds 3 and 6 inhibited hepatic glucose production by suppression glucagon-induced cAMP accumulation. Moreover, compounds 3 and 26 were active against HeLa cell line with IC₅₀ values of 17.0 and 6.8 μM, 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%.

Surveillance of densoviruses and mesomycetozoans inhabiting grossly normal tissues of three Aotearoa New Zealand asteroid species

Asteroid wasting events and mass mortality have occurred for over a century. We currently lack a fundamental understanding of the microbial ecology of asteroid disease, with disease investigations hindered by sparse information about the microorganisms associated with grossly normal specimens. We surveilled viruses and protists associated with grossly normal specimens of three asteroid species (Patiriella regularis, Stichaster australis, Coscinasterias muricata) on the North Island / Te Ika-a-Māui, Aotearoa New Zealand, using metagenomes prepared from virus and ribosome-sized material. We discovered several densovirus-like genome fragments in our RNA and DNA metagenomic libraries. Subsequent survey of their prevalence within populations by quantitative PCR (qPCR) demonstrated their occurrence in only a few (13%) specimens (n = 36). Survey of large and small subunit rRNAs in metagenomes revealed the presence of a mesomycete (most closely matching Ichthyosporea sp.). Survey of large subunit prevalence and load by qPCR revealed that it is widely detectable (80%) and present predominately in body wall tissues across all 3 species of asteroid. Our results raise interesting questions about the roles of these microbiome constituents in host ecology and pathogenesis under changing ocean conditions.

Asterosaponins: Structures, Taxonomic Distribution, Biogenesis and Biological Activities

Asterosaponins are a class of steroid oligoglycosides isolated from starfish with characteristic structures and diverse biological activities. In this review, we have attempted to combine the most important data concerning asterosaponins and give a list of these secondary metabolites with their structural peculiarities. The purpose of this review is to provide a brief but as complete as possible principal information about their chemical structures, taxonomic distribution in the marine environment, distribution in different geographical areas and depths, some properties, biological activities, and functions. Some other rare steroid metabolites from starfish, closely related in structures and probably biogenesis to asterosaponins, are also discussed.

A new ergostane derivative from the leaves of Heynea trijuga Roxburgh

During the course of searching for structurally interesting and bioactive compounds, a further chemical investigation of the leaves of Heynea trijuga Roxburgh was performed, which led to the isolation of a new ergostane derivative, named 3β, 4β, 20S-trihydroxyergosta-5, 24(28)-dien-16-one (1), together with five known sterides (3β, 23S)-ergosta-5, 24(28)-diene-3, 23-diol (2), ergosta-5, 24(28)-diene-3β-diol (3), stigmast-5-ene-3β, 7α-diol (4), sitoindoside I (5) and stigmast-3β, 5α, 6β-triol (6). The structure of the new compound was elucidated using a combination of 1 D, 2 D NMR techniques and HR-EI-MS analyses. All the compounds were evaluated for cytotoxic activity against tumor cell line BEL-7402 by MTT method.

Discrimination of Regioisomeric and Stereoisomeric Saponins from Aesculus hippocastanum Seeds by Ion Mobility Mass Spectrometry

Modern mass spectrometry methods provide a huge benefit to saponin structural characterization, especially when combined with collision-induced dissociation experiments to obtain a partial description of the saponin (ion) structure. However, the complete description of the structures of these ubiquitous secondary metabolites remain challenging, especially since isomeric saponins presenting small differences are often present in a single extract. As a typical example, the horse chestnut triterpene glycosides, the so-called escins, comprise isomeric saponins containing subtle differences such as cis-trans ethylenic configuration (stereoisomers) of a side chain or distinct positions of an acetyl group (regioisomers) on the aglycone. In the present paper, the coupling of liquid chromatography and ion mobility mass spectrometry has been used to distinguish regioisomeric and stereoisomeric saponins. Ion mobility arrival time distributions (ATDs) were recorded for the stereoisomeric and regioisomeric saponin ions demonstrating that isomeric saponins can be partially separated using ion mobility on a commercially available traveling wave ion mobility (TWIMS) mass spectrometer. Small differences in the ATD can only be monitored when the isomeric saponins are separated with liquid chromatography prior to the IM-MS analysis. However, gas phase separation between stereoisomeric and regioisomeric saponin ions can be successfully realized, without any LC separation, on a cyclic ion mobility-enabled quadrupole time-of-flight (Q-cIM-oaToF) mass spectrometer. The main outcome of the present paper is that the structural analysis of regioisomeric and stereoisomeric natural compounds that represents a real challenge can take huge advantages of ion mobility experiments but only if increased ion mobility resolution is attainable.

Chemical Ecology of Chemosensation in Asteroidea: Insights Towards Management Strategies of Pest Species

Within the Phylum Echinodermata, the class Asteroidea, commonly known as starfish and sea stars, encompasses a large number of benthos inhabiting genera and species with various feeding modalities including herbivores, carnivores, omnivores and detritivores. The Asteroidea rely on chemosensation throughout their life histories including hunting prey, avoiding or deterring predators, in the formation of spawning aggregations, synchronizing gamete release and targeting appropriate locations for larval settlement. The identities of many of the chemical stimuli that mediate these physiological and behavioural processes remain unresolved even though evidence indicates they play pivotal roles in the functionality of benthic communities. Aspects of chemosensation, as well as putative chemically-mediated behaviours and the molecular mechanisms of chemoreception, within the Asteroidea are reviewed here, with particular reference to the coral reef pest the Crown-of-Thorns starfish Acanthaster planci species complex, in the context of mitigation of population outbreaks.

Furostane Series Asterosaponins and Other Unusual Steroid Oligoglycosides from the Tropical Starfish Pentaceraster regulus

Seven new asterosaponins, pentaregulosides A-G (1-7), including two furostane-type steroid oligoglycosides (2, 3), along with four previously known compounds (8-11) were isolated from the ethanolic extract of the starfish Pentaceraster regulus, collected off the coast of Vietnam. The structures of 1-7 were elucidated by extensive NMR and ESIMS techniques as well as chemical transformations. The aglycons of compounds 1 and 3 have not previously been observed in starfish steroid oligoglycosides, while the aglycons of compounds 2 and 4-6 are very rare for this structural group. Compound 1 exhibited cytotoxic activity with an IC₅₀ value of 6.4 ± 0.3 μM against RAW 264.7 murine macrophages. In contrast, nontoxic asterosaponins 3, 4, and 5 showed a potential immunomodulatory action at a concentration of 5 μM, reducing by 40%, 28%, and 55%, respectively, reactive oxygen species formation in the RAW 264.7 cells, co-stimulated with the pro-inflammatory endotoxic lipopolysaccharide from E. coli.

Cyclic Steroid Glycosides from the Starfish Echinaster luzonicus: Structures and Immunomodulatory Activities

Five new steroid glycosides, luzonicosides B-E (2-5), belonging to a rare structure group of marine glycosides, containing carbohydrate moieties incorporated into a macrocycle, and a related open carbohydrate chain steroid glycoside, luzonicoside F (6), were isolated from the starfish Echinaster luzonicus along with the previously known cyclic steroid glycoside luzonicoside A (1). The structures of compounds 2-6 were established by extensive NMR and ESIMS techniques as well as chemical transformations. Luzonicoside A (1) at concentrations of 0.01-0.1 μM was shown to be potent in lysosomal activity stimulation, intracellular ROS level elevation, and NO synthesis up-regulation in RAW 264.7 murine macrophages. Luzonicoside D (4) was less active in these biotests.

Chemical constituents and bioactivities of starfish

Starfish have been the research topic in many chemical and pharmacological laboratories due to their complex secondary metabolites and diverse bioactivities. The aim of this review is to provide an up-to-date review on the chemistry and bioactivity of compounds isolated from all kinds of starfish to illustrate the chemodiversity and biological significance of these constituents, along with their geographical distribution where it is discernible.

Bioactive saponins from the fruits of Aesculus pavia L

Continued chemical investigation on the fruits of Aesculus pavia L. resulted in theisolation and identification of two new oleanolic acid saponins, namely vaccaroside A (1) andvaccaroside B (2). The isolated furostanol saponins were evaluated for cytotoxic activity againsthuman normal amniotic and human lung carcinoma cell lines using neutral red and MTT assays.In vitro experiments showed significant cytotoxicity in a dose dependent manner with IC₅₀ valuesin the range of 27.80-79.02 μM.

Deep-sea natural products

This review covers the 390 novel marine natural products described to date from deep-water (>50 m) marine fauna, with details on the source organism, its depth and country of origin, along with any reported biological activity of the metabolites. Relevant synthetic studies on the deep-sea natural products have also been included.

Novel steroidal saponins, Sch 725737 and Sch 725739, from a marine starfish, Novodinia antillensis

Bioassay-guided fractionation of an active fraction from an extract of a marine starfish, Novodinia antillensis, led to the isolation and identification of two new saponins, Sch 725737 (1) and Sch 725739 (2). Compound 1 was identified as the NaV1.8 inhibitor with IC(50) of approximately 9 microM. The purification and the structure elucidation of these two saponins are described.

Are echinoderms of interest to biotechnology?

The huge potential of echinoderms as a so far fairly untapped source of bioactive molecules is described. Examples are presented that show the usefulness of echinoderm-derived molecules for therapeutic application in selected fields of cancer research, in the control of bacterial growth as substances with new antibiotic properties, and finally in the context of technical applications such as antifouling substances. The molecules described here are but the mere beginning of a commercial exploitation of echinoderms and may incite a deeper involvement of biotechnology-oriented research in this material.

Polar steroidal compounds from the far eastern starfish Henricia leviuscula

Five new polar steroids, polyhydroxysterols 2-5 and the glycoside leviusculoside J (7), were isolated, along with the previously known compounds 1, 6, 8, and 9, from the alcoholic extract of the Far Eastern starfish Henricia leviuscula. The structures of novel compounds were elucidated by interpretation of spectral data (mainly 2D-NMR), and the stereochemistry of chiral centers in the side chain of sterols 2 and 3 was determined by using J-based configuration analysis and the modified Mosher's method. Steroids 1, 3, 6, 7, and 9 showed moderate hemolytic activity in the mouse erythrocytes assay.

Bioactive sterols from the starfish Certonardoa semiregularis

Thirteen new polyhydroxysterols (1-5, 7-12, 14, 15) and two known polyhydroxysterols (6, 13) were isolated from the brine shrimp active fraction of the starfish Certonardoa semiregularis. The structures were determined on the basis of spectral analysis and chemical derivatization. These compounds displayed considerable cytotoxicity against a small panel of human solid tumor cell lines. These compounds were also evaluated for antibacterial activity against 20 clinically isolated strains. Most of the compounds showed weak antibacterial activity against Streptococcus pyogenes 308A, Pseudomonas aeruginosa 1771, and Pseudomonas aeruginosa 1771M.

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

Ten new steroidal sulfates, acanthosterol sulfates A-J (1-10), have been isolated from a marine sponge, Acanthodendrilla sp., collected in western Japan. Acanthosterol sulfates I and J (9 and 10) showed antifungal activity against the yeast Saccharomyces cerevisiae A364A and its mutants at 0.1 mg/disk.