Polyhydroxylated Sterols Research Articles

Integration of virtual screening of phytoecdysteroids as androgen receptor inhibitors by 3D-QSAR Model, CoMFA, molecular docking and ADMET analysis: An extensive and interactive machine learning

Ecdysteroids, a class of naturally isolated polyhydroxylated sterols, stands at a very good place in the pharmaceutical industry from their medicinal point of views like anti-inflammatory, neuroprotective, anti-microbial, anti-diabetic, antioxidant, and anti-tumor effects. Due to their excellent antioxidant and anti-microbial potential, ecdysteroids have extensive use in skin products, especially derma creams. To monitor the best anti-acne phytoecdysteroids, here made use of different computational approaches, by using the rapid, easy, cost-effective and high throughput method to screen and identify ecdysteroids as androgen receptor inhibitors. 3D-QSAR study was carried out on a dataset of ecdysteroids by using comparative molecular field analysis (CoMFA) to determine the factors responsible for the activity of compounds. Statistically a cross-validated (q2) 0.1457 and regression coefficient (r2) 0.9713 indicated the best model. Contour map results showed the influence of steric effect to enhance activity. A molecular docking analysis was done to further find out the binding sites and their anti-acne potential against three crystal structured macromolecules (PDB ID: 2REQ, 2BAC, 4EM0). Docking results were further evaluated by prime MM-GBSA analysis and findings confirmed the accuracy. Toxicity by ADMET assessment was carried out and M2 was found as lead druglike with best anti-acne activity against Propionium acnes GehA lipase bacteria after passing all filters. This research study is novel because it is representing first effort to explore ecdysteroids class for their high therapeutic output as androgen receptor inhibitor by using computational tools and expectedly led to novel scaffold for androgen receptor inhibitor. This is a novel and new approach to investigate the ecdysteroids for first time for their practical applications.

Chemical constituents from starfish Culcita novaeguineae

Seven polyhydroxylated steroidal glycosides (1–7) and two polyhydroxylated sterols (8, 9) were isolated and identified from the 75% ethanol extract of starfish Culcita novaeguineae which was collected in Xisha Islands of South China Sea. The structures of the isolated compounds were elucidated on the basis of spectroscopic data, physical and chemical evidence, MS spectrum and assisted by comparison with the reported data. To the best of our knowledge, this is the first time to report compounds 1–6, 8 and 9 from genus Culcita. Moreover, compounds 1, 4–6, 8 and 9 were isolated from family Oreasteridae for the first time. And the chemotaxonomic significance of the isolated compounds was discussed.

Polyhydroxylated sterols from Monascus purpureus-fermented rice

Using a cell-based cytotoxicity assay, two new polyhydroxylated sterols, 16(S),22(S)-epoxy-3β,5α,6β,20(R),23(R),25-hexahydroxy-7-ergostene and 3β,7β,8α,25-tetrahydroxy-5,22E-ergostadiene were isolated from the ethyl acetate portion of the ethanolic extract of Monascus purpureus. Their structures were elucidated by spectroscopic analysis and in comparison with those reported in the literature. Both compounds showed cytotoxic activity against the lung adenocarcinoma (A549) with IC50 values of 12.6 and 18.5 μM, exhibited moderate activities against human ovarian cancer (A2780), with IC50 values of 8.8 and 9.4 μM.

Two New Polyhydroxylated Sterol Derivatives from the Sponge Topsentia sp. Collected from the South China Sea

Further chemical investigation of the marine sponge Topsentio sp. collected from the South China Sea led to the isolation of two new polyhydroxylated sterol derivatives, topsensterol D (1) and 4β-hydroxyhalistanol (2). Their structures were elucidated by detailed analysis of the spectroscopic data including 1D and 2D NMR spectral data. Their cytotoxic activities were evaluated.

Topsensterols A-C, Cytotoxic Polyhydroxylated Sterol Derivatives from a Marine Sponge Topsentia sp.

Three new polyhydroxylated sterol derivatives topsensterols A–C (1–3) have been isolated from a marine sponge Topsentia sp. collected from the South China Sea. Their structures were elucidated by detailed analysis of the spectroscopic data, especially the NOESY spectra. Topsensterols A–C (l–3) possess novel 2β,3α,4β,6α-tetrahydroxy-14α-methyl Δ9(11) steroidal nuclei with unusual side chains. Compound 2 exhibited cytotoxicity against human gastric carcinoma cell line SGC-7901 with an IC50 value of 8.0 μM. Compound 3 displayed cytotoxicity against human erythroleukemia cell line K562 with an IC50 value of 6.0 μM.

SILAC-Based Mass Spectrometry Analysis Reveals That Epibrassinolide Induces Apoptosis via Activating Endoplasmic Reticulum Stress in Prostate Cancer Cells.

Epibrassinolide (EBR) is a polyhydroxylated sterol derivative and biologically active compound of the brassinosteroids. In addition to well-described roles in plant growth, EBR induces apoptosis in the LNCaP prostate cancer cells expressing functional androgen receptor (AR). Therefore, it is suggested that EBR might have an inhibitory potential on androgen receptor signaling pathway. However, the mechanism by which EBR exerts its effects on LNCaP is poorly understood. To address this gap in knowledge, we used an unbiased global proteomics approach, i.e., stable-isotope labeling by amino acids in cell culture (SILAC). In total, 964 unique proteins were identified, 160 of which were differentially expressed after 12 h of EBR treatment. The quantification of the differentially expressed proteins revealed that the expression of the unfolded protein response (UPR) chaperone protein, calreticulin (CALR), was dramatically downregulated. The decrease in CALR expression was also validated by immunoblotting. Because our data revealed the involvement of the UPR in response to EBR exposure, we evaluated the expression of the other UPR proteins. We demonstrated that EBR treatment downregulated calnexin and upregulated BiP and IRE1α expression levels and induced CHOP translocation from the cytoplasm to nucleus. The translocation of CHOP was associated with caspase-9 and caspase-3 activation after a 12 h EBR treatment. Co-treatment of EBR with rapamycin, an upstream mTOR pathway inhibitor, prevented EBR-induced cell viability loss and PARP cleavage in LNCaP prostate cancer cells, suggesting that EBR could induce ER stress in these cells. In addition, we observed similar results in DU145 cells with nonfunctional androgen receptor. When proteasomal degradation of proteins was blocked by MG132 co-treatment, EBR treatment further induced PARP cleavage relative to drug treatment alone. EBR also induced Ca2+ sequestration, which confirmed the alteration of the ER pathway due to drug treatment. Therefore, we suggest that EBR promotes ER stress and induces apoptosis.

New polyhydroxylated sterols from Palythoa tuberculosa and their apoptotic activity in cancer cells

The chemical study on the total extract of the zoanthid Palythoa tuberculosa, collected from the Red Sea, resulted in the isolation of seven polyhydroxylated sterols (1–7), six of which, palysterols A–F (2–7), are new. Their chemical structures were elucidated on the basis of extensive analysis of their 1-, 2D NMR and MS spectroscopic data. This is the first chemical investigation on the species collected from Red Sea. We studied the cytotoxic effects of the total extract and some of the new polyhydroxylated sterols in three human cancer cell lines (MCF-7, HeLa, and HT-29) and one non-cancerous human cell line (KMST-6). Palysterol F (7), in particular, was able to selectively induce high levels of apoptosis (>75%) in breast adenocarcinoma (MCF-7) cells but not HeLa, HT-29 and KMST-6 cells.

Polyhydroxylated Sterols from the South China Sea Gorgonian Verrucella umbraculum

AbstractTwo new polyhydroxylated sterols, named verumbsteroids A and B (1 and 2, resp.), along with seven known analog, 3–9, were isolated from the gorgonian Verrucella umbraculum collected from the South China Sea. The structures and relative configurations of the new compounds were elucidated by comprehensive spectroscopic investigations. The absolute configuration of 1 was determined by using modified Mosher method with the acetonide derivative of 1. Compounds 1 and 3–5 were found to show cytotoxicities against five human tumor cell lines (HL‐60, K562, HeLa, A‐549, and HCT‐116) with the IC50 values ranging from 2.76 to 9.62 μM.

Bioactive polyhydroxylated sterols from the marine sponge Haliclona crassiloba

Four new polyhydroxylated sterols, named halicrasterols A–D (1–4), together with six known analogs (5–10) were isolated from the marine sponge Haliclona crassiloba. Compounds 1 and 2 represented rare examples of steroids featuring 17(20)E-double bonds. The structures of 1–10 were elucidated by spectroscopic analysis and comparison with reported data. This is the first report of a steroid profile for this species. The antimicrobial activities of 1–10 were evaluated against a panel of bacterial and fungal strains in vitro, and compounds 4 and 9 showed moderate activity against some of the Gram-positive strains with MICs ranging from 4 to 32μg/mL.

Biosynthesis of polar steroids from the Far Eastern starfish Patiria (=Asterina) pectinifera. Cholesterol and cholesterol sulfate are converted into polyhydroxylated sterols and monoglycoside asterosaponin P1 in feeding experiments

For the first time, it is experimentally established that the dietary cholesterol and cholesterol sulfate are biosynthetic precursors of polyhydroxysteroids and related low molecular weight glycosides in starfishes. These deuterium labeled precursors were converted into partly deuterated 5α-cholestane-3β,6α,7α,8,15α,16β,26-heptaol, 5α-cholestane-3β,4β,6α,7α,8,15β,16β,26-octaol, and steroid monoside asterosaponin P1 in result of feeding experiments on the Far Eastern starfish Patiria (=Asterina) pectinifera. The incorporations of deuterium were established by MS and NMR spectroscopy. Scheme of the first stages of biosynthesis of polar steroids in these animals was suggested on the basis of inclusion of three from six deuterium atoms and determination of their positions in biosynthetic products, when [2,2,3,4,4,6-2H6]cholesterol 3-sulfate was used as precursor. It was also shown that labeled cholesterol is transformed into Δ7-cholesterol (lathosterol) in digestive organs and gonads of the starfish.

Fomentarols A–D, sterols from the polypore macrofungus Fomes fomentarius

Four (1-4) hitherto unknown and seven (5-11) known ergostane-type sterols were isolated from the EtOH extract of the dried fruiting bodies of the polypore macrofungus Fomes fomentarius. On the basis of spectroscopic analysis, the structures of polyhydroxylated sterols 1-4 were elucidated to be (22E,24R)-3β,5α,6β,14α-tetrahydroxyergosta-7,9(11),22-triene (fomentarol A, 1), (22E,24R)-3β,5β,6α,7α-tetrahydroxy-8α,9α-dihydroergosta-14,22-diene (fomentarol B, 2), (22E,24R)-3β,5α-dihydroxy-6β-ethoxyergosta-7,22-diene (fomentarol C, 3), and (22E,24S)-3β,25-dihydroxy-15α-O-β-D-glucopyranosylergosta-7,22-dien-6-one (fomentarol D, 4), respectively. Rings A/B and B/C are in turn cis-fused in compound 2, which is uncommon in natural ergostane-type sterols. The potential biogenetic relationship of 2 and other ergostane-type sterols isolated from F. fomentarius was briefly discussed. Moderate cytotoxic effects of the isolated sterols against a small panel of human cancer cell lines were also established.

New polyhydroxy sterols from the marine sponge Callyspongia fibrosa (Ridley & Dendly)

Four new polyhydroxylated sterols are isolated from Marine sponge Callyspongia fibrosa collected from the Gulf of Mannar, western Bay of Bengal (India). The structural assignment is based on 1H and 13C NMR spectra. All sterols are based on the known 24S-24-methyl cholesterol 1 which is also isolated, and contain 3β,6β-dihydroxy system and 25-O-acetate as common features (except in the case of sterol 6 that has a Δ25 in the place of 25-OAc). Additional OH substitution is also present at 5α in 4a and at 8β in 5. A further 12β-OH is present in 6 and 7. The hydroxylation pattern is so far known only in coral sterols but is without a precedent in sponge sterols. The major steroid 4a showed antimalarial activity against Plasmodium falciparum on the chloroquine-resistant stain better than on the chloroquine-sensitive strain.

Complete 1H and 13C NMR assignments of three new polyhydroxylated sterols from the South China Sea gorgonian Subergorgia suberosa

Three new polyhydroxylated sterols, 3beta,6alpha,11,20beta,24-pentahydroxy- 9,11-seco-5alpha-24-ethylcholest-7,28-diene-9-one (1), 3-(1',2'-ethandiol)-24- methylcholest-8(9),22E-diene-3beta,5alpha,6alpha,7alpha,11alpha-pentaol (2), 24-methylcholest-7,22 E-diene-3beta,5alpha,6beta,25-tetraol (3) together with five known sterols, were isolated from the EtOH/CH2Cl2 extract of the South China Sea gorgonian Subergorgia suberosa. The complete assignments of the 1H and 13C NMR chemical shifts for these new compounds were achieved by means of 1D and 2D NMR techniques, including HSQC, HMBC, 1H--1H COSY, and NOESY spectra.

A New 9,11-Secosterol from the Vietnamese Sea Soft Coral, Sarcophyton Mililatensis, Increases the Function of Osteoblastic MC3T3-E1 Cells

Chemical investigation of the Vietnamese soft coral Sarcophyton mililatensis resulted in the isolation of a new 9,11-secosterol, sarcomilasterol (1), along with two known polyhydroxylated sterols, sarcoaldesterol B (2) and ergosta-1β,3β,5α,6β-tetraol (3). Their structures were established on the basis of NMR spectroscopic and MS experiments. Compound 1 (3 μM) significantly increased the growth of MC3T3-E1 cells and caused a significant elevation of alkaline phosphatase activity and nodules mineralization compared to those of the control (P<0.05). These results suggest that compound 1 has a direct stimulatory effect on bone formation in vitro and may contribute to the prevention of osteoporosis.

New Steryl Esters of Fatty Acids from the Mangrove Fungus Aspergillus awamori

AbstractThe polyhydroxylated ergostane‐type sterol 9, its derivatives 10–15, and the fatty acid esters 1–8 were isolated from a fungus strain which was collected from mangrove areas at Wenchang, Hainan Province, P. R. China, exhibited potent cytotoxic activity, and was identified as Aspergillus awamori. The structures of 1–15 were elucidated by spectroscopic and chemical methods. Among them, the six steryl esters 1–6 of fatty acids were new compounds, i.e., (3β,5α,6α,22E)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐palmitate (1), (3β,5α,6α,22E)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐stearate (2), (3β,5α,6α,22E)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐oleate (3), (3β,5α,6α,22E)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐linoleate (4), (3β,5α,6β,22E)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐palmitate (5), and (3β,5α,6β,22E)‐ergosta‐7,22‐diene‐3,5,6‐triol 6‐stearate (6). The related known fatty acids stearic acid (=octadecanoic acid) and palmitic acid (=octadecanoic acid) were also obtained. A speculative biogenetic relationship of the metabolites is proposed. The known polyhydroxylated sterols and derivatives showed cytotoxic activities, in agreement with earlier reports. The cytotoxic activities against B16 and SMMC‐7721 cell lines of the new steryl esters 1–6 by the MTT method were weak.

Epoxidation and reduction of cholesterol, 1,4,6-cholestatrien-3-one and 4,6-cholestadien-3β-ol

Many naturally occurring polyhydroxylated sterols and oxysterols exhibit potent biologic activities. This paper describes reagent and position selectivity of epoxidation and reduction of cholesterol derivatives. Cholesterol was reacted with m-chloroperoxybenzoic acid ( m-CPBA) to form 5α,6α-epoxycholestan-3β-ol, but in reaction with 30% H 2O 2, it did not reacted. 1,4,6-Cholestatrien-3-one was obtained from cholesterol and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone in dioxane. 1,4,6-Cholestatrien-3-one was reacted with 30% H 2O 2 and 5% NaOH in methanol to give 1α,2α-epoxy-4,6-cholestadien-3-one, which was stereoselectively reduced with NaBH 4 to form 1α,2α-epoxy-4,6-cholestadien-3β-ol and reduced with Li metal in absolute ethanol to give 2-ethoxy-1,4,6-cholestatrien-3-one. And 1,4,6-cholestatrien-3-one was epoxidized with m-CPBA in dichloromethane to afford 6α,7α-epoxy-1,4-cholestadien-3-one, which was reacted with NaBH 4 to synthesize 6α-hydroxy-4-cholesten-3-one and reduced Li metal in absolute ethanol to form 2-ethoxy-1,4,6-cholestatrien-3-one, respectively. 1,4,6-Cholestatrien-3-one was reduced with NaBH 4 in absolute ethanol to form 4,6-cholestadien-3β-ol, which was reacted with 30% H 2O 2 to leave original compound, but was reacted with m-CPBA to give 4β,5β-epoxy-6-cholesten-3β-ol as the major product and 4β,5β-epoxy-6α,7α-epoxycholestan-3β-ol as the minor product.

New polyhydroxylated sterols stylisterols A–C and a novel 5,19-cyclosterol hatomasterol from the Okinawan marine sponge Stylissa sp.

New polyhydroxylated sterols, stylisterol A–C ( 1– 3), and a novel 5,19-cyclosterol, hatomasterol ( 4) were isolated from the Okinawan sponge Stylissa sp. Structural determinations of these compounds were made by spectroscopic analysis and chemical conversion. Assessment of cytotoxicity toward HeLa cells was also determined.

IPL576,092, a novel anti-inflammatory compound, inhibits leukocyte infiltration and changes in lung function in response to allergen challenge

IPL576,092, a lead compound from a novel class of polyhydroxylated sterols, was tested in models of allergen-induced bronchoconstriction and airway inflammation. In a rat ovalbumin lung inflammation model, orally administered IPL576,092 significantly inhibited the challenge-mediated increase in total bronchoalveolar lavage leukocyte numbers, and macrophage and lymphocyte infiltration (1–10 mg/kg/day). There was a similar trend towards inhibition of eosinophil and neutrophil accumulation. Sheep were treated with IPL576,092 by inhalation (400 μg/kg/day), and lung resistance and airway hyper-responsiveness (AHR) were determined after Ascaris suum challenge. IPL576,092 significantly reduced the early and late phase bronchoconstrictor responses by 63±4.6 and 84±4.6%, respectively. IPL576,092 also blocked AHR (2.2±5.7% change from pre-challenge PC400), whereas control animals showed a 62.2±2.6% decrease in the PC400 ( p<0.05). Oral IPL576,092 (5 mg/kg/day) also significantly decreased hyper-reactivity in mice. In a guinea pig model, IPL576,092 (5 mg/kg/day) significantly protected against allergen-induced increases in lung resistance (11.4±2.3 control versus 4.8±01.5 IPL576,092, area under the curve) and inhibited the increase in lung elastance (280±58 control versus 167±52 IPL576,092, p<0.05). IPL576,092, unlike dexamethasone, did not significantly decrease rat serum corticosterone levels or thymus and spleen weights, supporting a mechanism of action different from classic glucocorticoids. IPL576,092 significantly attenuates characteristics of an asthmatic response, indicating therapeutic potential for this drug class.

Synthesis of polyhydroxysterols (IV): synthesis of 24-methylene-cholesta-3β,5α,6β,19-tetrol, a cytotoxic natural hydroxylated sterol

The cytotoxic, polyhydroxylated sterol 24-methylene-cholesta-3β,5α,6β,19-tetrol ( 1), previously isolated from the soft corals Nephthea albida and N. tiexieral verseveldt, was synthesized using stigmasterol as the starting material by 10 steps in 9% overall yield. The spectral data and physical constants of 1 were identical with those of the natural product. This is the first report of the synthesis of 1.

Halloween genes encode P450 enzymes that mediate steroid hormone biosynthesis in Drosophila melanogaster

Mutation of members of the Halloween gene family results in embryonic lethality. We have shown that two of these genes code for enzymes responsible for specific steps in the synthesis of ecdysone, a polyhydroxylated sterol that is the precursor of the major molting hormone of all arthropods, 20-hydroxyecdysone. These two mitochondrial P450 enzymes, coded for by disembodied ( dib) (CYP302A1) and shadow ( sad) (CYP315A1), are the C22 and C2 hydroxylases, respectively, as shown by transfection of the gene into S2 cells and subsequent biochemical analysis. These are the last two enzymes in the ecdysone biosynthetic pathway. A third enzyme, necessary for the critical conversion of ecdysone to 20-hydroxyecdysone, the 20-monooxygenase, is encoded by shade ( shd) (CYP314A1). All three enzymes are mitochondrial although shade has motifs suggesting both mitochondrial and microsomal locations. By tagging these enzymes, their subcellular location has been confirmed by confocal microscopy. Shade is present in several tissues as expected while disembodied and shadow are restricted to the ring gland. The paradigm used should allow us to define the enzymes mediating the entire ecdysteroid biosynthetic pathway.