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Three new Δ(1) -3-ketosteroids characterized with a 9-OH, subergosterones A-C (1-3), together with five known analogs 4-8, were obtained from the gorgonian coral Subergorgia rubra collected from the South China Sea. The structures of 1-3, including their absolute configurations, were determined by comprehensive spectroscopic methods and electronic circular dichroism (ECD) experiments. Compounds 2 and 3 exhibited inhibitory antibacterial activities against Bacillus cereus with MIC values of 1.56 μM., (Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.)

Two series of novel steroidal spiro-pyrrolidinyl oxindoles 3a-t and 6a-c were designed and synthesized from dehydroepiandrosterone using the 1,3-dipolar cycloaddition as the key step and further evaluated for their antiproliferative activities for four human cancer cell lines (MGC-803, EC109, SMMC-7721 and MCF-7). This protocol achieved the formation of two CC bonds, one CN bond and the creation of one new five-membered pyrrolidine ring and three contiguous stereocenters in a single operation. Biological evaluation showed that these synthesized steroidal spiro-pyrrolidinyl oxindoles possessed moderate to good antiproliferative activities against the tested cell lines and some of them were more potent than 5-Fu. Particularly, compound 3g showed good antiproliferative activity against SMMC-7721 (IC50=0.71μM). Steroid dimer 6b showed improved antiproliferative activities against SMMC-7721 and MCF-7 with the IC50 values of 4.30 and 2.06μM, respectively. Flow cytometry analysis demonstrated that compound 3n caused the cellular early apoptosis and cell cycle arrest at G2/M phase in a concentration- and time-dependent manner. [Corrected], (Copyright © 2014 Elsevier Ltd. All rights reserved.)

A new diketosteroid, (E)-stigmasta-24(28)-en-3,6-dione (1), along with three known steroids (2-4) was isolated from marine alga Tydemania expeditionis collected in China Sea. Their structures were elucidated by extensive spectroscopic methods. Comparison of the chemical constituents revealed significant diversity among different locations. The biological activities of 1, 3 and 4 were evaluated on the prostate cancer cell lines and androgen receptor. Compound 1 exhibited moderate inhibitory activities against the prostate cancer cells DU145, PC3 and LNCaP with IC(50) values of 31.27±1.50, 40.59±3.10 and 19.80±3.84 μM, respectively. Compound 3 showed more potent activities with IC(50) values of 12.38±2.47, 2.14±0.33 and 1.38±0.07 μM, respectively. However, compound 4 showed only weak inhibitory activities on LNCaP cells and was inactive on DU145 and PC3 cells. A competitive binding assay showed that compound 1 exhibited significant affinity to the androgen receptor with an IC(50) value of 7.19±0.45 μM, while 3 and 4 were inactive. The fact that the inhibitory properties of 1 and 3 against the prostate cancer cells were inconsistent with their affinities to the androgen receptor suggested that there might be other mechanism of action involved in the cytotoxic activity., (Copyright © 2012 Elsevier B.V. All rights reserved.)

A new ketosteroid, 6β,16β-dihydroxycholest-4-en-3-one (1), in addition to the known 6β-hydroxycholest-4-en-3-one (2), 6β-hydroxycholest-4,22-dien-3-one (3) and 16β-hydroxy-5α-cholestan-3,6-dione (4), was isolated from the red alga Jania adhaerens. The structures were assigned on the basis of (1)H- and (13)C-NMR experiments. The new compound (1) was evaluated for its genotoxic and cytotoxic activities and found to possess protective antigenotoxicity in human peripheral blood cells.

(22E)-3beta-Hydroxysitosta-5,22-dien-7-one, (22R, 23R)-3beta,22,23-trihydroxysitost-5-en-7-one, and (22R, 23R)-3beta-hydroxy-22,23-isopropylidenedioxysitost-5-en-7-one were synthesized. The cytotoxicity and effects on cholesterol biosynthesis of the resulting 7-ketosterols, 7-ketocholesterol, and (22S,23S)-3beta-hydroxy-22,23-oxidositost-5-en-7-one were studied in hepatoblastoma Hep G2 cells.

In response to environmental and dietary cues, the C. elegans orphan nuclear receptor, DAF-12, regulates dauer diapause, reproductive development, fat metabolism, and life span. Despite strong evidence for hormonal control, the identification of the DAF-12 ligand has remained elusive. In this work, we identified two distinct 3-keto-cholestenoic acid metabolites of DAF-9, a cytochrome P450 involved in hormone production, that function as ligands for DAF-12. At nanomolar concentrations, these steroidal ligands (called dafachronic acids) bind and transactivate DAF-12 and rescue the hormone deficiency of daf-9 mutants. Interestingly, DAF-9 has a biochemical activity similar to mammalian CYP27A1 catalyzing addition of a terminal acid to the side chain of sterol metabolites. Together, these results define the first steroid hormones in nematodes as ligands for an invertebrate orphan nuclear receptor and demonstrate that steroidal regulation of reproduction, from biology to molecular mechanism, is conserved from worms to humans.

The new (20R)-22E-cholesta-4,22-diene-3,6-dione (1), along with three known 3-keto steroids were isolated from the deep-water Mediterranean scleractinian coral Dendrophyllia cornigera (2-4). Moreover, four known related 3-keto steroids were isolated from the sea grass Cymodocea nodosa (5-8). The structure elucidation of steroid 1 and the full NMR resonance assignments of all isolated metabolites were based on interpretation of their spectral data. All compounds are reported for the first time as metabolites of the investigated organisms. Compounds 2 and 3 showed significant cytotoxicity against lung cancer NSCLC-N6 cell line.

Epidemiologic data suggest a relationship between dietary intake of phytochemicals and a lower incidence of some cancers. Modulation of steroid hormone metabolism has been proposed as a basis for this effect. It has been shown that aromatase, 3beta-hydroxysteroid dehydrogenase and 17beta-hydroxysteroid dehydrogenase (17beta-HSD) are inhibited by the isoflavones, genistein and daidzein, and by coumestrol. In general, the extent of inhibition has been expressed in terms of IC50-values, which do not give information as to the pattern of inhibition, i.e., competitive, non-competitive, or mixed. Less is known of the effects of these compounds on 3alpha-HSD. The human lung is known to have a high level of 17beta-HSD and 3alpha-HSD activity. During the course of studies to characterize both activities in normal and inflamed lung and lung tumors we noted that 3alpha-HSD activity with 5alpha-DHT of microsomes from normal, adult lung was particularly susceptible to inhibition by coumestrol. To clarify the pattern of inhibition, the inhibition constants Ki and K'i were evaluated from plots of 1/v versus [I] and [S]/v versus [I]. Genistein, daidzein and coumestrol gave mixed inhibition patterns versus both 5alpha-DHT and NADH. In contrast, 5alpha-androstane-3,17-dione and 5alpha-pregnane-3,20-dione were competitive with 5alpha-DHT. NAD inhibited competitively with NADH. Our findings demonstrate that phytochemicals have the potential to inhibit 5alpha-DHT metabolism and thereby affect the androgen status of the human lung. The observation of a mixed inhibition pattern suggests these compounds bind to more than one form of the enzyme within the catalytic pathway.

Dexamethasone (Dex) is a potent and long-acting glucocorticoid in terms of anti-inflammatory activity without substantial sodium retaining effect. Here, we examine the ability of the 11beta-hydroxyglucocorticoids Dex and cortisol and their 11-keto forms 11-ketodexamethasone (11-ketoDex) and cortisone to bind to glucocorticoid receptors (GR) and mineralocorticoid receptors (MR) and to mediate nuclear translocation and transactivation of a reporter-gene. Unlike cortisone, the 11-ketosteroid 11-ketoDex acts as a potent GR agonist, comparable to Dex and cortisol. Transactivation of MR by Dex or 11-ketoDex was weak or undetectable, despite efficient binding and induction of nuclear translocation. 11beta-HSD2 protects MR and GR from inappropriate occupation by cortisol; it is, however, unable to prevent activation of GR by 11-ketoDex. The finding that 11-ketoDex is a specific GR agonist may explain the potent glucocorticoid effect of Dex in tissues expressing 11beta-HSD2 including kidney and colon and also in certain tumor cells.

The dichloromethane/methanol extract from the red alga Hypnea musciformis exhibited PPE elastase inhibition. A diketosteroid, the 20-hydroxy-5alpha-cholest-22-ene-3,6-dione was responsible for this activity. Two new steroids were isolated, 2 was assigned as the 6alpha-hydroxy-cholest-4-ene-3-one and 3 as the 6alpha-hydroxy-cholest-4,22-diene-3-one. The structures were assigned mainly on the basis of 1H and 13C NMR experiments.

Mer-NF8054X is a new type of steroid whose structure has been established as 11-oxo-18, 22-cycloergosta-6, 8(14)-diene-3beta, 5beta, 9beta, 23S-tetraol (an 18, 22-cycloergostane), which has been reported to have antifungal activity against Aspergillus fumigatus. However, other biological activities are unknown. Herein, we reported that Mer-NF8054X inhibited cell growth of HL60 human leukemia cells, when used either singly or in combination with retinoic acid (RA). In addition, Mer-NF8054X alone induced differentiation and apoptosis of HL60 cells. The induction of differentiation of HL60 cells by Mer-NF8054X was synergistic in combination with RA. On the other hand, Emesterone A, an analogue of Mer-NF8054X which is missing a hydroxy residue from the third position, showed much lower activity than Mer-NF8054X on the inhibition of cell growth and the induction of cell differentiation and apoptosis. However, Emesterone B, an analogue of Emesterone A which is missing a hydroxy residue from the fifth position, showed higher activity than Emesterone A but lower activity than Mer-NF8054X when examined for the inhibition of cell growth and the induction of cell differentiation and apoptosis. These results suggested that Mer-NF8054X and its analogs may be a new type of differentiation inducing agent. The hydroxy residue at the third position or fifth position in Mer-NF8054X may be necessary, but not essential, for inhibition of growth and induction of both differentiation and apoptosis of HL60 cells. In addition, Mer-NF8054X enhanced the differentiation of HL60 cells induced by RA. Based on these results, Mer-NF8054X may have utility in the clinic in combination with RA for leukemia patients., (Copyright 1998 Academic Press.)

Some 4-fluorinated analogues of 3-oxo-delta 4 steroids and 4-cyano derivatives of progesterone and androstenedione were evaluated as inhibitors of steroid 5 alpha-reductase activity. Inhibitors of this enzyme may be useful in treating prostatic cancer. 4-Fluoroandrostenedione was a modest inhibitor of the rat enzyme (IC50 = 4.08 microM), while 4-cyanoprogesterone was a potent inhibitor of both the rat and human enzymes (IC50 values = 0.045 microM and 0.050 microM respectively). These two steroids were tested in vivo for activity against androgen sensitive organs in WHT mice. 4-Fluoroandrostenedione caused increases in organ weights, suggesting it is an androgen agonist, while the 4-cyano compound displayed modest androgen ablation. Therefore substitutions at the 4-position may produce compounds of therapeutic use in treating prostate cancer.

The properties of 5-ene-3 beta hydroxysteroid oxidoreductase (3 beta-HSD) from human placental homogenates were studied in vitro. The apparent Michaelis constants for 3 beta-HSD with the substrates pregnenolone (delta 5P) and dehydroepiandrosterone (DHA) were 170 nM and nM respectively. The optimal pH for both these substrates was between 10 and 12. With NAD as the substrate, the Km for the pregnenolone was 20 microM and for DHA, 17 microM. The activity of 3 beta-HSD was inhibited by various steroids. Competitive inhibitors (pregnenolone substrate) included: ethynylestradiol (inhibition constant Ki=7.3 nM), DHA (Ki=46 nM), estradiol-17 beta (Ki=46 nM), cholesterol (Ki=0.68 microM) and 16 alpha-hydroxydehydroepiandrosterone (16 alphaOHDHA) (Ki=2.2 microM). When the substrate was DHA, competitive inhibition occurred with the following steroids: ethynylestradiol (Ki=6.4 nM), estradiol-17 beta (Ki=69 nM), pregnenolone (Ki=91 nM), cholesterol (Ki=1.3 microM) and 16 alphaOHDHA (Ki=1.9 microM). 4-Ene-3-ketosteroids such as androstenedione, progesterone (delta 4P), norethindrone and chlormadinone acetate acted as noncompetitive inhibitors towards both substrates.

Two new synthetic steroid analogues, (I) 16beta-bromo-3beta,17alpha-dihydroxy-5alpha-pregnane-11,20-dione and (II) 17beta-ureido-1,4-androstadien-3-one have been shown to give kinetic patterns consistent with active-site-directed irreversible inhibition of adult rat testicular microsomal steroid 17alpha-hydroxylase and C17-20 lyase in vitro. Administration of both analogues to adult male rats for 24 h produced potent inhibition of these testicular enzymes in vivo. Given to pregnant rats during the critical period of male organogenesis they produced hypospadias: a characteristic of the syndrome in man in which these enzymes are defective genetically. Given to male rat pups during the first 9 days of life, inhibitor II produced significantly smaller prostates and seminal vesicles in adulthood, indicating the usefulness of this inhibitor in studies on the role of testosterone in neonatal programming of target organ size in adulthood. Thus, two new enzyme inhibitors have been shown to block testosterone production in the foetal and neonatal rat selectively at the site of the hydroxylase without other apparent hormonal effects or influence on adrenal size.

The responsiveness of seminal vesicles and coagulating gland to androgen-induced growth at adulthood is enhanced in male rats that had been "primed" with androgen (either endogenous or exogenous) during the neonatal period. The neonatal "priming," however, did not significantly affect the basal (unstimulated) wet weights or DNA contents of the sex accessory glands when assessed at adulthood. In contrast to seminal vesicles and coagulating gland, the responsiveness of ventral prostate to the adult androgen-induced growth is independent of neonatal exposure to either endogenous or exogenous androgen. Our studies indicate that the neonatal androgen-induced "priming" or "programming" for androgen sensitivity of sex accessory glands at adulthood may not be associated with DNA synthesis as elicited by androgen during the neonatal period. For example, xyproterone acetate, an antiandrogen, effectively blocked the DNA synthesis in the seminal vesicles and coagulating gland of the neonatal rats without affecting the neonatal "priming" of the responsiveness of these glands at adulthood. Although only seminal vesicles and coagulating gland but not ventral prostate are "programmed" by neonatal exposure to androgen, this androgen-induced enhancement of [3-H]thymidine incorporation in to the DNA of the former was to the same degree as the latter. Furthermore, pulse-labeled cells in all of these glands studied persisted to adulthood to the same extent.

The importance of steric factors in quantitative structure-activity relationships involving steroid hormones is discussed. a variety of steric parameters, such as parachlor, molecular volume, van der Waals volume, and including difference and squared steric terms, is explored in an attempt to find preferred forms for such expressions. Improved correlations for 6-substituted 16-methylene-17alpha-acetoxy-4,6-pregnadiene-3,20-dione derivatives were found in which activity is related to pi and a squared or difference steric factor. The activity of 9alpha-substituted cortisols correlates well with sigma I and a simple steric factor, provided that the 9alpha-hydroxylated compound is excluded from the series.

Basing on the data of the X-ray analysis of 2 beta-methylestr-4,9-dien-3-one-17 beta-ol (C19H26O2) and A-ring unsubstituted steroid 4,9-dien-3-ones, the noncomplanarity and flexibility of the conjugated dienone system in these transformed steroids has been demonstrated. The results have been also confirmed by UV spectroscopy. The ability of the dienone system to assume conformations with the out of- plane C3 = O3 and/or C9 = C10 bonds allows the AB-fragment of the steroid molecule to adopt the conformations required for interacting with various receptors. This property may also account for a simultaneous enhancement of several hormonal activities upon such a modification of steroids. The results of the X-ray analysis of 2 beta-methylestra-4,9-dien-3-one-17 beta-ol (space group P2(1)2(1)2(1), a 8,543(2), b 9,783(2), c 18,690(7) A, R 8,7%) are presented.

Experiments on thymocyte culture of adrenalectomized rats were made to study the effect of 50 transformed steroid compounds containing delta 4-3-keto or delta 5-3-hydroxygroup in ring A, oxygen-containing substituents in ring D and superstructed 20-keto-side chain on glucocorticoid and antiglucocorticoid effects and steroid-receptor interaction. Ten compounds given in a concentration of 10(6) M competed with 3H-triamcinolon for binding thymocyte cytosol on glucocorticoid receptors. Steroid compounds containing the delta 4-3-ketogroup inhibit more actively the incorporation of 3H-uridine into RNA in a concentration of 10(6) M, as compared with compounds containing the delta 5-3-hydroxygroup. Antiglucocorticoid effect on thymocyte function is also produced by 16,17 alpha-isopropylidenedioxy-pregn-5-en-20-on-3 beta-ol; 16,17 alpha-isopropylidenedioxy-pregna-5,21 (21a)-dien-20-on-3 beta-ol at a concentration of 10(6) M.

When two different inhibitors, which are unrelated in structure, inhibit transport by binding to the carrier on the same side of the membrane, it is important for an understanding of the mechanism to decide whether they add to a single common site or to two separate sites. To help resolve this problem, kinetic tests are described for determining whether the inhibitors compete with one another. The test involves measuring the inhibition produced by the inhibitors when acting alone or together. The rate observed with both inhibitors present is then compared with that predicted from the separate inhibitions, for the case of either one or two inhibition sites. The test is applied to the inhibition of glucose transport in erythrocytes by cytochalasin B and the steroids androstenedione and androstanedione. These inhibitors were previously shown to bind to sites which are distinct from the substrate site and which are only present in the inward-facing form of the carrier. Cytochalasin B is now found to compete with the steroids. This finding, together with the earlier evidence that both inhibitors sterically protect the carrier against reaction with fluorodinitrobenzene, leads us to conclude that a single site binds both types of inhibitor.

15-Ketoprogesterone is as active as spironolactone in blocking the mineralocorticoid effect of deoxycorticosterone acetate. This activity is reduced when a methylene group is attached to the 6beta, 7beta position. The title compound was prepared from 15alpha-acetoxy-6-dehydroprogesterone. Methylenation of the delta6 double bond with dimethyloxosulfonium methylide proceeds steroselectively from the beta side of the molecule.

Intrauterine devices (IUD's) containing 0, 5, or 10 per cent by weight of progesterone, melengestrol acetate (MGA), norethindrone, norgestrel, medroxyprogesterone acetate, isoxsuprine, or R2323 or wound with fine copper wire were placed in one or both horns of cycling female rats. All the progestins improved retention of the silicone-rubber IUD's to some degree. The effects of these compounds on the estrous cycle, mating, ovulation, fertilization, tubal transport, and implantation varied among the compounds. Effects were local or systemic, depending upon the amount and the drug. Uterine motility studies showed clearly that 5 per cent MGA decreased uterine motility; however, no consistent results could be obtained using the other compounds in the same in vivo system.