Structure-activity relationships of synthetic progestins in a yeast-based in vitro androgen bioassay

The recent identification of tetrahydrogestrinone (THG), a non-marketed designer androgen used for sports doping but previously undetectable by established mass spectrometry-based urine drug screens, and its production by a facile chemical modification of gestrinone has raised concerns about the risks of developing designer androgens from numerous marketed progestins. We therefore have used yeast-based in vitro androgen and progesterone bioassays to conduct a structure-activity study assessing the intrinsic androgenic potential of commercially available progestins and their derivatives, to identify those compounds or structures with the highest risk of forming a basis for such misapplication. Progestins had a wide range of androgenic bioactivity that was not reliably predicted for individual steroids by their progestin bioactivity. 17alpha-Hydroxyprogesterone and 19-norprogesterone derivatives with their bulky 17beta-substituents were strong progestins but generally weak androgens. 17alpha-Ethynylated derivatives of testosterone, 19-nortestosterone and 18-methyl-19-nortestosterone such as gestrinone, ethisterone, norethisterone and norgestrel had the most significant intrinsic androgenicity of all the commercially marketed progestins. Facile chemical modification of the 17alpha-ethynyl group of each of these progestins produces 17alpha-methyl, ethyl and allyl derivatives, including THG and norbolethone, which further enhanced androgenic bioactivity. Thus by using the rapid and sensitive yeast bioassay we have screened a comprehensive set of progestins and associated structures and identified the ethynylated testosterone, 19-nortestosterone and 18-methyl-19-nortestosterone derivatives as possessing the highest risk for abuse and potential for conversion to still more potent androgens. By contrast, modern progestins such as progesterone, 17alpha-hydroxyprogesterone and 19-norprogesterone derivatives had minimal androgenic bioactivity and pose low risk.

Influence of demographic factors and sport type on growth hormone-responsive markers in elite athletes

CONTEXT

GH-responsive markers of the IGF system and of collagen turnover hold promise as the basis of a GH doping test.

OBJECTIVE

The purpose of this study was to determine the influence of age, gender, body mass index (BMI), ethnicity, and sporting type on GH-responsive serum markers in a large cohort of elite athletes from different ethnic backgrounds.

DESIGN

The study was designed as a cross-sectional study.

PARTICIPANTS

A total of 1103 elite athletes (699 males, 404 females), aged 22.2 +/- 5.2 yr, from 12 countries and 10 major sporting categories participated in this study.

MAIN OUTCOME MEASURES

Serum IGF-I, IGF binding protein-3 (IGFBP-3), acid labile subunit (ALS), and collagen markers [N-terminal propeptide of type I procollagen (PINP), C-terminal telopeptide of type I collagen (ICTP), N-terminal propeptide of type III procollagen (PIIINP)] were measured.

RESULTS

There was a significant negative correlation (r = -0.14 to -0.58, P < 0.0005) between age and each of the GH-responsive markers. Serum IGF-I, IGFBP-3, and ALS were all lower (P < 0.05), whereas the collagen markers PINP, ICTP, and PIIINP were higher (P < 0.05) in men than in women. Multiple regression analysis indicated that age, gender, BMI, and ethnicity accounted for 23-54% of total between-subject variability of the markers. Age and gender cumulatively accounted for 91% of the attributable variation of IGF-I and more than 80% for PINP, ICTP, and PIIINP. Gender exerted the greatest effect on ALS (48%), and BMI accounted for less than 12% attributable variation for all markers. The influence of ethnicity was greatest for IGFBP-3 and ALS; however, for the other markers, it accounted for less than 6% attributable variation. Analysis of 995 athletes indicated that sporting type contributed 5-19% of attributable variation.

CONCLUSIONS

Age and gender were major determinants of variability of GH-responsive markers except for IGFBP-3 and ALS. Ethnicity is unlikely to confound the validity of a GH doping test based on IGF-I and these collagen markers.

Erythropoietin administration does not influence the GH--IGF axis or makers of bone turnover in recreational athletes

OBJECTIVE

Measurement of biochemical markers of the IGF-system and of collagen turnover is a potential approach to detect GH abuse in sport. These markers are increased in patients on dialysis treated with recombinant human erythropoietin (r-HuEPO), mimicking the effects of GH. The aim was to determine whether r-HuEPO induces similar effects on the IGF-system and collagen turnover in healthy athletes.

SUBJECTS AND MEASUREMENTS

Young male Caucasian recreational athletes were administered 50 U/kg r-HuEPO (n=14) or placebo (n=16) three times a week for 25 days, followed by a 4-week wash-out period. IGF-I, IGFBP-3, the acid labile subunit (ALS), N-terminal propeptide of type I collagen (PINP), C-terminal telopeptide of type I collagen (ICTP) and N-terminal propeptide of type III collagen (PIIINP) were measured in samples collected at baseline (two samples), after 10, 22 and 24 days of r-HuEPO treatment and at the end of the 4-week wash-out period.

RESULTS

Treatment with r-HuEPO resulted in approximately threefold elevation of serum EPO and marked elevation of markers of erythropoiesis. There was no significant treatment effect of r-HuEPO compared to baseline on IGF-I, IGFBP-3, ALS, PINP, ICTP or PIIINP.

CONCLUSIONS

r-HuEPO administration did not change markers of the IGF-system and of collagen turnover in young healthy male athletes. Therefore, use of r-HuEPO in athletes should not affect the validity of a GH doping test using these GH-responsive markers.

Searching for new markers of endogenous steroid administration in athletes: “looking outside the metabolic box”

A simple means of detecting the abuse of steroids that also occur naturally is a problem facing doping control laboratories. Specific markers are required to allow the detection of the administration of these steroids. These markers are commonly measured using a set of data obtained from the screening of samples by gas chromatography-mass spectrometry (GC-MS). Doping control laboratories further need to confirm identified abuse using techniques such as gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). An interesting urinary species was found while following the pharmacokinetics and changes to the steroid profile from single and multiple oral doses of the International Olympic Committee/World Anti Doping Agency (IOC/WADA) prohibited substance, dehydroepiandrosterone (DHEA). The urine samples collected from the administration studies were subject to GC-MS and GC-C-IRMS steroid analysis following cleanup by solid phase extraction techniques. A useful urinary product of DHEA administration was detected in the urine samples from each of the administration studies and was identified by GC-MS experiments to be 3alpha,5-cyclo-5alpha-androstan-6beta-ol-17-one (3alpha,5-cyclo). This compound occurs naturally but the concentrations of 3alpha,5-cyclo were elevated following both the single DHEA administration (up to 385 ng/mL) and multiple DHEA administrations (up to 1240 ng/mL), in relation to those observed prior to these administrations (70 and 80 ng/mL, respectively). A reference distribution of urine samples collected from elite athletes (n = 632) enabled the natural concentration range of 3alpha,5-cyclo to be established (0-280 ng/mL), with a mean concentration of 22 ng/mL. Based on this an upper 3alpha,5-cyclo concentration limit of 140 ng/mL is proposed as a GC-MS screening marker of DHEA abuse in athletes. GC-C-IRMS analysis revealed significant 13C depletion of 3alpha,5-cyclo following DHEA administration. In the single administration study, the delta13C value of 3alpha,5-cyclo changed from -24.3 per thousand to a minimum value of -31.1 per thousand at 9 h post-administration, before returning to its original value after 48 h. The multiple administration study had a minimum delta13C 3alpha,5-cyclo of -33.9 per thousand during the administration phase in contrast to the initial value of -24.2 per thousand. Preliminary studies have shown 3alpha,5-cyclo to most likely be produced from DHEA sulfate found at high levels in urine. The complementary use of GC-MS and GC-C-IRMS to identify new markers of steroid abuse and the application of screening criteria incorporating such markers could also be adapted by doping control laboratories to detect metabolites of androstenedione, testosterone and dihydrotestosterone abuse.

124.Tetrahydrogestrinone (THG) is a potent androgen and progestin

Tetrahydrogestrinone (THG) is a novel steroid recently identified by a sports doping laboratory as an illicit agent sold to improve elite athletic performance. While its structure is closely related to gestrinone, a 19-nor progestin, and resembles that of trenbolone, a potent banned synthetic androgen, THG was never marketed, so no information on its hormonal properties are known. We therefore examined THG for steroidal bioactivity using yeast transformed with a steroid receptor-reporter system, comparing its bioactivity to other known androgens, nandrolone, 7α nandrolone (MENT), norbolethone, 5α-norbolethone, norethandrolone and trenbolone, as well as THG's parent compound, gestrinone. Yeast were stably transformed with human androgen receptor (AR) or progesterone receptor A (PR) cDNA, together with a reporter plasmid containing a β-galactosidase gene under the transcriptional control of an androgen (ARE) or progestin (PRE) reporter element. Bioassays were established by culturing transformed yeast in the presence of the steroids over the range of 1.2�×�10–6 to 5.9�–�10–10�M.The bioassay end-point was β-galactosidase activity in yeast cell lysates. THG showed dose-dependent highly potent activation of AR activity with an EC50 of 0.29�nM compared with other steroids nandrolone (0.12�nM), norbolethone (0.3�nM), 5α-norbolethone (0.026�nM), gestrinone (0.59�nM), trenbolone (0.78�nM), norethandrolone (0.19�nM) and MENT (0.01�nM). THG also activated PR (EC50 0.7�nM) with much higher potency than its parent steroid, gestrinone (EC50 30�nM). We conclude that THG is a potent androgen and progestin. It shows similar potency to the comparator androgens, nandrolone, norbolethone, 5α-norbolethone and trenbolone. The discovery of this illicit designer androgen raises concern about the possibility of other novel androgens being produced from other marketed synthetic sex steroids.

Detection of recombinant human erythropoietin abuse in athletes utilizing markers of altered erythropoiesis

BACKGROUND AND OBJECTIVES

The detection of recombinant human erythropoietin (r-HuEPO) abuse by athletes remains problematic. The main aim of this study was to demonstrate that the five indirect markers of altered erythropoiesis identified in our earlier work were reliable evidence of current or recently discontinued r-HuEPO use. A subsidiary aim was to refine weightings of the five markers in the initial model using a much larger data set than in the pilot study. A final aim was to verify that the hematologic response to r-HuEPO did not differ between Caucasian and Asiatic subjects.

DESIGN AND METHODS

Recreational athletes resident in Sydney, Australia (Sydney, n = 49; 16 women, 33 men) or Beijing, China (Beijing, n=24; 12 women, 12 men) were randomly assigned to r-HuEPO or placebo groups prior to a 25 day administration phase. Injections of r-HuEPO (or saline) were administered double-blind at a dose of 50 IU/kg three times per week, with oral iron (105 mg) or placebo supplements taken daily by all subjects. Blood profiles were monitored during and for 4 weeks after drug administration for hematocrit (Hct), reticulocyte hematocrit (RetHct), percent macrocytes (%Macro), serum erythropoietin (EPO) and soluble transferrin receptor (sTfr), since we had previously shown that these five variables were indicative of r-HuEPO use.

RESULTS

The changes in Hct, RetHct, %Macro, EPO and sTfr in the Sydney trial were qualitatively very similar to the changes noted in our previous administration trial involving recreational athletes of similar genetic origin. Statistical models developed from Fisher's discriminant analysis were able to categorize the user and placebo groups correctly. The same hematologic response was demonstrated in Beijing athletes also administered r-HuEPO.

INTERPRETATION AND CONCLUSIONS

This paper confirms that r-HuEPO administration causes a predictable and reproducible hematologic response. These markers are disturbed both during and for several weeks following r-HuEPO administration. This work establishes an indirect blood test which offers a useful means of detecting and deterring r-HuEPO abuse. Ethnicity did not influence the markers identified as being able to detect athletes who abuse r-HuEPO.

Drug testing at the Sydney Olympics

With pre-Olympic and out-of-competition testing, as well as a new, validated test for erythropoietin, athletes will be exposed to more comprehensive drug testing at the Sydney Olympics.

Drugs in sports: analytical trends

A minority of athletes continues to use prohibited drugs in sports to enhance performance. Athletes discovered using these drugs can be subject to severe penalties, often resulting in media and public scrutiny, especially at major events such as the Olympic Games. The International Olympic Committee (IOC) has set out the classes of the substances it bans in the IOC Medical Code. In many cases "old" drugs such as anabolic steroids are still used, and current testing regimes can test for these. Advances in the therapeutic treatment of illness have resulted in new drugs or practices, many of which are difficult to detect and which have been turned to the sinister role of performance enhancement. Detection of some newly developed drugs which have been placed on the banned list offers a major challenge to laboratories involved in sports dope testing. In some cases this requires research into new applications of research techniques. These techniques involve the novel use of gas chromatography/ mass spectrometry (GC/MS) techniques, high-resolution mass spectrometry (HRMS), carbon isotope ratio mass spectrometry, and immunoassay techniques.

Structural analogues of ZAPA as GABAA agonists

Structural analogues of ZAPA, Z-3-[(aminoiminomethyl)thio]prop-2-enoic acid, an isothiouronium analogue of GABA, are potent GABAA agonists as seen in the isolated guinea-pig ileum and in the facilitation of [3H]diazepam binding to rat brain membranes. Compounds with guanidino or amidine groups replacing the amino functionality of GABA were also found to be active. The highest activity was displayed by the isothiouronium salts in which the conformational flexibility of the molecule is restricted by a Z-substituted carbon-carbon double bond. A series of bis-isothiouronium compounds was prepared from aliphatic alpha, omega-bis-thioureas as mixtures of E and Z adducts. Maximum GABAA agonist activity for this series was found with a C6-C8 carbon chain, and the results were consistent with an interaction at the GABAA receptor with only one end of the molecule, rather than the more potent effect expected of a molecule bridging two active sites. GABAA antagonist/partial agonist activity was observed on the guinea pig isolated ileum for a number of different analogue types, with the most potent being bis-isothiouronium derivatives. None of the substituted derivatives of ZAPA was as active as ZAPA itself, and maximum GABAA activity was found in the n-pentyl and n-hexyl analogues.

Gas chromatographic-mass spectrometric quantitation of urinary buprenorphine and norbuprenorphine after derivatization by direct extractive alkylation

A gas chromatographic-mass spectrometric procedure for the quantitation of buprenorphine and norbuprenorphine has been developed in which the analytes were converted, after enzyme hydrolysis, to their methyl derivatives by direct extractive alkylation using tetrahexylammonium hydrogen sulphate phase transfer reagent and iodomethane dissolved in tert.-butylmethyl ether. The procedure utilised a sample volume of 2 ml and gave a detection limit of 0.2 ng ml(-1) for buprenorphine and norbuprenorphine. The buprenorphine and norbuprenorphine standard curves were linear in the concentration range of 1-100 ng ml(-1) with r=0.999. The coefficients of variation for the intra-run precision were 1.3% for buprenorphine and 8.8% for norbuprenorphine (n=10). The coefficients of variation for the inter-run precision were 7.7% for buprenorphine and 10.1% for norbuprenorphine (n=5). The method recovery was 92% (C.V.=3.3%) for buprenorphine and 104% (C.V.=2.9%) for norbuprenorphine (n=10).

Profiling of urinary testosterone and luteinizing hormone in exercise-stressed male athletes, using gas chromatography-mass spectrometry and enzyme immunoassay techniques

Knowledge of the effects of episodic or short-term exercise-stress on endogenous testosterone and luteinizing hormone levels still remains fragmentary and inconclusive. In this study, an approach based on the absolute concentrations of urinary total testosterone (T), luteinizing hormone (LH) and the T/LH concentration ratios, was used to profile short-term exercise-stress responses in healthy drug-free male athletes. Testosterone and luteinizing hormone concentrations were measured using gas chromatography-mass spectrometry (GC-MS) and microparticle enzyme immunoassay (MEIA) techniques, respectively. Stress profiles derived from exercise-stress at VO2max, 68.1% VO2max and 51.6% VO2max were plotted using the concentrations of T, LH and the ratios of T/LH found under non-stressed and stressed conditions. Significant changes in LH concentrations (p < 0.005) and T/LH ratios (p < 0.005) levels were observed between the pre-stress and post-exercise conditions during acute exercise-stress at VO2max but the T concentration did not show any marked change relative to the non-stressed condition. Whilst exercise-stress appeared to reduce the change in T concentrations between the pre- and post-exercise states compared to that in the non-stressed control condition, the change in LH concentrations showed a moderate increase at submaximal oxygen uptake values. The stress profiles derived from this study facilitated an assessment of the relationship between the endogenous T, LH and T/LH ratio stress-responses over a short period of applied exercise-stress.

Gas chromatographic-mass spectrometric quantitation of urinary 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid after derivatization by direct extractive alkylation

A gas chromatographic-mass spectrometric procedure for the quantitation of urinary 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) has been developed in which the THC-COOH was derivatized to its corresponding methyl ester-methyl ether derivative by direct extractive alkylation using tetrahexylammonium (THA+) counter-ion and iodomethane dissolved in toluene. The procedure utilised a sample volume of 2 ml and gave a detection limit of 0.25 ng/ml. The inter-run and intra-run coefficients of variation were 7.0% and 4.8%, respectively. The inter-day standard curves were linear in the concentration range 0-300 ng/ml with a mean r = 0.9997 (n = 4).

Diuretic screening in human urine by gas chromatography-mass spectrometry: use of a macroreticular acrylic copolymer for the efficient removal of the coextracted phase-transfer reagent after derivatization by direct extractive alkylation

A simple and efficient procedure has been developed for the derivatization of diuretic agents in human urine by direct extractive alkylation and their detection by gas chromatography-mass spectrometry. The procedure is an improvement over previous extractive alkylation methods because of the development of a simple clean-up step using a macroreticular acrylic copolymer (SM-7 resin) to remove the coextracted phase-transfer reagent from the organic phase after derivatization. With 1 ml of sample the method gives detection limits in the range 10-50 ng/ml for acetazolamide, probenecid, dichlorphenamide, hydroflumethiazide, furosemide, chlorthalidone, bumetanide, hydrochlorothiazide, quinethazone, bendroflumethiazide, metolazone and cyclopenthiazide.

Routine screening and quantitation of urinary corticosteroids using bench-top gas chromatography-mass-selective detection

A method was developed for the routine screening, confirmation and quantitation of corticosteroids in human urine using bench top capillary gas chromatography (GC)-mass-selective detection. The free and conjugated corticosteroid fractions were isolated by liquid-liquid partition. After evaporation to dryness under vacuum the corticosteroid residues were derivatized to form the methyloxime trimethylsilyl ether derivatives. Both GC retention data and characteristic spectral data based on authentic reference standards were used for the identification and quantitation of cortisol, cortisone, tetrahydrocortisol and tetrahydrocortisone in the ppb (ng/ml) concentration range. The method is simpler and more efficient than the other GC-mass spectrometric (MS) techniques. It is also more sensitive than the liquid chromatographic-MS method.

Screening for diuretics in human urine by gas chromatography-mass spectrometry with derivatisation by direct extractive alkylation

A rapid, sensitive and reliable gas chromatographic-mass spectrometric (GC-MS) screening procedure for diuretics in human urine has been developed. The procedure uses derivatisation by extractive methylation directly from the urine. The suitability of a number of phase transfer reagents and solvents were studied for the detection of sixteen diuretics. The results obtained indicate that the screening procedure employing tetrahexylammonium hydrogensulphate at pH 12 with methyl iodide in toluene at room temperature was the most effective. This method gives selectivity and sensitivities down to 0.03-0.1 microgram/ml and provides a substrate suitable for GC-MS confirmation without further manipulation. The application of the method is demonstrated by the screening of urine for bumetanide, ethacrynic acid, acetazolamide, chlorothiazide and hydrochlorothiazide.

Isothiouronium compounds as gamma-aminobutyric acid agonists

Analogues of gamma-aminobutyric acid (GABA) incorporating an isothiouronium salt as a replacement for a protonated amino functional group have been investigated for activity on: GABA receptors in the guinea-pig ileum; [3H]-GABA and [3H]-diazepam binding to rat brain membranes; and GABA uptake and transamination. For the homologous series of omega-isothiouronium alkanoic acids, maximum GABA-mimetic activity was found at 3-[(aminoiminomethyl)thio]propanoic acid. Introduction of unsaturation into this compound gave two isomeric conformationally restricted analogues. The trans isomer was inactive at GABA receptors while the cis compound ((Z)-3-[(aminoiminomethyl)thio]prop-2-enoic acid (ZAPA)) was more potent than muscimol and GABA as a GABA agonist with respect to low affinity GABA receptor sites. Both isomers were moderately potent at inhibiting the uptake of [3H]-GABA into rat brain slices. Comparison of possible conformations of the two unsaturated isomers by interactive computer graphics modelling and comparison with muscimol has led to a plausible active conformation of ZAPA, which may be a selective and potent agonist for low affinity GABA binding sites.

Synthesis of Analogues of GABA. XIV. Synthesis and Activity of Unsaturated Derivatives of 5-Aminopentanoic Acid (d-Aminovaleric Acid)

The (Z) and (E) pairs of 5-aminopent-2-enoic acid and 5-aminopent-3- enoic acid, as well as the related 5-aminopent-3-ynoic acid, have been prepared for structure-activity studies on GABA receptors. Only the (Z) isomers were active as GABA agonists with (Z)-5-aminopent-2-enoic acid being two- to four-fold more active than 5-aminopentanoic acid.

Synthesis of Analogues of GABA. XIII. An Alternative Route to (Z)-4-Aminocrotonic Acid

(Z)-4-Aminocrotonic acid can be conveniently prepared via crystalline phthalimido protected intermediates.

Halogenated pyrrolopyrimidine analogues of adenosine from marine organisms: pharmacological activities and potent inhibition of adenosine kinase

Two novel halogenated pyrrolopyrimidine analogues of adenosine, isolated from marine sources, have been examined for pharmacological and biochemical activities. 4-Amino-5-bromo-pyrrolo[2,3-d]pyrimidine, from a sponge of the genus Echinodictyum, had bronchodilator activity at least as potent as theophylline but with a different biochemical profile; unlike theophylline it had no antagonist activity at CNS adenosine receptors and it was quite a potent inhibitor of adenosine uptake and adenosine kinase in brain tissue. 5'-Deoxy-5-iodotubercidin, isolated from the red alga Hypnea valentiae, caused potent muscle relaxation and hypothermia when injected into mice. This compound was a very potent inhibitor of adenosine uptake into rat and guinea-pig brain slices and an extremely potent inhibitor of adenosine kinase from guinea-pig brain and rat brain and liver. Neither of these two pyrrolopyrimidine analogues was a substrate for, or an inhibitor of, adenosine deaminase. Neither compound appeared to have any direct agonist activity on guinea-pig brain adenosine-stimulated adenylate cyclase (A2 adenosine receptors). 5'-Deoxy-5-iodotubercidin is unique in two respects: it appears to be the first naturally-occurring example of a 5'-deoxyribosyl nucleoside and is the first example of a specifically iodinated nucleoside from natural sources. It may be the most potent adenosine kinase inhibitor yet described and, by virtue of its structure, may prove to be the most specific.

Halogenated pyrrolo[2,3-d]pyrimidine nucleosides from marine organisms

4-Amino-5-bromopyrrolo[2,3-d]pyrimidine has been isolated from a sponge (Echinodictyum sp.). The pharmacologically active constituent of the red alga Hypnea valendiae has been identified as 4-amino-7-(5'-deoxyribos-1'β-yl)-5-iodopyrrolo[2,3-d]pyrimidine (7). A second nucleoside, tentatively assigned as the 1'α isomer of (7), has also been isolated.

Synthesis of analogues of GABA. IX. 5-(Aminomethyl)-3-hydroxyfuran-2(5H)-one

5-(Aminomethyl)-3-hydroxyfuran-2(5H)-one (4) has been synthesized as a GABA analogue in five steps from hex-3-enedioic acid, the enolic α-keto group being introduced under mild conditions by means of a singlet oxygen cleavage of an enamino lactone. The compound showed negligible activity as a GABA agonist with respect to inhibition of [3H]GABA binding, uptake and trans amination in rat brain membranes

The structure of a diterpene with a new carbocyclic ring skeleton from the soft coral Efflatounaria sp. nov

The structure of a diterpene with a new bicarbocyclic ring skeleton has been solved by analysis of the 400-MHz 1H n.m.r. spectrum, and confirmed by a single-crystal X-ray analysis.

Two new cembrane diterpenes from a soft coral (Sarcophyton species)

Two new cembrane diterpenes, related to sarcophine, have been isolated from a soft coral (Sarcophyton sp.). Structures were solved primarily by spectral methods. The pharmacological profile of one metabolite (5) is briefly discussed.

Two new furans from the brown alga Acrocarpia paniculata: the use of 4-phenyl-4H-1,2,4-triazoline-3,5-dione to determine the substitution pattern of a furan

The dichloromethane-soluble extract of the brown alga Acrocarpia paniculata has yielded two homologous branched chain lipids containing a furan ring. Reaction of a substituted furan with 4-phenyl-4H-1,2,4-triazoline-3,5-dione to yield an alkyl 2-ene-1,4-dione was used to determine the orientation of substituents on a 2,3,5-substituted furan.

Spermidine derivatives and 9,11-secosteroids from a soft coral (Sinularia sp.)

The structures of two new N-methylated spermidine amides, (4) and (5), isolated from a soft coral (Sinularia sp.) are described together with the synthesis of one of them. Two new 9,11-secocholestane derivatives, (6) and (7), have also been isolated from the same organism.

Two cembranes from Cespitularia species (soft coral)

Two new cembranolides, (1R,2S,3E,7R,8R,11E,14S)-7,8-epoxy-14-hydroxycembra-3,11,15-trien-17,2-olide and (lR,2R,3E,7R,SR,11E,14R)-7,8-epoxy-14-hydroxycembra-3,11,15-trien-17,2-olide, have been isolated from separate species of Cespitularia (soft coral).

Five new C26 tetracyclic terpenes from a sponge (Lendenfeldia sp.)

Five new scalarane sesterterpenes have been isolated from a Western Australian sponge (Lendenfeldia sp.). As with earlier reported examples of these compounds, several of these metabolites of this sponge are extremely potent inhibitors of platelet aggregation.

Macrocyclic enol-ethers containing an acetylenic group from the red alga Phacelocarpus labillardieri

Four new acetate-derived metabolites have been isolated from two collections of the red alga Phacelocarpus labillardieri. Three of these metabolites were 2,6-disubstituted pyran-4-ones containing a macrocyclic enol-ether ring. The fourth compound was a 6-substituted pyran-2-one derivative.

A blue pigment from a compound ascidian

A deep blue pigment, isolated from a Western Australian compound ascidian, has been shown to be identical to a tetrapyrrole reported from a mutant strain of a bacterium.

A brominated metabolite from the red alga Vidalia spiralis

3,4-Dibromo-5-methylenecyclopent-3-ene-1,2-diol has been isolated from a Western Australian collection of the red alga Vidalia spiralis.

New furano-sesquiterpenes from the sponge Dysidea herbacea

Eight new sesquiterpenes, (ll), (12), (14)-(16), (18), (20) and (21), have been isolated from four separate small collections of the sponge Dysidea herbacea. The structures of these compounds, all of which contain a furan group, were derived by comparison of their spectral properties with those of known sesquiterpenes.

Studies of Australian soft corals. XXIV. Two cembranoid diterpenes from the soft coral Sinularia facile

Extraction of the soft coral Sinularia facile afforded two cembranoid diterpenes whose structures and absolute configurations have been determined as (1R,4R,2E,7E,11E)-cembra-2,7,11-trien-4-ol (1) and (1R,3S,4S,7E,11E)-3,4-epoxycembra-7,11,15-triene (2).

New metabolites from the brown algal genus Cystophora

The dichloromethane-soluble secondary metabolites of four Cystophora species, C. monilifera, C. congesta, C. expansa and C. scalaris, are described. The structures of two new acyl phloroglucinols isolated from C. monilifera have been established by a combination of spectral and chemical methods.

Brominated tyrosine-derived metabolites from the sponge Ianthella basta

Seven novel metabolites, each originating from four bromotyrosine units, have been isolated from the sponge Ianthella basta. Bastadin-1 (2), bastadin-2(3) and bastadin-3(4) are derived from a single phenol oxidative coupling whilst the macrocyclic compounds bastadin-4(5), bastadin-5(6), bastadin-6(8) and bastadin-7(7) are formed by two phenol oxidative coupling reactions. Compounds (2)-(8) showed potent in vitro antimicrobial activity against Gram-positive organisms.

Terpenoid constituents from two Phyllospongia spp

The structures of six new C26 tetracyclic terpenoids isolated from two Phyllospongia spp. are described. The relative stereochemistry of one compound was solved by a single-crystal X-ray determination.

2-Phenylethylamides of a novel lipid acid; atrial stimulants from the soft coral Sinularia flexibilis

Three amides derived from tyramine, 4-(2-aminoethyl)-2-methoxyphenol and 5-(2-aminoethyl)-2-methoxyphenol and a novel lipid acid, (Z)-3- methyldodec-2-enoic acid, were isolated from the soft coral Sinularia flexibilis. The structures, obtained by spectral methods, were confirmed by synthesis.

New metabolites from the brown alga Caulocystis cephalornithos

The antiinflammatory principle of the brown alga Caulocystis cephalornithos has been shown to be 6-tridecylsalicylic acid. Four other metabolites, 3-tridecylphenol, pentadec-1-ene, (E)-heptadec-3-en- 2-one and 8-hydroxy-3-undecyl-1H-2-benzopyran-1-one were also isolated from the dichloromethane extract of the freeze-dried alga.

A New Series of Diterpenes from Australian Spongia Species

Great Barrier Reef sponges of the genus Spongia have yielded eight closely related tetracyclic furanoditerpenes. The structures, assigned on the basis of spectral methods, have been confirmed by a single-crystal X-ray analysis of one of the metabolites and the relative stereochemical features have been defined. The absolute configuration of this metabolite was determined by circular dichroism, which allowed the relationship between the eight new compounds to be determined.

Studies of Australian soft corals. X. The isolation of epoxyisoneocembrene-A from Sinularia grayi and isoneocembrene-A from Sarcophyton ehrenbergi

The isolation of an epoxyisoneocembrene-A [(E,E,E)-11,12-epoxy-1- isopropyl-4,8,12-trimethylcyclotetradeca-1,3,7-triene] (1), from the soft coral Sinularia grayi, is reported and its structure demonstrated by chemical and spectroscopic means. The isolation of an isomer of the reported cembrene sarcophytoxide (2) and of isoneocembrene-A (3), an isomer of the termite trail pheromone neocembrene-A, from the soft coral Sarcophyton ehrenbergi is also reported. Chemical transformations enabled (1) to be converted into (3).

New quinones from a dictyoceratid sponge

Five new quinones have been isolated from a sponge tentatively classified as Stelospongia conulata. Isospongiaquinone (7) has a rearranged drimane skeleton whereas spongiaquinone (19), cyclo- spongiaquinone-1 (20), cyclospongiaquinone-2 (21) and dehydrocyclospongiaquinone-1 (22) have a normal drimane skeleton. The structures of these were derived from chemical and spectral evidence.