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Three novel sulphated polyhydroxylated steroids, named asterasterols A-C (1-3), have been isolated from an Antarctic starfish of the family Asteriidae and their structures elucidated by spectroscopic studies. Steroid 1 has the seven-membered 5-oxalactone B-ring; 2 and 3 are the corresponding 6-oxo steroids. © 1997 Published by Elsevier Science Ltd. In connection with our systematic investigation of steroid constituents from echinoderms, we examined some Antarctic starfish species, t'2 These studies have led to the isolation of a series of sulfated polyhydroxysteroids and steroidal glycosides structurally very close, some identical, with those found in species collected in warm environments. 3 During the investigation of the polar extracts of an Antarctic starfish of the family Asteriidae, which is the subject of this report, we have isolated a structurally novel steroid exhibiting 7-membered 5- oxalactone B-ring, along with the corresponding 6-oxo steroids. The starfish, Asteriidae family, was collected in Tethis Bay during the Italian-Antarctic expedition in January 1990 at a depth of 50-100 mt. The starfish (500 g fresh) was extracted with water and then with acetone; from the aqueous extract the sulphated steroids and steroidal glycosides were recovered by passing it through a column of Amberlite, washing out salts with distilled water, and eluting the absorbed material with methanol. The acetone extracts were solvent partitioned between water and n-butanol. The combined methanol eluate and n-butanol soluble material, were separated by sequential application of gel permeation on Sephadex LH- 60, DCCC and HPLC, to give the sulphated steroids 1-3, in small amounts, ranging from 7.2 mg of 1 (major) to 3.4 mg of 3 (minor).

Two new sulphated polyhydroxylated steroid glucuronides. downeyoside A and B ( 1, 2 ), C-24 methyl epimers possessing an ethereal ring linking C-16 to C-22 of the steroid, were isolated from the starfish Henricia downeyae collected from the Gulf of Mexico. Their structures were determined by spectral analysis and the stereochemistry of the highly oxygenated steroid side chain was derived from NMR data combined with molecular dynamics calculation. Compounds 1 and 2 were tested against non-small-cell lung human carcinoma cells and found to be cytotoxic with IC50 of 60 μg/ml and 36 μg/ml, respectively.

Two novel polyoxygenated steroids, incrustasterol A ( 1 ) and B ( 2 ), have been isolated from the marine sponge Dysidea incrustans , collected in the Mediterranean sea along the coasts of Tunisia. The structures, which include a rare Δ 8(9) , 11-keto functionality along with other oxygenated functions on the rings A and B, were determined by interpretation of spectral data. These steroids were cytotoxic against human non-small-cell lung, renal and melanoma carcinoma cell lines.

Following the characterization of anchinopeptolide A[1], three new congeneric dimeric peptide alkaloids, named anchinopeptolides B [2], C[3], and D[4], have been isolated from the Mediterranean sponge Anchinoe tenacior. A fourth compound, cycloanchinopeptolide C[5], which is related to anchinopeptolide C[3] by a head-to-head intramolecular [2+2] cyclo-addition reaction, has also been isolated. The structures of these peptide alkaloids have been elucidated on the basis of spectral evidence. Anchinopeptolides bind to the somatostatin, human B2 bradykinin, and neuropeptide Y receptors.

A highly cytotoxic macrolide, superstolide A (1), has been isolated from the deep water marine sponge Neosiphonia superstes, collected off New Caledonia. The gross structure was determined by extensive 2D NMR experiments on the lactone 1 and on its opened-ring-derived methyl esters 2 and 3. The relative stereochemistries of the decaline moiety and of the C22-C26 fragment were determined by a combination of NMR data and acetonide analysis on 2. Absolute stereostructure of the decaline portion of 1 has been determined on the basis of GLC-modified Horeau's methodology applied to 4, whereas the results of the application of the modified Mosher's method to 1 and 3 allowed us to propose for the C22-C26 fragment the 22R, 23R, 24R, 25S, 26R configuration. We also propose the solution conformations of superstolide A (1) based on molecular dynamics and mechanics calculations using NMR-derived constraints.

Four new sulfated asterosaponins, designated as cosmasterosides A [1], B [2], C [4], and D [5], have been isolated from the Atlantic starfish Cosmasterias lurida along with large amounts of the pentaglycoside ophidianoside F [3] and the minor component forbeside H [6], previously isolated from Ophidiaster ophidianus and Asterias forbesi, respectively. Cosmasteroside A [1] contains the same oligosaccharide chain as ophidianoside F [3] and a (20S)-5 alpha-cholesta-9(11),24-diene-3 beta,6 alpha,20-triol-3 beta-sulfated aglycone. Cosmasterosides B [2], C [4], and D [5] are based on the known aglycone, thornasterol A, and differ in the number and type of monosaccharide components of the carbohydrate chain. Cosmasteroside B [2] contains a novel oligosaccharide chain that differs from that of ophidianoside F [3] by the replacement of the quinovose unit attached to C-6 of the steroidal aglycone by glucose. The tetraglycosides cosmasterosides C [4] and D [5] are structurally related to ophidianoside F [3] and cosmasteroside B [2], respectively, by the loss of a terminal fucose unit.

Anchinopeptolide A ( 1 ), a dimeric peptide alkaloid of a completely new type, has been isolated from the marine sponge Anchinoe tenacior collected in the Mediterranean sea along the coasts of Tunisia. The structure elucidation of 1 , which include in each half a C-terminal trans 4-hydroxystirylamino residue linked to L-alanine, which in turn is attached to an arginine derived 5-guanidino-2-hydroxy-pentanoyl residue, is described.

Following the characterization of callipeltin A (1), two new cytotoxic peptides, callipeltin B (2) and C (3), were isolated from the New Caledonian sponge Callipelta sp.. Callipeltin B (2) possess the same cyclic depsipeptidal structure as in callipeltin A (1) and differs from 1 by having the N-terminal 2,3-dimethylpyroglutamic acid unit instead of the tripeptide chain with the N-terminus blocked by an hydroxyacid. Callipeltin C (3) is simply the acyclic callipeltin A. The structures 2–3 have been determined by NMR experiments, FAB mass spectrometry, evaluation of the aminoacids obtained by acid hydrolysis and by comparison of the data with those of callipeltin A (1). Following the characterization of callipeltin A (1), two new peptides, callipeltin B (2) and C (3), were isolated form Callipelta sp.. Callipeltin B (2) possess the same cyclic depsipeptidal structure as in callipeltin A (1) and differs from 1 by having the N-terminal 2,3-dimethylpyroglutamic acid unit instead of the tripeptide chain with the N-terminus blocked by an hydroxyacid. Callipeltin C (3) is the acyclic callipeltin A. Callipeltins have been found to be cytotoxic against various human carcinoma cells.

A new nonsymmetric dimeric steroid, crellastatin A (1), was isolated from the Vanuatu Island marine sponge Crella sp. Structural assignment was accomplished through extensive 2D NMR spectroscopy. The stereochemistry of 1 was established from an analysis of ROESY experiments and from molecular mechanics and dynamics calculations. Crellastatin A (1), which possesses an unprecedented connection through the side chains, exhibits in vitro cytotoxic activity against NSCLC-N6 cells (IC50 of 1.5 μg/mL).

This paper reports a complete steroid glycoside and polyhydroxysteroid analysis of the starfish Solaster borealis, collected at Mutsu Bay, Japan. The glycosides include a new pentaglycoside steroid sulfate ("asterosaponin"), designated solasteroside A [1], two new sulfated 24-O-diglycosides, both with the common 5 alpha-cholesta-3 beta,6 alpha,8,15 alpha, 24-pentaol aglycone, borealosides A [2] and B [3], two new 24-O-(3-O-methyl)xylosides, borealosides C [4] and D [5], having the same aglycone with an additional hydroxy group at 4 beta-position in 5, and the known amurensoside B, previously isolated from Asterias amurensis. Among the polyhydroxysteroid constituents, four (7-10) are new, and five (11-15) have previously been isolated from starfishes.

Three steroid constituents have been isolated from the starfish Tremaster novaecaledoniae (Jangoux 1982) collected at a depth of 530 m off New Caledonia. Compounds 1 – 3 , designated as tremasterol A – C, are characterized by the presence of 3β-O-sulphated, 6α-O-phosphated and 16β-O-acetylated groupings on a steroidal skeleton. In compound 1 the monophosphate residue is further linked to 1′-glucose (1′-glucose tetracetate in 2 and 1′-glucose-6′-acetate in 3 ).

Along with two known cheilanthane sesterterpene lactones, 1 and 2, eight new related sesterterpenes (3–10) and two new nor-sesterterpenes (11 and 12) have been isolated from the New Caledonian marine sponge Petrosaspongia nigra Bergquist 1995 (new genus, new species). Their structures were determined from 1D and 2D NMR studies and mass spectral data. They exhibited cytoxicity against the NSCLC-N6 human bronchopulmunary non-small-cell-lung carcinoma cell lines.

Five new amino acid derivs. were isolated from the New Caledonian sponge Jaspis carteri, together with known bengamides A and B. The structures of the new compds. were detd. by interpretation of their spectral data and by comparison with spectral data of known bengamides. Bengamides G (I), and H, I, and J are simply the tridecanoate and pentadecanoate analogs of the original bengamides A and B, whereas bengamide K (II) is a caprolactam formamide deriv. of bengamide B.

A new nonsymmetric dimeric steroid, crellastatin A (1), was isolated from the Vanuatu Island marine sponge Crella sp. Structural assignment was accomplished through extensive 2D NMR spectroscopy. The stereochemistry of 1 was established from an analysis of ROESY experiments and from molecular mechanics and dynamics calculations. Crellastatin A (1), which possesses an unprecedented connection through the side chains, exhibits in vitro cytotoxic activity against NSCLC-N6 cells (IC(50) of 1.5mgr;g/mL).

A total of 19 steroids, of which 13 steroidal oligoglycosides (nine new and four known) and six polyhydroxylated steroids (four new and two known), has been isolated from the Antarctic starfish Acodontaster conspicuus. The mixture is dominated by glycosides composed of steroidal aglycons having the hydroxyl groups typically disposed on one side of the tetracyclic nucleus, i.e., 3 beta,4 beta,6 alpha,8,15 beta-, with some having a sulfate at C-6, and differing in the side chains and/or in the disaccharide moieties that are usually attached at C-26, with some at C-28 and C-29. Those compounds are accompanied by minute amounts of glycosides with a delta 8(14)-double bond in the steroid, which is a structural feature not previously found among polyhydroxysteroids derived from starfish. Small amounts of six related unglycosidated polyhydroxysteroids and three higher-molecular-weight asterosaponins complete the composition of the mixture. The structures of the new compounds were determined by interpretation of their spectral data and by comparison with spectral data of known compounds. Eighteen of these compounds were evaluated for their ability to inhibit growth in Antarctic marine bacteria isolated from either the water column or the surfaces of benthic marine invertebrates. Of these compounds, 50% were active against at least one Antarctic marine bacterium. This suggests that these compounds may play an important role in deterring microbial fouling.

Following the characterization of callipeltoside A (1), the first member of a novel class of marine glycoside macrolides, two more bioactive constituents, callipeltoside B (2) and C(3), were isolated from Callipelta sp. in very low amounts. The structures, assigned on the basis of spectral analysis, include the same 14-membered macrolide as in callipeltoside A (1) but differed in the saccharide moieties.

Thirteen new (1-13) and seven known (14-20) steroid glycosides were isolated from Henricia downeyae, collected from the offshore waters of the northern Gulf of Mexico. Ethanolic extracts of these starfish caused growth inhibition in bacteria and fungi, potent antifouling activity against barnacle and bryozoan larvae, and feeding deterrent activity against a marine fish. The known compounds are typical glycosides found in several species of the family Echinasteridae, i.e., Echinaster sp. and Henricia Laeviuscola. One of the new compounds belongs to this group, whereas the remaining 12 new compounds represent a novel series of steroid glycosides which have aglycons with structural similarities to the ''asterosaponins''. They possess a Delta(9(11)) 3 beta,6 alpha-dihydroxysteroidal aglycon with 23-oxo or 22,23-epoxy functionalities and often a 20-hydroxyl group in the side chain. The sulfate is located at C-6 and the saccharide moiety at C-3, in contrast with the asterosaponins which have the sulfate at C-3 and the oligosaccaride moiety at C-6. All the new compounds contain a glucuronic acid unit, which is uncommon among steroid glycosides from echinoderms. The structures of the new compounds, isolated in amounts ranging from 3.4 to 0.9 mg, were determined by interpretation of their spectral data and by comparison with spectral data of known compounds.

Following the characterization of callipeltin A (1), two new cytotoxic peptides, callipeltin B (2) and C (3), were isolated from the New Caledonian sponge Callipelta sp.. Callipeltin B (2) possess the same cyclic depsipeptidal structure as in callipeltin A (1) and differs from 1 by having the N-terminal 2,3-dimethylpyroglutamic acid unit instead of the tripeptide chain with the N-terminus blocked by an hydroxyacid. Callipeltin C (3) is simply the acyclic callipeltin A. The structures 2–3 have been determined by NMR experiments, FAB mass spectrometry, evaluation of the aminoacids obtained by acid hydrolysis and by comparison of the data with those of callipeltin A (1). Following the characterization of callipeltin A (1), two new peptides, callipeltin B (2) and C (3), were isolated form Callipelta sp.. Callipeltin B (2) possess the same cyclic depsipeptidal structure as in callipeltin A (1) and differs from 1 by having the N-terminal 2,3-dimethylpyroglutamic acid unit instead of the tripeptide chain with the N-terminus blocked by an hydroxyacid. Callipeltin C (3) is the acyclic callipeltin A. Callipeltins have been found to be cytotoxic against various human carcinoma cells.

Saponins have been considered for a long time typical metabolites of plant origin. It has been only in the last two decades that the world-wide investigation of marine organisms as sources of new bioactive metabolites disclosed the wide distribution of these molecules also among marine animals. Today saponins are recognized as the most common characteristic metabolites in two classes of the phylum Echinodermata (Holothuroidea and Asteroidea). Furthermore, several steroid and triterpenoid oligoglycosides have been isolated from different species of marine sponges, more rarely Anthozoans, and also from fishes of the genus Pardachirus, where they have been shown to act as shark repellents. This communication offers a general view of the distribution of steroid and triterpenoid oligoglycosides among marine organisms and focuses on a number of recent examples to discuss structural characteristics, biological activities, and methods of investigation.

Callipeltin A (1) is a cyclic depsidecapeptide from a shallow water sponge of the genus Callipelta (order Lithistida), collected in the waters off New Caledonia. The structure of callipeltin A (1), which possesses the N-terminus blocked with a β-hydroxy acid, and the C-terminus lactonized with a threonine residue, was determined by interpretation of spectral data, chemical degradation, and evaluation of the amino acids obtained by acid hydrolysis. Along with four common l-, one d-, and two N-methyl amino acids, it contains three new amino acid residues: β-methoxytyrosine (βOMeTyr), (2R,3R,4S)-4-amino-7-guanidino-2,3-dihydroxyheptanoic acid (AGDHE), and (3S,4R)-3,4-dimethyl-l-glutamine. Callipeltin A (1) has been found to protect cells infected by human immunodeficiency (HIV) virus.

The structure of two minor polyhydroxysteroids isolated from the deep water starfish Styracaster caroli were determined as (22E,24R,25R)-24-ethyl-5α-cholest-22-en-3β,5,6β,8,15α,25,26-heptol 26-sulf...

An investigation of the extracts from a starfish collected in the Antarctic Sea, Echinasteridae family, has led to the isolation of thirteen glycosides of polyhydroxysteroids (1–13), fourteen polyhydroxysteroids (14–27), which are the subject of this report, and seven asterosaponins (penta-and hexa-saccharides), described in a previous paper. Glycosides 1–13 are composed of the same 3β,4β,6α,8,15β,26-hexahydroxysteroidal aglycone with small variations in the side chains, and a carbohydrate portion made up of one or two monosaccharide units attached at C-26, except 11, which has a steroidal aglycone with a 24,28-dihydroxylated side chain and the monosaccharide unit attached at C-24. The structures of the polyhydroxysteroids (14–27) have the hydroxyl groups typically disposed on one side of the steroid nucleus, i.e. 3β,4β,6β (or α),8,15α (or β) and 16β and the majority of them possess a 26-hydroxyl function. A selection of fifteen compounds were tested against human non-small-cell lung carcinoma cells and found to be moderately cytotoxic.

Ten new [1-10] and three known [11-13] polyhydroxysteroids were isolated, along with four known asterosaponins [14-17], from the starfish Luidia clathrata, collected from the offshore waters of the northern Gulf of Mexico. The EtOH extracts of this starfish showed feeding-deterrent properties against marine fish, and inhibited the settlement of larvae of barnacles and bryozoans, as well as the growth of several bacteria. The structures of the new compounds were determined by interpretation of their nmr spectral data and by comparison with the spectral data of known compounds. The assignment of the configurations of the side-chain stereogenic centers of compounds 1 and 3-10 were based on the comparison of their nmr data with those of the stereoisomeric model compounds after derivatization with the chiral auxiliary MTPA reagent. Larval settlement assays conducted on ten isolated compounds revealed they are all potent inhibitors of settlement. Two of these isolated compounds inhibited the growth of several bacteria.

Two new 26-membered macrolides, reidispongiolide A (1) and B (2), have been isolated from the New Caledonian marine sponge Redispongia coerulea n.gen.n.sp. Levi and Levi and their structures elucidated. They are related to sphinxolides previously isolated from an unknown nudibranch and later from the sponge Neosiphonia superstes. 1 and 2 co-occurr with sphinxolide B (4) and D (3). These macrolides exhibited potent cytotoxicity against various human carcinoma cells.

Two new diastereomeric brominated tris-indole alkaloids occurring as enantiomeric pairs, (+/-)-gelliusines A [1] and B [2], have been isolated from a deep water New Caledonian sponge (Gellius or Orina sp.), whose crude extract exhibited cytotoxicity against KB cells. Their structures were elucidated by spectroscopic methods including one- and two-dimensional nmr spectroscopy. The major compound, (+/-) gelliusine A [1], which showed very weak cytotoxicity, proved to be active at the serotonin receptor.

Two novel sesquiterpenes,fulvanin 1 [1] and fulvanin 2[2], have been isolated from the Mediterranean sponge Reniera fulva. Compound 2 is a sesquiterpenoid linked to a hydroquinone. Also found in Reniera fulva are four known paniceins, a group of aromatic sesquiterpenoids linked to a quinol, isolated previously from Halichondria panicea. The total assignments of C-13-nmr spectra of paniceins have been made with the aid of 2D(HC)-H-1-C-13 correlation techniques, confirming their structures. The paniceins were tested in the in vitro disease-oriented primary antitumor screen at NCI, Bethesda. Paniceins C and B3 showed cytotoxicity against NCI-H522 non-small lung cancer cells and CCRF-CEM leukemia cells, while panicein A hydroquinone revealed more selective cytotoxicity against the latter ones.

A reinvestigation of the extracts from the starfish Distolasterias nipon, collected at Mutsu Bay, Japan, has led to the isolation of six glycosides of polyhydroxysteroids and six asterosaponins. Four steroidal glycosides have been identified as distolasterosides D1 [1] and D2 [2] (previously isolated from the same organism), and pycnopodioside C [5] and pisasteroside A [6], previously found in the related species Pycnopodia helianthoides and Pisaster ochraceus (family Asteridae), respectively. Two asterosaponins have been identified as the common versicoside A [7] and thornasteroside A [7a]. The two remaining glycosides of polyhydroxysteroids, named distolasterosides D4 [3] and D5 [4], and four asterosaponins designated nipoglycosides A [8], B [9], C [10], and D [11] are new compounds, and their structures have been elucidated mainly by interpretation of spectral data and comparison with known compounds.

Three novel polyhydroxysteroid constituents have been isolated from the starfish #Stracaster caroli$ collected at a depht of 2000 m off New Caledonia. These, designated carolisterols A - C (1 - 3), are characterized by a polyhydroxycholanic acid moiety, in which the 24-carboxylic acid function is found as an amide derivative ofD-cysteinolic acid. (Résumé d'auteur)

Three new macrolides 2–4 have been isolated with sphinxolide 1 from the marine sponge N. superstes collected off New Caledonia. The structures of the new compounds were determined by interpretation of NMR spectral data as well as by comparison of spectral data with those of 1. These compounds were highly cytotoxic against various human carcinoma cells.

A new carotenoid, designated as dehydroophioxanthin [2], has been isolated from the ophiuroid Ophiocomina nigra. The structure has been determined as (d+)′,(d+)′-di-dehydro-5,6,(d+)′,(d+)′-tetrahydro-β.β-carotene-3,4,(d+)′,(d+)′-tetraol 4,(d+)′ disulfate, which is related to the previous ophioxanthin from Opbioderma longicaudum. © 1991, American Chemical Society. All rights reserved.

1. 1. The composition of sterol mixture from the “living fossil” crinoid Gymnocrinus richeri collected off Noumea (New Caledonia) was investigated. 2. 2. The free 3β-OH sterol mixture was found to contain 14 components, Δ5 and ring saturated stanols, identified by GC-MS. 3. 3. Cholest-4-en-3-one, cholesta-1, 4-dien-3-one (this latter firstly isolated from a marine source), 5α-8α-epidioxy sterols, and 5α-ergosta-7,22-diene-3β,5,6β-triol were also present, their characterization being accomplished by EI-MS and 1H-NMR. The methanol extract also contained sterol sulphates, which were identified by GC-MS after solvolysis to remove the sulphate group.

Two 3 β - methoxy secosteroids, named jereisterol A and B were isolated from the pacific sponge Jereicopsis graphidiophora Levi & Levi. Their structures, which combine rare 3 β-methoxy and seco features, were determined as (24 R) 24-methyl-3β-methoxy-8α,9α-oxido-8,9-secocholesta-7,9(11)-diene (1) and (24R) 24-methyl-3β-methoxy-8,14-secocholesta-8,14-dione (2).

Extended spectroscopic analysis has led to the derivation of structure for a novel steroidal glycoside isolated from the starfish Astropecten indicus ; this compound, named indicoside A, contains a 5-0-methyl-β-galactofuranosyl moiety linked to C-28 of 24-methyl-5α-cholestane-3β,6α,7α,8,15β,24, 28-heptanol aglycone (1).

The total sterol content of the marine sponge Axinella verrucosa is a mixture of unique stanols containing a 3β-hydroxymethyl-A-nor-5α-cholestane nucleus with conventional C8, C9, and C10 side-chains.

Polar extracts of the ophiuroid Ophioderma longicaudun contain unusual sterol sulfates together with a mixture of common 3β-hydroxysterol sulfates. The more polar compound has been shown to be 5β-cholestane-3α, 4α,11β,12β,21-pentol 3,21-disulfate 1. A second group of unusual compounds are disulfated 3α,21-dihydroxysteroids. After solvolysis to remove the sulfate groups they have been identified as : (20R)-5α-cholestane-3α, 21-diol 4a, (20R)-cholest-5-ene-3α,21-diol 5a, (20R22E)-cholest-5,22-diene-3α,21-diol 6a and (20R)-24-methylcholest-5,24(28)-diene-3α,21-diol 7a. Analysis of the “non-sulfated” sterol fractions has shown the presence of common 3β-hydroxy sterols.

The aqueous extracts of the starfish Euretaster insignis contain two groups of sterol sulphates. The more polar compounds are sulphated 3β,21-dihydroxysteroids; after solvolysis to remove the sulphate groups they were identified as (20R)-24-methylenecholestane-3β,21-diol (3a)(major), (20R)-24-methylenecholest-5-ene-3β,21-diol (3b)(minor), (20R,22E)-24-methylcholest-22-ene-3β,21-diol (4a)(major), (20R)-cholestane-3β,21-diol (1a)(minor), (20R,22E)-cholest-22-ene-3β,21-diol (2a)(minor), and (20R)-cholest-5-ene-3β,21-diol (1b)(minor). The less polar compounds are sterol sulphates which are ‘normal’ constituents of starfishes. Analysis of the free sterols mixture has revealed that it contains a low level of cholest-7-en-3β-ol (3% of the total sterol mixtures) and C26, C27, C28, and C29 5α-steroidal alcohols. This finding, in contrast with previous results indicating the preponderance of Δ7-sterols in starfishes, could be related to the apparent absence of asterosaponins in this species.

Eight polyhydroxylated sterols, seven of them novel, have been isolated from the hepatopancreas of the scallop Patinopecten yessoensis. Compounds 1−7 possessed the same Δ 7 -3β,5α,6β-triol nucleus but differed in the side chains. One very minor component 8 had an additional hydroxyl group at C-9α. Their structures were deduced from spectral data and by comparison with synthetic model compounds

The structures of two minor polyhydroxysteroids isolated from the starfish Archaster typicus were determined as (22E,24R,25R)-24-methyl-5α-cholest-22-ene-3β,4β,5,6α,8,14,15α,25,26-nonaol (4) and (22E,24S)-24-methyl-5α-cholest-22-ene-3β,4β,5,6α,8,14,15α,25,28-nonaol (5).The stereochemistry at the C-24 and C-25 positions in compound (4) was determined by asymmetric synthesis of 2,3-dimethylpentane-1,2-diols as models and comparison of the spectral data of their 1(+)-MTPA esters with those of the 26-(+)-MTPA ester of the 22,23-dihydro derivative of the natural material. Similarly the stereochemistry at the C-24 position in compound (5) was proposed by comparison of the spectral data with those of a model compound.

Labelled acetate, phenylalanine and shikimic acid were fed to Bacillus acidocaldarius. A high proportion of the 14C incorporated from acetate and shikimate was recovered in methyl esters from the cell lipids, but such recovery of 14C from phenylalanine was low. Only the 14C from shikimate was selectively incorporated into 11-cyclohexylundecanoate and 13-cyclohexyltridecanoate. Degradation of these cyclohexyl-fatty acids showed that shikimate was incorporated as an intact C7 unit.

Three very minor polyhydroxylated sterols, 24ξ-methyl-26,27-bisnor-5α-cholest-22-ene-3β,4β,6β,8, 15α, 16β,25-heptol (5), 24ξ-methyl-27-nor-5α-cholestane-3β,-6β,8,15α,16β, 26-hexol (6) and 24ξ-methyl-27-nor-5α-cholestane-3β,4β,6β,8,15α, 16β,-26-heptol (7) have been isolated from the Mediterranean starfish Hacelia attenuata, along with 24-O-α-arabinosyl-5α-cholestane-3β,6α,8,15β,24ξ- pentol (8). Their structures have been proposed on comparative spectral data.

Two minor terpenoid components of the Spongia pitens have been identified as the 12-epimers-of scalarin (1) and deoxoscalarin (2), members of a new sesterterpene class recently discovered in sponges. With the aid of circular dichroism, and 1H and 13C n.m.r. spectroscopy, total stereochemistry has been assigned to the new compounds and their epimers.

With the aid of circular dichroism, n.m.r. shift reagents, and 13C n.m.r. spectroscopy the absolute stereochemistry has been assigned to avarol {2-[(1R)-1,2,3,4,4a,7,8,8aα-octahydro-1β,2β,4aβ,5-tetramethyl-1-naphthylmethyl]-hydroquinone}, obtained from the marine sponge Disidea avara. Avarol is the first naturally occurring sesquiter-penoid of the 9,4-friedodrimane type to be isolated.