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Ramut Aviv 69978, TeI A&, Israd A s s m c r . S i x new diterpenoids, juncins A-F 1 2 -7 , possessing the known briarane skeleton have been isolated from a gorgonian collected from the Red Sea. The structures and relative stereochemistry of the juncins were determined by extensive 'H and 13C 1D and 2D nmr spectral analysis.Briarein A 11) isolated from the gorgonian Briarerrmashtinurn was the first reported example of these novel bicarbocyclic diterpenes (1-5). Diterpenes with the same skeleton as briarein A have been subsequently reported from octocorals belonging to the order Pennatulacea and also from Gorgonacea. Most recently a novel briarane diterpenoid was also isolated from a Mediterranean nudibranch and from its octocoral Our investigation of the gorgonian Juncdfa junceu Pallas (Gorgonaceae) has resulted in the isolation and identification of six new briarane diterpenes, 2-7. J . junceu was collected from sites in the entrances to the Gulf of Eilat and Gulf of Suez, Red Sea. The CH,Cl,-soluble extract of the freeze-dried horny coral was separated by repeated chromatographies on Si gel and RP-18 columns; a total of six compounds have been isolated and identified. These compounds, designated juncins A 121, B 131, C 141, D 151, E {6], and F [7), were isolated in yields of 0.00 14.008% (dry wt). The mass spectra of the juncins, together with their 'H-and 13C-nmr spectra (Tables 1 and 2) suggested the briarane skeleton. Characteristic in the mass spectra of 2-7 were the pairs of peaks differing by 2 amu with a relative intensity of 1:3, suggesting one chlorine atom in each compound.Juncin A [2] had the molecular formula C26H33C1010 (hreims, see Experimental), m/z 541/543 (3: 1, [MH]+, cims), and showed a uv absorption at A 220 nm (E 9000) and ir absorptions at v 3520, 1780, 1730, and 1720 cm-', typical for an alcohol, a ylactone, and one or more ester functionalities. Comparison of the 'H-nmr spectrum of 2 with that of

Six novel marine natural products, dysidamides B [3] and C [5], three highly oxygenated sterols 9, 11, and 13, and a 1,4-dideoxyhexose 15 were isolated from the Red Sea sponge Dysidea herbácea, along with the previously known 24-methylene-5ot-cholest-7--3ß,5,6ß-« 1 [7], furodysinin lactone, and -D-xy lopy ranose. Structures of all new compounds were determined from spectroscopic data, especially extensive ID and 2D nmr experiments.Many interesting metabolites have been isolated from Dysidea species (1-7). Recently we have reported the isolation of a chlorinated nitrogenous metabolite, dysidamide [1], from a Dysidea sp. collected near Massawa, Ethiopia (8), a sponge which has now been fully identified as Dysidea herbácea Keller (family Dysideidae, order Dictyoceratida). An unusually diverse array of metabolites has been isolated from various specimens of D. herbácea (1,4). Herewith we wish to report several minor metabolites from the same sponge: two new dysidamides, B [31 and C {5}, four polyoxygenated sterols 7, 9, 11, and 13, and a dideoxyhexose 15, which were isolated with Dxylose and furodysinin lactone (7).The EtOH extract of the sponge was separated into four fractions by chromotography on a Sephadex LH-20 column prepared and eluted with petroleum ether-CH2Cl2-MeOH (2:1:1); the fractions contained (a) glycerides and non-polar sterols, (b) dysidamides, (c) polar sterols, and (d) monosaccharides. The three latter fractions were further purified by repeated chromatography on Sephadex LH-20 and RP-18 columns and also, in some cases, on Si gel after acetylation with Ac2OZpyridine (it was verified that there are no natural acetates of the new compounds). Together with compound 1, which was the major metabolite (2% dry wt of the sponge), we have now isolated small

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A new hydroxy phenylheptadienoic acid [1] has been isolated from the ascidian Didemnum granulatum collected from the Gulf of Eilat in the Red Sea.

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