Siladenoserinols M–P,sulfonated serinol derivatives from a tunicate

Four new sulfonated serinol derivatives, siladenoserinols M–P (1–4), were isolated from a tunicate of the family Didemnidae collected in Indonesia. Their chemical structures were elucidated by the interpretation of NMR and mass spectroscopic data. Two of them (2 and 4) were revealed to be disulfonate serinol derivatives, and the others were monosulfonates. Siladenoserinols A (5) and B (6), which we previously isolated from the same tunicate, inhibited the p53–Hdm2 interaction with an IC₅₀ value of 2.0?μM. However, 1–4 did not inhibit the activity. The result suggested that the acetyl group in the bicyclic ketal unit and/or the glycerophospholipid moiety in 5 and 6 were responsible for the inhibition of the p53–Hdm2 interaction.     

The structures of three new shishididemniols from a tunicate of the family Didemnidae

Three new serinolipid derivatives, shishididemniols C (1), D (2), and E (3), were isolated as antibacterial constituents of a tunicate of the family Didemnidae. Their planar structures were elucidated by interpretation of NMR and MS data, whereas the absolute stereochemistry was determined by chemical conversions. Shishididemniols C (3), D (4), and E (5) exhibited antibacterial activity against the fish pathogenic bacterium Vibrio anguillarum.     

皱瘤海鞘的化学成分研究

从中国广东惠州大亚湾海域采集的皱瘤海鞘的甲醇-氯仿提取物中分离出混合甾醇和神经酰胺两类化合物,混合甾醇经波谱分析和GC/MS联机分析,发现基主要由9种甾醇组成,含量约为甲醇-氯仿提取物的20%。通过波谱分析（如IR,^1HNMR,^13CNMR（DEPT）、^1H-^1H COSY、RCT、FABMS）和GC/MS分析证明神经酰胺结构是由4个同系物组成,含量为提取物的0.1%。同时也初步探讨了共生的皱瘤海鞘与冠瘤海鞘化学成分差异的原因。     

Lissoclibadins 1-3, three new polysulfur alkaloids, from the ascidian Lissoclinum cf. badium

Three new polysulfur alkaloids, lissoclibadins 1 (1)-3 (3), were isolated from the ascidian Lissoclinum sp. (cf. L. badium Monniot, F. and Monniot, C., 1996). The structures of 1-3 were assigned on the basis of their spectral data, and the computational modeling study was utilized for 1. Compound 1 had a trimeric structure of three identical aromatic anime moieties connected through two sulfide and a disulfide bonds. Compounds 2 and 3 were dimeric structures of the same unit as that of 1 connected through a sulfide and disulfide bonds (2) and two sulfide bonds (3). Compounds 1 and 2 inhibited the growth of the marine bacterium Ruegeria atlantica (15.2 mm at 20 μg/disk and 12.2 mm at 5 μg/disk, respectively) and 2 showed antifungal activity to Mucor hiemalis (13.8 mm at 50 μg/disk). Compounds 1-3 were cytotoxic against HL-60 (IC₅₀=0.37, 0.21, and 5.5 μM, respectively).     

冠瘤海鞘的化学成分

从中国惠州大亚湾海域采集的冠瘤海鞘的甲醇－氯仿提取物中分离出混合甾醇和神经酰胺两类化合物,混合甾醇经波谱分析和GC／MS联机分析,发现其主要由十种甾醇组成,含量为甲醇－氯仿提取物的12％。神经酰胺为十八碳酰基鞘氨醇,其结构通过波谱鉴定,含量为提取物的0.3%,这是有关冠瘤海鞘化学成分研究的首次报道。     

Antifungal effects of secondary metabolites isolated from marine organisms collected from the Tunisian coast

Phallusides 1,2,3 (1), Fasciculatin (2), Acanthelline (3), Axisonitrile (4), Oroïdin (5) and the Novel bromopyrolimidazolic compound Axinellizine (6) were evaluated for their antifungal effects against several phytopatogenic fungi and were found to possess considerable activities. Insecticidal effect of only Acanthellin (3) against the major pest of stored products Tribolium confusum Duv has been carried out using direct contact application method showing a significant inhibitory effect of the test material on the T. confusum Duv larvae growth. Forty-five percent mortality of the adults was achieved 8 days after treatment.     

Lissoclibadins 8-14, polysulfur dopamine-derived alkaloids from the colonial ascidian Lissoclinum cf. badium

Seven new polysulfur alkaloids, lissoclibadins 8 (1)-14 (7), were isolated from an ascidian, Lissoclinum cf. badium, collected in Indonesia. The structures were assigned on the basis of their spectroscopic data and computational modeling study. Lissoclibadin 8 (1) had four identical dopamine-derived units, and this is the first instance of a tetramer. Lissoclibadin 9 (2) was the second example of trimers next to lissoclibadin 1 (8). Lissoclibadins 10 (3)-12 (5) were symmetric dimers, and 13 (6) had a dopamine and ethyl units connected by sulfide and disulfide bonds. Lissoclibadin 14 (7) was a varacin-type monomer. These compounds inhibited the colony formation of Chinese hamster V79 cells and cell proliferation of murine leukemia L1210 cells.     

Synthesis of the C3-14 fragment of palmerolide A using a chiral pool based strategy

Palmerolide A, a potent and selective inhibitor of melanoma cell growth, is a macrocylic polyketide isolated from the Antarctic tunicate Synoicum adareanum. Palmerolide A targets transmembrane proton pumps, the vacuolar-ATPases, and induces autophagy, but in a manner independent of HIF-1α activation. Herein we report a synthesis of the C3-14 fragment of palmerolide A using readily available polyols as chiral building blocks for entry into structure/activity studies of the macrocycle.     

Lissoclibadin 1, a novel trimeric sulfur-bridged dopamine derivative, from the tropical ascidian Lissoclinum cf. badium

A novel tribenzotetrathiepin alkaloid, named lissoclibadin 1 (1), has been isolated from the ascidian Lissoclinum sp. (cf. L. badium Monniot and Monniot, 1996). The gross structure was assigned on the basis of the spectral data, and one of two possible isomers was selected by the computational modeling study. Lissoclibadin 1 inhibited the growth of the marine bacterium Ruegeria atlantica (15.2 mm at 20 μg/disk).