Sea Hare Aplysia Dactylomela Research Articles

Marine natural products: halogenated acetylenic ethers from the sea hare Aplysia dactylomela

Marine natural products: halogenated acetylenic ethers from the sea hare Aplysia dactylomela

The inking behavior ofAplysia dactylomela(Gastropoda: Opisthobranchia): Evidence for distastefulness

1) Ink from the sea hare Aplysia dactylomela was examined to determine its possible role as a defensive mechanism by being distasteful to potential predators. 2) Feeding experiments were set up to determine the acceptance or rejection of various sections of Aplysia dactylomela and pieces of local baitfish (Mugil curema) containing Aplysia ink, to a population of laughing gulls (Larus atricilla). 3) Feeding experiments showed that Aplysia dactylomela ink was distasteful to laughing gulls. The gulls would reject pieces of baitfish which had been thoroughly coated with ink. The rejection rates by the gulls for baitfish injected with the ink was higher than the rejection rates towards certain parts of Aplysia, including those known to contain toxic material.

Studies on the nutrition and feeding preferences of Aplysia: Development of an artificial diet

An artificial diet made up principally of chemicals set in agar with a small amount of water extract of the green alga Ulva fasciata Delile has given good growth and spawn production in the sea hare Aplysia dactylomela Rang. The potential use of such a diet in the study of nutrition of sea hares and of other marine invertebrate herbivores is discussed and its possible rôle in identifying the characteristics of seaweeds which govern natural food choices in these animals is considered.

Artificial diets for sea hares

An artificial diet, made up principally of chemicals set in agar, has given good growth in the sea hare Aplysia dactylomela Rang (13 and 29% increases in live weight in two trials of 24- and 16-day periods, respectively, at 28.5 °C). Spawn production accounted for 65 and 29%, respectively, of these increases in weight. The role that such a diet may play in the study of nutrition and feeding preferences of sea hares and of other marine invertebrate herbivores is discussed.

Marine natural products: Deodactol, antineoplastic sesquiterpenoid from the sea hare aplysia dactylomela

Deodactol, a halogenated bisabolene-type sesquiterpene alcohol, has been isolated from the sea hare Aplysia dactylomela, and its structure and absolute configuration have been determined by X-ray diffraction. The compound crystallizes in the monoclinic system with the following crystal data: a=6.723(2), b = 11.838(1), c= 10.962(2) Å, β=99.41(2)°, V= 860.7; ϱx= 1.669 g cm −3 at −135±2°C; space group P2 1. The structure was solved by the heavy-atom method from 3-dimensional diffractometer data collected at −135±2°C using CuK α radiation. The final R factor for 1854 reflections is 0.029. The absolute configuration of the molecule was determined by the “R Method” of Hamilton. Deodactol has a strong intramolecular OHO hydrogen bond bridging its tetrahydropyranyl and cyclohexanol rings. The alcohol shows moderate cytotoxic activity. The absolute configuration of deodactol corresponds to that of several halogenated chamigrenes and supports the proposed biogenetic hypothesis linking halogenated bisabolenes and chamigrenes.

Marine natural products: sesquiterpene alcohols and ethers from the sea hare aplysia dactylomela

Marine natural products: sesquiterpene alcohols and ethers from the sea hare aplysia dactylomela

New Drug Metabolism Inhibitor of Marine Origin

Dactylyne, an acetylenic dibromochloro ether, was isolated from the sea hare Aplysia dactylomela and characterized pharmacologically. It had no direct effect on the cardiovascular, respiratory, and central nervous systems of mice, rats, and guinea pigs. However, a 25-mg/kg ip dose of dactylyne prolonged pentobarbital sleep time in mice by more than 10hr. This potentiation was subsequently determined to be due to the inhibition of pentobarbital metabolism by dactylyne since the elimination half-life of pentobarbital in the dactylyne-treated mice increased several folds. Dactylyne was nontoxic up to 200 mg/kg iv. The unique structure, high potency, and relatively nontoxic nature of dactylyne make it an interesting pharmacological substance of marine origin.

Marine natural products: dactylol, a new sesquiterpene alcohol from a sea hare

A new sesquiterpene alcohol, dactylol, having an uncommon bicyclo [6.3.0] undecane skeleton has been isolated from the sea hare Aplysia dactylomela. Chemical degradation and NMR studies using a shift reagent established the structure and relative stereochemistry. The absolute configuration was derived from ORD/CD data of a substituted cyclopentanone degradation product.

ChemInform Abstract: MARINE NATURAL PRODUCTS‐ ISODACTYLYNE, A HALOGENATED ACETYLENIC ETHER FROM THE SEA HARE APLYSIA DACTYLOMELA

Chemischer InformationsdienstVolume 8, Issue 6 Natural Products ChemInform Abstract: MARINE NATURAL PRODUCTS- ISODACTYLYNE, A HALOGENATED ACETYLENIC ETHER FROM THE SEA HARE APLYSIA DACTYLOMELA D. J. VANDERAH, D. J. VANDERAHSearch for more papers by this authorF. J. SCHMITZ, F. J. SCHMITZSearch for more papers by this author D. J. VANDERAH, D. J. VANDERAHSearch for more papers by this authorF. J. SCHMITZ, F. J. SCHMITZSearch for more papers by this author First published: February 8, 1977 https://doi.org/10.1002/chin.197706322Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume8, Issue6February 8, 1977 RelatedInformation

Marine natural products: isodactylyne, a halogenated acetylenic ether from the sea hare Aplysia dactylomela

These two halogenated ethers are members of a group of similar nonterpenoid C-15 ethers elaborated by red algae.3 Isodactylyne, a colorless oil, [ c u ] ~ ~ D -8.06, was isolated by chromatography from the hexane extracts of whole, dried sea hares. Purified, neat samples of isodactylyne deteriorated slowly a t room temperature and hence no combustion analysis was obtained. Mass spectral analysis established that this new halogenated ether has the same elemental composition (C1bH190Br2C1) as dactylyne; indeed, the fragmentation patterns of 1 and 2 were virtually identical. The presence in 2 of a terminal acetylene group conjugated with a double bond was indicated by ir (3300,2095 cm-I) and uv data (h,,, 224 nm, shoulder a t 233 nm; emax 15 500). The larger extinction coefficient in the uv spectrum of 2 relative to that of l1 suggested the trans geometry for the double bond of the enyne group.4 Comparison of the NMR spectra of isodactylyne and dactylyne, see Figure 1, revealed great similarity in structure between the two, and a t the same time confirmed that the enyne double bond of 2 is trans, as evidenced by the large coupling constant of the olefinic protons of the enyne group, 6 5.65 (broadened d, J = 16,142 Hz), 6.24 (doubled t, J = 16, 7 H z ) . ~ The triplet multiplicity in the 6 6.24 signal indicated coupling of this olefinic proton with an adjacent methylene group, thus confirming that the enyne side chain consisted of a t least five carbons. The olefinic proton signal centered a t 6 5.80 (t, J = 8 Hz) and the entire upfield portion of the spectrum of isodactylyne resembled that of dactylyne to such a degree that a direct correspondence in structure a t many points could be inferred. In fact, catalytic hydrogenation of 2 afforded a solid octahydromonodebromo product, mp 51.0-52.2 OC, M+ m l e 342,340, 338 (C15H2sBrCIO), which was identical with that obtained