Two new compounds, 3-amino-7,8-dihydroimidazo-[1,5-c]-pyrimidin-5(6H)-one (1) and ethyl 3-(2-amino-1H-imidazol-4-yl)propylcarbamate (2), along with the previously known 7,8-dihydroimidazo-[1,5-c]-pyrimidin-5(6H)-one (3), aeroplysinin-1 (4), dibromoverongiaquinol (5), bisoxazolidinone derivative (6), aerophobins-1 (7) and −2 (8), purealidins J (9) and L, have been isolated from Aplysina sp. from the South China Sea. The structures were elucidated on the basis of 1H, 13C NMR, MS and IR analyses. The histamine-derived alkaloids 1-3 may be unknown bioconversion products of purealidin J (9), aerophobin-2 (8) and aerophobin-1 (7), respectively, when 7-9 are cleaved at C-8–C-9 in reactions of activated chemical defense in Aplysina sponge.
FattorussoE, MinaleL, SodanoG. (1972) Aeroplysinin-1, an antibacterial bromo-compound from the sponge Verongia aerophoba. Journal of the Chemical Society, Perkin TransactionsI, 16–18.
5.
FulmorW, Van LearGE, MortonGO, MillsRD. (1970) Isolation and absolute configuration of the aeroplysinin I enantiomorphic pair from Ianthella ardis. Tetrahedron Letters, 4551–4552.
6.
YagiH, MatsunagaS, FusetaniN. (1993) Purpuramines A-I, new bromotyrosine-derived metabolites from the marine sponge Psammaplysilla purpurea. Tetrahedron, 49, 3749–3754.
7.
KobayashiJ, TsudaM, AgemiK, ShigemoriH, IshibashiM, SasakiT, MikamiY. (1991) Purealidins B and C, new bromotyrosine alkaloids from the Okinawan marine sponge Psammaplysilla purea. Tetrahedron, 47, 6617–6622.
8.
GunasekeraSP, CrossSS. (1992) Fistularin 3 and 11-ketofistularin 3. Feline leukemia virus active bromotyrosine metabolites from the marine sponge Aplysina archeri. Journal of Natural Products, 55, 509–512.
9.
IchibaT, ScheuerPJ, Kelly-BordesM. (1993) Three bromotyrosine derivatives, one terminating in an unprecedented diketocyclopentenylidene enamine. Journal of Organic Chemistry, 58, 4149–4150.
10.
KobayashiJ, HonmaK, SasakiT, TsudaM. (1995) Purealidins J-R, new bromotyrosine alkaloids from the Okinawan marine sponge Psammaplysilla purea. Chemical & Pharmaceutical Bulletin, 43, 403–407.
11.
TsukamotoS, KatoH, HirotaH, FusetaniN. (1996) Ceratinamine: an unprecedented antifouling cyanoformamide from the marine sponge Pseudoceratina purpurea. Journal of Organic Chemistry, 61, 2936–2937.
12.
CoppBR, IrelandCM, BarrowsLR. (1992) Psammaplysin C: a new cytotoxic dibromotyrosine-derived metabolite from the marine sponge Druinella (=Psammaplysilla) purpurea. Journal of Natural Products, 55, 822–823.
13.
KoulmanA, ProkschP, EbelR, BeekmanAC, van UdenW, KoningsAWT, PedersenJA, PrasN, WoerdenbagHJ. (1996) Cytotoxicity and mode of action of aeroplysinin-1 and a related dienone from the sponge Aplysina aerophoba. Journal of Natural Products, 59, 591–594.
14.
AcostaAL, RodriguezAD. (1992) 11-Oxoaerothionin: a cytotoxic antitumor bromotyrosine-derived alkaloid from the Caribbean marine sponge Aplysina lacunosa. Journal of Natural Products, 55, 1007–1012.
15.
TsudaM, ShigemoriH, IshibashiM, KobayashiJ. (1992) Purealidin D, a new pyridine alkaloid from the Okinawan marine sponge Psammaplysilla purea. Tetrahedron Letters, 33, 2597–2598.
16.
NakamuraH, WuH, KobayashiJ, NakamuraY, OhizumiY, HirataY. (1985) Purealin, a novel enzyme activator from the Okinawan marine sponge Psammaplysilla purea. Tetrahedron Letters, 26, 4517–4520.
17.
OkamotoY, OjikaM, KatoS, SakagamiY. (2000) Ianthesines A-D, four novel dibromotyrosine-derived metabolites from a marine sponge, Ianthella sp. Tetrahedron, 56, 5813–5818.
18.
GorshkovBA, GorshkovaIA, MakarievaTN, StonikVA. (1982) Inhibiting effect of cytotoxic bromine-containing compounds from sponges (Aplysinidae) on Na,K-ATPase activity. Toxicon, 20, 1052–1054.
19.
TsukamotoS, KatoH, HirotaH, FusetaniN. (1996) Ceratinamides A and B: new antifouling dibromotyrosine derivatives from the marine sponge Pseudoceratina purpurea. Tetrahedron, 52, 8181–8186.
20.
KlöppelA, PfannkuchenM, PutzA, ProkschP, BrümmerF. (2008) Ex situ cultivation of Aplysina aerophoba close to in situ conditions: ecological, biochemical and histological aspects. Marine Ecology, 29, 259–272.
21.
ThomsC, SchuppPJ. (2008) Activated chemical defense in marine sponges – a case study on Aplysinella rhax. Journal of Chemical Ecology, 34, 1242–1252.
22.
ThomsC, EbelR, ProkschP. (2006) Activated chemical defense in Aplysina sponges revisited. Journal of Chemical Ecology, 32, 97–123.
23.
MakarievaTN, StonikVA, AlcoladoP, ElyakovGB. (1981) Comparative study of the halogenated tyrosine derivatives from Demospongiae (Porifera). Comparative Biochemistry and Physiology, 68B, 481–484.
24.
SchlöglK, WoidichH. (1956) Über die cyclisierung von Histidinderivaten. Imidazo(1,5-c)tetrahydro-oxopyrimidin – einneues bicyclisches Ringsystem. Monatshefte fur Chemie, 87, 679–694.
25.
CiminielloP, CostantinoV, FattorussoE, MagnoS, MangoniA, PansiniM. (1994) Chemistry of verongida sponges, II. Constituents of the Caribbean sponge Aplysina fistularis forma fulva. Journal of Natural Products, 57, 705–712.
26.
SharmaGM, BurkholderPR. (1967) Studies on the antimicrobial substances of sponges II. Structure and synthesis of a bromine-containing antibacterial compound from a marine sponge. Tetrahedron Letters, 4147–4150.
27.
NorteM, RodriguezML, FernandezJJ, EgurenL, EstradaDM. (1988) Aplysinadiene and (R, R)-5-[3,5-dibromo-4-[(2-oxo-5-oxazolidinyl)]methoxyphenyl]-2-oxazolidinone, two novel metabolites from Aplysina aerophoba. Synthesis of aplysinadiene. Tetrahedron, 44, 4973–4980.
28.
CiminoG, De RosaS, De StefanoS, SelfR, SodanoG. (1983) The bromo-compounds of the true sponge Verongia aerophoba. Tetrahedron Letters, 24, 3029–3032.
29.
KobayashiJ, HonmaK, SasakiT, TsudaM. (1995) Purealidins J-R, new bromotyrosine alkaloids from the Okinawan marine sponge Psammaplysilla purea. Chemical & Pharmaceutical Bulletin, 43, 403–407.
30.
ThomsC, SchuppPJ. (2007) Chemical defense strategies in sponges: a review. In Porifera research – Biodiversity, innovation and sustainability. CustódioMR, Lôbo-HajduG, HajduE, MuricyG. (Eds). Série Livros 28Museu Nacional, Rio de Janeiro, Brazilia, 627–637.
31.
Ettinger-EpsteinP, MottiCA, De NysR, WrightAD, BattershillCN, TapiolasDM. (2007) Acetylated sesterterpenes from the Great Barrier Reef sponge Luffariella variabilis. Journal of Natural Products, 70, 648–651.
32.
GahanPB. (1981) Cell senescence and death in plants. In Cell death in biology and pathology. BowenID, LockshinRA. (Eds). Chapman & Hall, London, UK, 145–169.
33.
HällgrenJ, ÖquistG. (1990) Adaptations to low temperatures. In: Stress responses in plants: Adaptation and acclimation mechanisms. AlscherRG, CummingJR. (Eds). Wiley, New York, 265–293.
34.
TeeyapantR, ProkschP. (1993) Biotransformation of brominated compounds in the marine sponge Verongia aerophoba. Evidence for an induced chemical defense? Naturwissenschaften, 80, 369–370.
35.
GoldensteinG, FendertT, ProkschP, WinterfeldtE. (2000) Enantioselective preparation and enzymatic cleavage of spiroisoxazoline amides. Tetrahedron, 56, 4173–4185.
36.
EbelR, BrenzingerM, KunzeA, GrossHJ, ProkschP. (1997) Wound activation of protoxins in marine sponge Aplysina aerophoba. Journal of Chemical Ecology, 23, 1451–1462.
37.
CiminielloP, FattorussoE, MagnoS, PansiniM. (1994) Chemistry of verongida sponges, III. Constituents of a Caribbean Verongula sp. Journal of Natural Products, 57, 1564–1569;
38.
CiminielloP, FattorussoE, MagnoS, PansiniM. (1995) Chemistry of verongida sponges, IV. Comparison of the secondary metabolite composition of several specimens of Pseudoceratina crassa. Journal of Natural Products, 58, 689–696;
39.
CiminielloP, FattorussoE, MagnoS, PansiniM. (1996) Chemistry of verongida sponges VI. Comparison of the secondary metabolic composition of Aplysina insularis and Aplysina fulva. Biochemical Systematics and Ecology, 24, 105–113;
40.
CiminielloP, Dell'AversanoC, FattorussoE, MagnoS, PansiniM. (1999) Chemistry of verongida sponges. 9. Secondary metabolite composition of the Caribbean sponge Aplysina cauliformis. Journal of Natural Products, 62, 590–593.
