New Bromotyrosine Derivatives from an Association of Two Sponges, Jaspis wondoensis and Poecillastra wondoensis Yujin Park, † Yonghong Liu, † Jongki Hong, ‡ Chong-O. Lee, § Heeyeong Cho, § Dong-Kyoo Kim, ⊥ Kwang Sik Im, † and Jee H. Jung* ,† College of Pharmacy, Pusan National University, Busan 609-735, Korea, Korea Basic Science Institute, Seoul, Korea, Pharmaceutical Screening Center, Korea Research Institute of Chemical Technology, Daejon, Korea, and Department of Chemistry, Inje University, Gimhae, Korea Received April 11, 2003 Three new bromotyrosine derivatives (4-6) were isolated from an association of two sponges, Jaspis wondoensis and Poecillastra wondoensis, along with the previously described (E,E)-psammaplin A (1), (E,Z)-psammaplin A (2), psammaplin D (3), bisaprasin (7), and (3-bromo-4-hydroxyphenyl)acetonitrile (8). The structures of the new compounds were established on the basis of NMR and MS spectroscopic analysis. The compounds 1, 3, and 5-7 displayed significant cytotoxicity against human lung (A549), ovarian (SK-OV-3), skin (SK-MEL-2), CNS (XF498), and colon (HCT15) cancer cell lines. Compounds 3-7 were further evaluated for antibacterial activity against methicillin- or ofloxacin-resistant Staphy- lococcus strains. Compound 4 exhibited more potent antibacterial activity than meropenem against several strains. Bromotyrosine derivatives are considered as chemotaxo- nomic markers of sponges of the order Verongida. Although bromotyrosines were mostly encountered in verongid sponges, they have recently been isolated from nonverongid sponges. 2,12,13 Bromotyrosine derivatives range from simple bromotyrosine monomers represented by aeroplysinin-1 1 to more complex bastadins, 10,11 some of which are macro- cycles comprised of several bromotyrosine units. Among these metabolites, psammaplins and related compounds 2-9 comprise a small group of metabolites that appear to be biosynthesized by linear connection of bromotyrosines and modified cysteines. Various biological activities of these compounds were reported, and especially for psammaplin A, bioactivities such as antimicrobial activity, 3,7 cytoxicity against the leukemia cell-line P388, 2,8 and inhibition of DNA topoisomerase ΙΙ 9 were reported. We previously isolated pectenotoxin ΙΙ and (E,E)-psam- maplin A (1) from an association of two nonverongid sponges, Jaspis wondoensis and Poecillastra wondoensis. 2 Pectenotoxin ΙΙ and (E,E)-psammaplin A exhibited unique bioactivities such as cytotoxicity against human tumor cell lines 2 and antibacterial activity against methicillin- resistant Staphylococcus aureus, 3 respectively. In our continuing search for novel bioactive bromotyrosine deriva- tives from the two-sponge association, new psammaplin derivatives (4-6) were isolated. Compound 4 and (E,E)- bromopsammaplin A (5) are the structural analogues of psammaplin A, containing an additional sulfur or bromine in their structures. Bispsammaplin A (6) is an ether-linked dimeric form of (E,E)-psammaplin A (1), while bisaprasin (7) is a carbon-carbon coupled dimeric form of (E,E)- psammaplin A. The gross structures of the compounds were elucidated on the basis of NMR and MS analyses. Herein we describe the isolation, structure elucidation, and bio- logical evaluation of the new compounds. The MeOH extracts of the frozen sponges were evapo- rated in vacuo and partitioned between H 2 O and CH 2 Cl 2 . Bromotyrosine derivatives were found to be distributed in both the H 2 O and CH 2 Cl 2 partitions, as evidenced by the 1 H NMR spectrum of each partition. Selected fractions from both partitions were successively purified by reversed- phase flash column chromatography, MPLC, and HPLC to afford eight bromotyrosine derivatives (1-8). Five known compounds, namely, two isomeric psammaplin A (1, 2), 2-9 psammaplin D (3), 4 bisaprasin (7), 7 and (3-bromo-4-hy- droxyphenyl)acetonitrile (8), 4-6 were identified by compari- son of their spectroscopic data with those reported in the literature. Compound 4 was obtained as a white amorphous solid. The presence of 3-bromo-4-hydroxyphenyl (δ 7.35, 6.74, 7.05; H-2, 5, 6) and isolated benzylic methylene (δ 3.79; H-7) moieties was deduced from comparison of the 13 C and 1 H NMR data with those of 1 (Table 1). The NMR data of 4 were almost identical to those of (E,E)-psammaplin A (1) with the only exception that the signals corresponding to the protons and carbons of heteroatom-substituted meth- ylenes were shifted (δ 3.60/2.99, 39.0/37.8; H-11/12, C-11/ 12) from those observed for 1 (δ 3.51/2.80, 39.5/38.5; H-11/ 12, C-11/12). The FABMS spectrum of 4 showed a cluster of isotopic [M + H] + ion peaks at m/z 695/697/699 in approximate ratio of 1:2:1, respectively, indicating the presence of two bromine atoms in the molecule. The obser- vation of only 11 carbon signals in the 13 C NMR spectrum revealed that it has a symmetric structure. The [M + H] + ion cluster has shifted 32 amu from those of 1 and 2, indicating the presence of an additional sulfur or two oxygens, which could be placed only at the central unit of the structure to explain the symmetry of 4. Also ESIMS of 4 showed fragment ions at m/z 363/365 (C 11 H 12 N 2 O 3 S 2 Br) and 466/468 (C 14 H 17 N 3 O 4 S 3 Br), a fragmentation pattern that paralleled that of (E,E)-psammaplin A (1) (Figure 1). The fragment ions at m/z 363/365 were observed as base peaks in the ESIMS/MS experiment. The exact mass of the pseudomolecular ions could not be measured by FABMS due to weak ion currents. By a more sensitive but less accurate MALDI-TOFMS, the [M + Na] + ion was detected at m/z 718.9037, which is within tolerable range (calcd for C 22 H 24 N 4 O 6 S 3 79 Br 81 BrNa, 718.9102). Thus, the most fea- * To whom correspondence should be addressed. Tel: 82-51-510-2803. Fax: 82-51-510-2803. E-mail: jhjung@pusan.ac.kr. † Pusan National University. ‡ Korea Basic Science Institute. § Korea Research Institute of Chemical Technology. ⊥ Inje University. 1495 J. Nat. Prod. 2003, 66, 1495-1498 10.1021/np030162j CCC: $25.00 © 2003 American Chemical Society and American Society of Pharmacognosy Published on Web 10/15/2003