Key words sponge; Axinyssa sp.; bisabolene-type; cytotoxicity Studies in the chemistry of marine natural products, the marine sponges have emerged as one of the most prolific sources for discovery of novel secondary metabolites.1) Previous chemical investigations on sponges of the genus Axinyssa (order Halichondrida, family Halichondriidae) have led to the isolation and identification of various sesquiterpenes containing unusual nitrogenous functional groups as an isocyano, isothiocyanate, thiocyanate, bisabolene and formamide group.2-15) Some of these N-containing compounds have been found to possess several kinds of biological activities, such as antithelmintic, 2) antimicrobial, 4) antimalarial, 6) antifouling, 11) cytotoxic activities 12) and lethality for brine shrimp. 10) Our investigation of the chemical constituents of a sponge Axinyssa sp. yielded two new nitrogenous bisabolene-type sesquiterpenes, axinysalines A (1) and B (2), along with three known sesquiterpenes. The structures of 1 and 2 were established by detailed spectroscopic analysis and comparison of their NMR data with those of known analogues. The known sesquiterpenes were readily identified as 3-isocyanotheonellin (3), 16) 3-isocyano-7,8-epoxy-α-bisabolane (4) 7) and 3-formamidotheonellin (5), 17) by comparison of their spectral data with those reported in the literature. The cytotoxicity of metabolites 1-5 against the six cancer cell lines, human erythromyeloblastoid leukemia (K562), human T lymphoblast, acute lymphoblastic leukemia (Molt 4), human colon adenocarcinoma (HCT-116 and DLD-1), and human breast carcinoma (MDA-MB-231 and T47D) was studied.Compound 1, named axinysaline A, was isolated as an optically active, colorless oil. The molecular formula was determined to be C 21 H 35 NO 3 by high resolution-electrospray ionization (HR-ESI)-MS (m/z 372.2515, C 21 H 35 NO 3 Na) and NMR data, which corresponded to five degrees of unsaturation. The IR spectrum of 1 showed absorption bands at 3375, 1679 and 1746 cm −1 , suggesting the presence of an amide CO group and an ester CO group, which were supported by 13 C-NMR chemical shifts at δ 171.9 and 169.2 ppm, respectively. The 13 C-NMR and distortionless enhancement by polarization transfer (DEPT) spectral data of 1 showed the presence of 21 carbons (Table 1): seven methyls, four sp 3 methylenes, two sp 3 methines, three sp 2 methines, and two sp 3 quaternary carbons. The remaining three signals appearing in the lower field region of the spectrum are due to the quaternary carbons of one olefinic carbon (δ 140.2), one amide carbonyl and one ester carbonyl. From the 1 H-NMR spectrum of 1, the resonances of three olefinic protons (δ H 6.22, dd, J=14.5, 11.0 Hz; 5.81, d, J=11.0 Hz; 5.59 dd, J=15.5,7.0 Hz) were observed. Moreover, analysis of the 1

One new 5α,8α-epidioxysterol, 3-acetylaxinysterol (1), along with one known sterol, axinysterol (2), were isolated from a Formosan sponge, Axinyssa sp.. The structures of the compounds were determined by spectroscopic methods and the absolute configuration of 2 was further confirmed by single-crystal X-ray diffraction analysis for the first time. Compound 2 exhibited significant cytotoxicity against K562 and Molt 4 cancer cell lines.

One new norsesterterpene peroxide, rhopaloic acid H (1), along with two known related metabolites 2 and 3, were isolated from a marine sponge Hippospongia sp. The structures of compounds were elucidated by means of IR, MS, and NMR techniques and comparison of the NMR data with those of known analogues. Evaluation of the cytotoxicities revealed that compound 2 exhibited significant cytotoxicity against DLD-1, Molt 4, T47D and K-562 cell lines, with IC 50 values of 3.18, 0.69, 2.22 and 1.06 μg/mL, respectively. Moreover, compound 3 also showed significant K562 inhibitory activity, with IC 50 value of 3.65 μg/mL.