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A new chloro-trinoreremophilane sesquiterpene 1, three new chlorinated eremophilane sesquiterpenes 2–4, together with a known compound, eremofortine C (5), were isolated from an Antarctic deep-sea derived fungus, Penicillium sp. PR19N-1. Structures were established using IR, HRMS, 1D and 2D NMR techniques. In addition, the plausible metabolic network of these isolated products is proposed. Compound 1 showed moderate cytotoxic activity against HL-60 and A549 cancer cell lines.

dione (7), were isolated from the marine-derived fungus Aspergillus flavus. Their structures were determined by analysis of spectroscopic data. The cytotoxicities of compounds 1 and 2 were studied using HL-60, Key words: Aspergillus flavus, cyclopiazonic acid, cytotoxic activity.α-Cyclopiazonic acid (α-CPA) was a mycotoxic metabolite first isolated from Penicillium cyclopium Westling [1]. Since then, several other Penicillium and Aspergillus strains, including P. camembert and A. flavus and A. tamarii, were also found to produce α-CPA [2-4]. It has a range of biological activities, most notably Ca 2+ -ATPase inhibition, and can be used as a tool for the elucidation of intracellular Ca 2+ influx [5][6][7]. In the course of our search for new anticancer compounds from marine microorganisms, iso-α-cyclopiazonic acid (iso-α-CPA) (1) and α-CPA (2), together with three mycotoxins: aflatoxin B 1 (AFB 1 ) (3), aflatoxin Q 1 (AFQ 1 ) (4), and O-methylsterigmatocystin (OMST) (5); two diketopiperazine alkaloids: ditryptophenaline (6) and 3-[(1H-indol-3-yl)methyl]-6-benzylpiperazine-2,5-dione (7), were isolated from the A. flavus strain (c-f-3) isolated from marine algae, collected in Putian Pinghai, China. Compound 1 was first synthesized by Holzapfel in 1968 and isolated as a natural product for the first time. In this paper, we report the isolation and structure elucidation of 1, and the cytotoxic activities and structure-activity relationships of 1 and 2.Compound 1 shows a quasi-molecular ion peak at m/z 337 [M+H] + in the positive ESI-MS, and together with the 1 H and 13 C NMR spectra, supported the molecular formula of 1 (C 20 H 20 N 2 O 3 ) as 2. 1 H and 13 C NMR data (Table 1) disclosed the existence of eight sp 2 quaternary carbons, four sp 2 methines, three sp 3 methines, one sp 3 quaternary carbon, one sp 3 methylene, and three methyl groups. The 13 C NMR spectrum of 1 showed the characteristic carbon signals assignable to amide (δ C 173.2), ketone (δ C 195.0), and enol (δ C 183.1, 107.1), indicating that 1 possessed a tetramic acid ring. Four lower-field proton signals at δ H 6.89 (s), 7.11 (d, J = 8.0 Hz), 7.02 (dd, J = 8.0, 7.1 Hz), and 6.78 (d, J = 7.1 Hz), together with eight olefinic carbons (δ C 123.5 d, 109.1 s, 129.9 s, 116.3 d, 120.8 d, 108.7 d, 134.6 s, 128.4 s), suggested the presence of a disubstituted indole ring. Comparison of the NMR spectral data (Table 1) of 1 with those of 2 showed that 1 has the same planar structure as 2. The 1 H NMR data of 1 differed from those of 2 only in the chemical shifts of H-4 (δ H 3.78), H-5 (δ H 4.64), and H-11 (δ H 3.27), which shifted 0.10, 0.53, and 0.67 ppm more downfield than 2, respectively; and H-21 (δ H 0.85) and H-22 (δ H 1.48), which shifted 0.75 and 0.2 ppm more upfield than 2; further comparison of their CD data suggested that the only difference was the stereochemistry of C-5, viz 2 has S configuration, while 1 has R. So 1 was identified as iso-α-cyclopiazonic acid, in agreement with the reported NMR and CD data in the literature [1,8].

Chemical investigation of an Antarctic deepsea derived fungus Penicillium sp. PR19 N-1 yielded five new eremophilane-type sesquiterpenes 1–5 and a new rare lactam-type eremophilane 6, together with three known compounds 7–9. The structures of these diverse sesquiterpenes were determined by extensive NMR and mass spectroscopic analyses. Compounds 1, 2, 4–6, 8 and 9 were evaluated for their cytotoxities against HL-60 and A-549 human cancer cell lines, and 5 was the most active one with IC50 value of 5.2 lM against the A-549 cells.

Two new compounds, 4-(hydroxymethyl)-5-hydroxy-2H-pyran-2-one (1) and (5-hydroxy-2-oxo-2H-pyran-4-yl) methyl acetate (2), have been isolated from a marine-derived fungus Aspergillus flavus. Their structures were determined by spectroscopic data. Compound 1 induced the production of cAMP on GPR12 transfected CHO and HEK293 cells in a dose-dependent manner, which indicated 1 might be a possible ligand for GPR12.Keywords marine-derived fungus, Aspergillus flavus, 5-hydroxy-2-pyrone, cAMP, GPR12 Introduction 2-Pyrone is a six-membered cyclic unsaturated ester, which is highly abundant in bacteria, microbial, plant, insect and animal systems and takes part in many different types of biological processes such as defence against other organisms, as key biosynthetic intermediates, and as metabolites [1]. A wide range of bioactivities such as plant growth-regulating [2,3], antitumour [4,5], antimicrobial and antifungal activities [6,7] have demonstrated the medicinal importance of 2-pyrones. In our search for new bioactive compounds from the marine-derived fungus Aspergillus flavus c-f-3 separated from a marine algae sample collected in Putian Pinghai, China, two new 5-hydroxy-2-pyrone derivatives (1, 2) were isolated. The biological activities of 1 and 2 were tested using cAMP assay in GPR12 transfected CHO and HEK293 cells. In this paper we described the isolation and structure elucidation of 1 and 2 (Fig. 1) as well as their bioactivities. Materials and Methods MicroorganismThe Aspergillus flavus c-f-3 was separated from a marine algae Enteromorpha tubulosa, collected at Putian Pinghai, China, in August, 2005, using dilution-plate method [8] on PDA medium [9]. It was identified according to its morphological characteristic by Prof. Hong Kui (the Chinese Academy of Tropical Agricultural Sciences, Hainan, China). Working stocks were prepared on Potato Dextrose agar slants stored at 4°C. Two New 5-Hydroxy-2-pyrone Derivatives Isolated from a Marine-derived Fungus

Three new furan and pyran derivatives named aspericins A-C (1-3), as well as a known asperic acid (4), have been isolated from the marine-derived fungus Rhizopus sp. 2-PDA-61. The complete (1)H and (13)C NMR assignments for the new compounds were carried out using (1)H, (13)C, DEPT, COSY, HMQC, HMBC, and NOESY NMR experiments. Compounds 1-3 were evaluated for their cytotoxic activities on P388, A549, HL-60, and BEL-7420 cell lines by the MTT and SRB methods.

Two New 5-Hydroxy-2-pyrone Derivatives (I) Isolated from a Marine-Derived Fungus Aspergillus flavus. -[structure and bioactivities]. -(LIN, A.; LU, X.; FANG, Y.; ZHU, T.; GU, Q.; ZHU