The Berkeleyacetals, Three Meroterpenes from a Deep Water Acid Mine Waste Penicillium

Abstract

Berkeley Pit Lake is a 1500 ft. deep abandoned open-pit copper mine filled with over 1140 billion liters of acidic, metal-sulfate contaminated water. This harsh environment is proving to be a source of unusual microorganisms that produce novel bioactive compounds. We recently reported the structures of berkeleydione (1) and berkeleytrione, two novel hybrid polyketide-terpenoid metabolites isolated from a deep water Penicillium sp. growing in Berkeley Pit lake. In this paper we report the structures of three new compounds, berkeleyacetals A-C (3-5) isolated from extracts of this fungus. The structures of these compounds were deduced by comparison of mass spectral and NMR data to that of berkeleydione 1.The Berkeley Pit Lake System is part of the largest EPA Superfund site in North America. Berkeley Pit Lake contains roughly 1140 billion liters of acidic (pH 2.5), metal-sulfate rich water that sits poised at the head of the Columbia River ecosystem. 1 We are studying the secondary metabolism of the culturable microbes isolated from Pit water and sediment samples. Several interesting compounds have been isolated from these microbes based on their activities in different bioassay guided fractionation schemes. [2][3][4][5][6] One of the first microbes to be studied from this environment was isolated from a depth of 885 feet and was subsequently identified as Penicillium rubrum Stoll based on rRNA sequencing alignment data (300 base pairs). 3 The fungus was grown in acidified potato dextrose broth (pH 2.7, still) for 21 days. At harvest time the fungus was killed by the addition of MeOH, the mycelia removed by gravity filtration and the filtrate extracted with CHCl 3 . The CHCl 3 extract inhibited both MMP-3 and caspase-1 in assay systems so it was fractionated by LH-20 column chromatography followed by HPLC to yield berkeleydione (1) and berkeleytrione (2). 3 The 1 H NMR spectra from all of the column fractions were examined for evidence of related analogs. Promising candidates were purified and tested for activity. The three new berkeleyacetals 3-5 were isolated based on this "NMR guided" fractionation as well as their activity in both enzyme bioassays. We report here the isolation and characterization of berkeleyacetals A-C, (3-5). The structures were established based upon extensive spectroscopic data and a single crystal X-ray structure for 1.We are exploring the possibility of isolating compounds with anticancer potential using in vitro signal transduction bioassay systems. Two enzyme inhibition schemes have shown promising correlation to the National Cancer Institutes Developmental Therapeutics Program human cancer cell line assay. To date, compounds isolated in our lab based on these assays have shown activity against non-small cell lung cancer 3 and ovarian cancer 4 . Matrix metalloproteinases (MMP) hydrolyze the extracellular matrix of connective tissues and basement membranes. 7, 8 MMP-3 is up-regulated in many tumors 9, 10 and can induce *To whom correspondence should be addressed. Tel: (406) Casp...

3,5‐Dimethylorsellinic Acid Derived Meroterpenoids from Eupenicillium sp. 6A‐9, a Fungus Isolated from the Marine Sponge Plakortis simplex

“…Eupeniacetal A (1) was evidenced to have a molecular formula of C 26 H 32 O 8 [the same as berkeleyacetal A (9) [11] ] with 11 degrees of unsaturation, based on its [ C NMR spectroscopic data of 1 with those of 9 revealed that they have exactly the same number of quaternary carbon atoms, methine, methylene, and methyl carbon atoms (Table 1 and Table S10 in the Supporting Information). This similarity was further elevated by the presence of the same following structural units, namely a methyl ester, a saturated ketone, two lactones, and both tri-and tetrasubstituted olefins, identified in a preliminary inspection of the NMR spectra of 1.…”

“…zsq2 (FJ545752), isolated from the marine sponge Plakortis simplex, aroused our interest as its EtOAc extract had numerous derivatives showing MS peaks at m/z = 400-500 in the medium polarity area and had a plethora of split 1 H NMR peaks in the aromatic region (see Figures S1 and S2 in the Supporting Information). Next, large-scale fermentation and separation by preparative medium-pressure liquid chromatography (MPLC) and HPLC led to the isolation of the previously reported 22-deoxyminiolutelide B (6), [8] preaustinoid A1 (7), [9] berkeleyone C (8), [10] berkeleyacetal A (9), [11] and preaustinoid A3 (10) [12] as well as five new meroterpenoids, eupeniacetal A (1), eupeniacetal B (2), 1-methoxy-hydropreaustinoid A1 (3), hydroberkeleyone B (4), and 22-deoxy-10-oxominiolutelide B (5; Figure 1). The structures and absolute configurations of these compounds were illuminated by virtue of detailed spectroscopic analysis, single-crystal X-ray diffraction, and TDDFT/ECD and [α] D calculations on solution conformers.…”

Aldgamycin I, an antibacterial 16-membered macrolide from the abandoned mine bacterium, Streptomyces sp. KMA-001

“…1 In the harsh conditions of an abandoned mine, microorganisms are likely to be subjected to substantial levels of competition, which could lead them to develop unique chemical arsenals, such as antibiotics. 2,3 In the course of our study on the production of secondary metabolites by the mine actinomycete, Streptomyces sp. KMA-001 was isolated from a heat-treated soil sample (55 1C, 5 min) collected at the Yeonhwa abandoned zinc mine in Korea.…”

Total Synthesis of Berkeleyamide A and its 10‐epi Isomer

“…R f = 0.38 (EtOAc/hexane, 8:92). 1 Berkeleyamide A (1a): To a solution of naphthalene (144 mg, 1.12 mmol) in dry THF (1.7 mL) was added Na (25 mg, 1.12 mmol) in small pieces. The mixture was stirred for 2 h at room temperature, and then it was added to a solution of 24 (43 mg, 0.093 mmol) in THF (2.2 mL) at -78°C until the green color persisted.…”

“…Stierle and co-workers identified more than 100 types of microbes in the lake that manage to survive in the unique, noxious ecosystem. [1] One of the first microbes to be studied was isolated from a water sample taken from a depth of 270 meters and identified as Penicillium rubrum Stoll. The organic extracts of this fungus contained several novel bioactive compounds, among which were berkeleyamide A-D. Berkeleyamide A (1a) was shown to exhibit activity against caspase 1 and MMP-3 in the low to submicromolar range (IC 50 = 0.33 µ).…”