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Eupenifeldin was isolated from cultures of Eupenicillium brefeldianum ATCC741 84 by extraction and crystallization.The compoundwas identified as a pentacyclic bistropolone on the basis of spectral data and its complete structure was established by single-crystal X-ray analysis. The compound is cytotoxic against the HCT-1 16 cell line and has in vivo antitumor activity in the P388 leukemia model.Ongoing efforts to find new natural products with antitumor activity led to isolation of a novel cytotoxic bistropolone from a culture broth produced by Eupenicillium brefeldianum ATCC74184. The active principle of this culture was purified to homogeneity and namedeupenifeldin. Its spectral data showed that the molecule had partial symmetry due to the presence of two identically substituted tropolone units each fused in the same mannerto dihydropyran rings. The complete structure and relative stereochemical relationships were determined by single crystal X-ray analysis. Only one naturally occuring bistropolone with cytotoxic activity, fusariocin C, has been described previously in the literature.1>2) It was isolated from the culture filtrate of Fusarium moniliforme and had cytotoxic and antitumor activities. Bistropolones madeby chemical synthesis have also been reported to possess antitumor activity.3) This report describes isolation, physico-chemical characterization, biological properties and the structure of eupenifeldin. Materials and Methods Spectral DataMass spectra in the FABmodewere obtained on a Kratos MS25using m-nitrobenzylalcohol as matrix. El spectra were recorded on a Finnigan TSQ70. A Shimadzu UV2100Uspectrophotometer was used for UVspectra and a Perkin-Elmer FTIR Model 1800 spectrometer for IR spectra. All NMRspectra were recorded in CDC13with a drop ofDMSO-d6on a Bruker Model AM-500spectrometer. Proton-proton coupling constants were obtained by selective irradiations, and carbon-proton one-bond coupling constants were measured in the proton coupled carbon spectrum.El mass spectrum: major peaks at m/z 548, 384, 366, 175, 137. IR-spectrum (KBr): 3440, 3260, 2950, 2870, 1630, 1595, 1530, 1445, 1425, 1395, 1280, 1178, 1150, 1082 cm"1. Fermentation ConditionsTo prepare an inoculum for the production phase, 4 rnl of the frozen vegetative stock were transferred to a 500-ml Erlenmeyer flask containing 100ml of vegetative mediumconsisting of soluble starch 0.5%, glucose 0.5%, fishmeat extract 0. 1 %, yeast extract 0.1 %, NZ-case 0.2%, sodium chloride 0.2% and calcium

The structure of sandramycin, a novel antitumor antibiotic, was established by spectroscopic analysis and chiral chromatography of its acid hydrolysate.It was determined to be a cyclic decadepsipeptide with a two-fold axis of symmetry and 3-hydroxyquinaldic acid as an appended chromophore.Sandramycin is a new antitumor antibiotic produced by a Nocardioides sp. (ATCC39419). Its production, isolation, characterization and biological properties were reported in a previous paper1}. The details of the structure determination and the assignment of chirality are described in this paper. Results and DiscussionBecause of the similarity in their antitumor activity, in their isolation pathway and in their chromatographic behavior, sandramycin was initially thought to be identical to luzopeptin A (formally called BBM-928)2~5). However, direct comparison of their UVand 1H NMRquickly dispelled this hypothesis. Their UVspectra were quite different and the XHNMRrevealed at least three differences between them. Proton coupling in the up field methyl signals of sandramycin suggested that the /Miydroxy-7V-methylvaline residue of luzopeptin A was missing and perhaps replaced by TV-methylvaline. A different chromophore was evident by the different UVspectra and by an additional aryl proton and missing aryl methoxy group in the *H NMRof sandramycin. Additional NMRresonances in the region of d 1.4 to 2.0 and the lack an acetyl group in sandramycin also suggested a difference at the tetrahydropyridazine residue of luzopeptin A. The identification and connection of the residues in sandramycin was accomplished by analysis of *H and 13C NMRdata and degradation studies. Residue IdentificationThe XHand 13C NMRdata of sandramycin are shown in Tables 1 and 2. From the^^H COSY and long-range 1H-1H COSYspectra6'7) the amino acids serine, glycine, sarcosine, 7V-methylvaline and pipecolic acid were readily identified by their respective spin systems as shown in Fig. 1. Similarly, the aromatic chromophore, 3-hydroxyquinaldic acid, was identified from the 1H-1H COSYand 1H-13C heteronuclear multiple-bond correlation (HMBC)8)spectra of sandramycin with the couplings shown in Amino Acid SequenceNuclear Overhauser effect9) and 1H-13C HMBC experiments were used to determine the