Investigation of bioactive secondary metabolites from terrestrial Aspergillus oryzae sp. MMAO1 using M2 medium afforded a new diketopiperazine alkaloid, 7,9-dihydroxy-3-(1H-indol-3-ylmethyl)-8-methoxy-2,3,11,11a-tetrahydro-6H-pyrazino[1,2-b]isoquinoline-1,4-dione (1a), containing the unusual amino acid L-6,8-dihydroxy-7-methoxyphenylalanine. This was co-isolated with ditryptophenaline (2), cyclo-(Tryp,Tyr) (4), cyclo-(Pro,Val), α-cyclopiazonic acid (3), kojic acid and uridine. Re-cultivation of the fungal strain on Dox medium led to the production of bisdethio(bismethylthio)gliotoxin (5), pseurotin A (6) along with linoleic acid, α-cyclopiazonic acid (3) and kojic acid. The chemical structure of the new diketopiperazine alkaloid including the relative configuration was determined by 1D and 2D NMR spectroscopy and HR-ESI-MS spectrometry, and by comparison with the related literature. The new alkaloid (1a) showed no antimicrobial activity or cytotoxicity against brine shrimps.

The new chromophenazines A-F [9-methyl-5-(3'-methylbut-2'-enyl)-5H-benzo[a]phenazin-7-one (1a), 9-methyl-5-(3'-methylbut-2'-enyl)-7-oxo-5,7-dihydrobenzo[a]phenazine-1-carboxylic acid (1b), 5-(3'-methylbut-2'-enyl)-7-oxo-5,7-dihydrophenazine-1-carboxamide (2), 3-benzoyl-5-(3'-methylbut-2'-enyl)-5,10-dihydrophenazine-1-carboxylic acid (5a), 3,7-dibenzoyl-5-(3'-methylbut-2'-enyl)-5,10-dihydrophenazine-1-carboxylic acid (5b), and 3,7-dibenzoyl-5-(3'-methylbut-2'-enyl)-5,10-dihydrophenazine-1-carboxamide (5c)], together with phenazine-1-carboxylic acid, 1-phenazinecarboxamide, 1-phenazinol, tryptophol, and anthranilic acid, were isolated from Streptomyces sp. Ank 315. The structures of the new compounds were established on the basis of spectroscopic data, 1D NOE, 2D NMR, and ESIMS measurements and comparison with literature values.

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We present and discuss experim ental values o f the electric conductivity (and o f the density) for the liquid ternary system water + acetic acid + silver acetate at 25 °C. The results given here represent a selection from measurem ents on more than 200 com positions. The concepts o f equivalent condu ctivity and o f limitir.g values for infinite dilution in the ternary system are also dealt w ith briefly.We w ant to present an d to discuss th e results of m easurem ents of th e electric conductivity (and of th e density) of th e te rn a ry liquid system w ater -facetic acid + silver acetate a t 25 °C. Since our experim ents were carried out for m ore th a n I f we stipulate th a t th e only charged species present are H +, Ag+, and Ac-, we find for th e conductivity y. : where Z( denotes th e charge n um ber of ionic species i, Ci its concentration, A* its ionic con d u ctiv ity (product of F a ra d a y co n stan t an d m obility, w ater being th e reference substance), an d < X 2 or 0C 3 th e degree of dissociation of acetic acid (concentration C2 ) or of silver acetate (concentra tion C3 ), respectively. Defining an "equivalent co n d u ctiv ity " A byintroducing th e " equivalent fractions" X 2 and X 3 of acetic acid and silver acetate Aac -(x-2 X 2 + 0C 3 X 3 ) Aac~ (4) we derive from Eq. (1):The quantities A h , and Aac m ay be called the ionic conductivities of the ion constituents H, Ag, and Ac.In Table 1 we present a selection from our experim ental values of th e density (required for th e com putation of concentrations from mass fractions), of the conductivity, and of th e equivalent conduc tiv ity . Our m easurem ents cover th e range betw een infinite dilution and C2 = 0,5mol/1, C3 = 0,05mol/1 a t 25 °C. The d a ta include values for th e binary system s w ater -j-acetic acid (C3 = 0 ) and w ater + silver acetate (c2 = 0 ).