A series of new aromatic esters based on 4,16-pregnadiene-6,20-dione skeleton, namely 3β-benzoyloxy-4,16-pregnadiene-6,20-dione and 3β-furoyloxy-4,16-pregnadiene- 6,20-dione, which may be good inhibitors for the 5α-reductase enzyme and show high antiandrogenic activity, were synthesized starting from diosgenin. The structures of the steroids were characterized by elemental analysis, 1H NMR, 13C...

In the title compound, C(18)H(20)N(2)O(3), the dihedral angle between the indole ring system (r.m.s. deviation = 0.018 Å) and the hy-droxy-methyl-enepyrrolidine-2,4-dione plane (r.m.s. deviation = 0.036 Å) is 9.87 (7)°. The keto and enol groups are involved in an intra-molecular O-H⋯O hydrogen bond. An intra-molecular C-H⋯O inter-action also occurs. The sec-butyl group is disordered over two or...

The asymmetric unit of the title compound, C20H18O6 (systematic name: 1β,3β-dihy-droxy-2β-meth-oxyfuro[4',3',2':4,5,6]-18-norandrosta-8,11,13-triene-7,17-dione), a dihydro derivative of the fungal steroid viridin, contains two mol-ecules with similar conformations. The rings bearing the hy-droxy groups adopt boat conformations. The absolute structure was assigned based on the known chirality of...

Simple syntheses of the benzo-fused 26-membered macrocyclic bischalcone (19E,43E)-2.11.27.36-tetroxaheptacyclo[44.4.0.0(4,9).0(12,17).0(21,26).0(29,34).0(37,42)]pentaconta-1(46),4(9),5,7,12(17),13,15,19,21,23,25,29,31,33,37,39,41,43,47,49-icosaene-18,45-dione (3) and the benzo-fused 13-membered macrocyclic chalcone (19E)-2.11-dioxatetracyclo[19.4.0.0(4,9).0(12,17)]pentacosa-1(25),4(9),5,7,12(17...

Two new compounds, fumitremorgin 12-methoxy-13-[5'-hydroxy-2'-(1''-hydroxy-3''-methoxy-5''-methylbenzoyl)-3'-methoxy]benzoic acid methyl ester (fumitremorgin D, 1) and 4,8,10,14-tetramethyl-6-acetoxy-14-[16-acetoxy-19-(20,21-dimethyl)-18-ene]-phenanthrene-1-ene-3,7-dione (2) were isolated from the cultured endophytic isolated fungus Aspergillus fumigatus, together with fourteen known compounds....

The first total synthesis of (±)-renieramycin I, which was isolated from the Indian bright blue sponge Haliclona cribricutis, is described. The key step is the selenium oxide oxidation of pentacyclic bis-p-quinone derivative (3) stereo- and regioselectively. We also report a large-scale synthesis of cribrostatin 4 (renieramycin H) via the C3-C4 double bond formation in an early stage based on t...

The chromophore 3-Z phycocyanobilin (PCB, (2R,3Z)-8,12-bis(2-carboxyethyl)-18-ethyl-3-ethylidene-2,7,13,17-tetramethyl-2,3-dihydrobilin-1,19(21H,24H)-dione) mediates red and far-red light perception in natural and synthetic biological systems. Here we describe a PCB synthesis strategy in mammalian cells. We optimize the production by co-localizing the biocatalysts to the substrate source, by co...

The asymmetric unit of the title compound, C(22)H(18)N(2)O(2), contains two independent mol-ecules, which differ in the orientations of the benzyl groups with respect to the planar (r.m.s. deviations of 0.031 and 0.020 Å) quinazoline-2,4-dione skeletons [dihedral angles of 73.97 (4) and 70.07 (4)° in the first mol-ecule and 75.63 (4) and 63.52 (3)° in the second]. The crystal structure is stabi...

The sodium salts of some hetaryls of the quinoxalin-2-ones 2-4, phthalazine-1,4-dione 5, phthalazin-1-one 6, and pyridazin-6-ones 7 and 8 were alkylated with (+/-) 2,3-O-isopropylidene-1-O-(4-toluenesulfonyl)glycerol (1) to give the respective tetraseco-nucleosides 9-15. Their deisopropylidenation with 70% acetic acid in water gave the corresponding 2,3-dihydroxyprop-1-yl hetaryls 16-22. Compou...