Two new furoquinoline alkaloids, maculine B (1) and kokusaginine B (2) and one new dihydrooxazole alkaloid, veprisazole (3), along with four known compounds namely, N13-methyl-3-methoxyrutaecarpine (4), flindersiamine (5), skimmianine (6) and tilianin (7) were isolated from the methanol extract of the stem bark of Araliopsis soyauxii Engl. by various chromatographic methods. Their structures were determined using spectrometry and spectroscopic techniques including NMR and MS. The cytotoxicity of the new compounds compared to that of doxorubicin, the reference anticancer compound, was determined on a panel of nine cancer cell lines including sensitive and drug resistant phenotypes. The three previously undescribed alkaloids displayed selective activities. Maculine B (1), the most active one among the newly described compounds, exhibited IC50 below 30 μM against CCRF-CEM leukemia and U87MG glioblastoma cells.

Twenty compounds were isolated from the hydroethanolic extract of the stems of Siolmatra brasiliensis, five flavonoids, two lignans, one glucosyl phytosterol, seven nor-cucurbitacins, one new phenolic derivative named siolmatrin (1) and four new dammarane-type saponins named siolmatrosides II-V (2–5), the structures of the compounds were assigned by means of 1D and 2D NMR experiments and HRESIMS of the natural compounds and some acetyl derivatives. The effects of the crude hydroethanolic extract (SbExt) and the ethyl acetate fraction (SbEtAc) of Siolmatra brasiliensis stems on the formation of advanced glycation end-products (AGEs) were also investigated. In the in vitro model system of protein glycation using bovine serum albumin (BSA) and glucose, addition of SbExt or SbEtAc inhibited the formation of fluorescent AGEs, in parallel to minor levels of fructosamine (SbEtAc) and markers of tyrosine and tryptophan oxidation (SbExt and SbEtAc). Protein crosslinking, which represents changes of late stages of protein glycation, was reduced in the presence of SbExt and SbEtAc. Siolmatra brasiliensis stems seem to be a promising source of compounds having ability to prevent glycoxidation changes, arising as an interesting option to be studied as a complementary therapy for complications of diabetes.

In the search for bioactive natural products from the African flora, three previously undescribed compounds including one stilbene-coumarin derivative (1), one coumarin-carbinol (2) and one fatty glycoside (3) were isolated from the stem bark and leaves of Monotes kerstingii, together with sixteen known compounds (4–19). The structures of the isolated compounds were elucidated based on their NMR and MS spectroscopic data and by comparison of these data with those previously reported in the literature. Compounds 1–19 were screened for anthelmintic and antimicrobial activity. None of the compounds exhibited significant anthelmintic activity. However, compounds 4, 5, 8 and 14 displayed interesting antibacterial activity against B. subtilis at a concentration of 100 μM with respective inhibition percentages of 99, 79, 71 and 100%, respectively, compared to erythromycin used as positive control. In addition, at the same concentration, compound 6 showed remarkable antifungal activity against Septoria tritici with 93.6% growth inhibition and was found to be more active than the positive controls epoconazole and terbinafine displaying 76.6 and 84.3%, respectively.

Pyrofomins A-D, four polyoxygenated sesquiterpenoids have been isolated from the methanolic extract of the fruit bodies of Pyrofomes demidoffii. Their structures are elucidated by IR, HR-FTICR-MS, and 2D NMR spectroscopy. Furthermore, the cedrane carbon skeleton of pyrofomin A (1) is confirmed by X-ray crystallographic analysis. The sesquiterpenoids 1–4 show neither cytotoxicity against KB cells nor antimicrobial activity.

A new dihydroflavonol–flavonol biflavonoid derivative, named ericoside was isolated from the ethanol extract of the whole plant of Erica mannii along with the known flavonoid, taxifolin 3-O-α-l-rhamnopyranoside; and two readily available sterols (sitosterol, sitosterol 3-O-β-d-glucopyranoside). The isolation was performed using chromatographic methods and the structure of purified molecules were elucidated using spectroscopic techniques (e.g. MS, NMR) and by comparison with literature data. The crude ethanol extract, ericoside, and taxifolin 3-O-α-l-rhamnopyranoside were tested against ten Gram-negative bacteria including multidrug resistant clinical isolates using a broth microdilution method. The crude ethanol extract showed no noteworthy activity. Of the purified compounds, ericoside displayed moderate activity against the resistant Escherichia coli AG100 with a MIC of 64 μg/mL.

A series of 2-(acetamide-2-yl)-imidazolines (II) with 5 points of diversity were prepared by an Ugi-4CR–Staudinger–aza-Wittig-sequence starting from simple azidoalkylamines. The intramolecular aza-Wittig cyclization between the iminophosphane and the tertiary amide of the Ugi product (I) was effected by short microwave irradiation. Competitive cyclization to the secondary amide was not relevant, however, in some cases subsequent formation of the bicyclic ortho-amidines (III) was observed.

A one-pot procedure for the phosphorylation of alcohols provides the corresponding phosphate monoesters in improved yields. The protocol features the use of tetrabutylammonium hydrogen phosphate and trichloroacetonitrile, followed by purification of the crude product by flash chromatography on silica gel. The final step, cation exchange chromatography, affords the organophosphates as ammonium salts that are usually required for biochemical applications. The mechanism appears to be phosphate rather than alcohol activation by trichloroacetonitrile.

The synthesis and applications of 4-isocyanopermethylbutane-1,1,3-triol (IPB) as a new convertible isonitrile (isocyanide) for isocyanide-based multicomponent reactions (IMCRs) like Ugi, Ugi-Smiles, and Passerini reactions are described. The primary products obtained from these IMCRs can be converted into highly activated N-acylpyrroles, which upon treatment with nucleophiles can be transformed into carboxylic acids, esters, amides, alcohols, and olefins. In this sense the reagent can be seen as a neutral carbanion equivalent to formate (HO2C−), and carboxylates or carboxamides etc. (RNu-CO−).

Indazolones are medicinally relevant targets. Herein we disclose an improved synthesis to N′-(acetamido-2-yl)-substituted indazolones with four points of diversity introduced by Ugi-[M]-amination and -amidation. The ring closure can be achieved by either conventional palladium catalysis or with a ligandless copper protocol. When α-unbranched isocyanides were employed the sole cyclization products of the copper catalyzed reactions are the hitherto undescribed 2-hydroxy-3H-3,4a,9a-triaza-fluorene-4,9-diones.

A variety of 1,6-enynes were synthesized by an Ugi-reaction and further elaborated by a PdII/IV catalyzed oxidative cyclization to produce N-substituted 3-aza-bicyclo[3.1.0]hexan-2-ones. Different substitution patterns were tested to examine the scope and limitations of the amide tethered substrates.