This study was designed to assess the cytotoxicity, anti-HIV and antibacterial efficacy of various solvent extracts of roots, stem and leaves of Alchornea laxiflora, as well as five compounds isolated from its methanolic stem extract viz.; ellagic acid (1); 3-O-methyl-ellagic acid (2), 3-O-beta-D-glucopyranosyl-beta-sitosterol (3), 3-O-acety-loleanolic acid (4) and 3-O-acetyl-ursolic acid (5). The tested crude extracts were prepared from several solvent polarities including: hexane (Hex), chloroform (CHCl3), ethyl acetate (EtOAc), ethanol (EtOH), methanol (MeOH) and water (H2O). The anti-HIV properties were assessed on HIV-1 subtype C integrase while the cytotoxicity was tested against Hela cells. The antibacterial activity was studied on a panel of pathogens including gastrointestinal, skin, respiratory and urinary-tract infection causing Gram positive bacteria viz.; Bacillus cereus (ATCC 11778), Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 25923) and Staphylococcus saprophyticus (ATCC 15305)] and Gram-negative bacteria, i.e., Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 13883), Moraxella catarrhalis (ATCC 23246). All the tested samples were determined to be non-toxic due to the low inhibitions observed. The most potent anti-HIV activity was observed for the methanolic extract of A. laxiflora root (ALR4) with an IC50 value of 0.21 ng/ml, which was more active than chicoric acid used as reference drug (6.82 nM). Roots, stem and leaves of A. laxiflora extracts exhibited antibacterial activities against most of the Gram-positive bacteria with the minimum inhibitory concentrations (MIC) ranging between 50 and 63 mu g/ml. Compounds 1-5 displayed antibacterial activities against S. saprophyticus with MIC values as low as 4 mu g/ml. The results inferred from this study demonstrate the potential of A. laxiflora root as a source for new anti-HIV drugs and scientifically validate the traditional use of A. laxiflora in the treatment of gastrointestinal, skin, respiratory and urinary tract related infections. These results reaffirm the ethnopharmacological significance of African traditional medicines. (C) 2018 SAAB. Published by Elsevier B.V. All rights reserved.

Propolis is a dark sticky material that bees (indispensable actors in biosphere) harvest from exudates and buds of plants alongside pollinating them, promoting agriculture and protecting the ecosystem. Its chemical composition is highly variable and dependent on the local flora. In search for rapid chemical screening methods which are capable of characterizing propolis samples from various geographic origins, various hyphenated techniques such as HPLC-DAD, HPLC-MS/MS, LC–MS, LC–MS/MS, GC–MS etc., have been used and giving an insight on the regional variation in chemical composition. Various chromatographic techniques (CC, UPLC, HLPC, RP-HPLC, TLC….) are used in obtaining organic bioactive compounds from propolis. The structures of these compounds are characterised using state-of-the-art spectroscopic and spectrometric methods. There is no clear-cut distinction of propolis from different regions but the major chemical compounds can be classified in two main groups as those from temperate propolis and those from tropical propolis. Compounds isolated from propolis from temperate regions are mostly flavones, flavonols, flavanones, flavanonols, chalcones, aurones, pterocarpans, lignans, phenolic acids and their esters, etc. Compounds isolated from propolis from tropical and subtropical regions are mostly terpenoids, steroids and xanthones. Propolis is very rich in structurally diverse molecules which are capable of being isolated. These compounds/potential drugs are usually subjected directly to bioassays or used as starting material for synthesis in view of obtaining their derivatives or synthetic analogues with enhanced biological activities.

The aim of this study was to isolate, to characterize secondary metabolites from methanolic extract of the root woods of Erythrina droogmansiana and to assess the antioxidant activity of the crude extract and isolated compounds. The phytochemical study led to the isolation of 3-(3’,4’-methelenedioxyphenyl)-2,3-epoxypropanol (1), asperphenamate (2) and three flavonoids namely genistein, diadzein and 4’,5,7-trihydroxy-8-prenylisoflavone. These compounds were characterized using their 1H NMR, 13C NMR, HMBC, HSQC, COSY, mass spectral and the literature. To evaluate antioxidant activity of crude extract and isolated compounds, the radical scavenging (DPPH) and Ferric Reducing Ability Power (FRAP) were performed using ascorbic acid as standard. Compounds 1 and 2 showed moderate radical scavenging potential with IC50 value of 3.14 and 3.31 mg/ml respectively, and moderate reducing power ability with value of 0.14±0.01 mgAAE/mg and 0.21±0.01 mgAAE/mg respectively. The more active compound was genistein (3) with IC50 value of 1.96 mg/ml for the DPPH radical scavenging potential and 0.24±0.02 mgAAE/mg for its ability to reduce iron.

A newxanthone derivative, Cordixanthone (1-hydroxy-3,6-dimethoxy-7- methylxanthen-9-one) (1) and seven known compounds, were isolated from Cordia platythyrsa. This is the first time, xanthones are reported from the genus Cordia. Methyl orsellinate and lichexanthone were tested against the urease enzyme and methyl orsellinate was evaluated for in vitro antiglycation activity. Methyl orsellinate was found active for both of the test whereas lichexanthone showed no activity.

Eight compounds were isolated from the CH2Cl2 extracts of Erythrina senegalensis to assess HIV-1 protease (PR) activity inhibition. The prenylated isoflavone structures, identified by spectroscopic analysis, were 8-prenylluteone (1), auriculatin (2), erysenegalensein O (3), erysenegalensein D (4), erysenegalensein N (5), derrone (6), alpinumisoflavone (7), and 6,8-diprenylgenistein (8). The constituents showed dose-dependent inhibitory activities on HIV-1 PR with IC50 values from 0.5 to 30.0 mu M. Compounds 1-5 possessing two hydroxy groups in the 2' and 4' positions of the B ring, potently inhibited HIV-1 PR activity. In addition, 6,8-diprenylgenistein (8) with two prenyl groups in the 6 and 8 positions of the A ring and one hydroxy group in the 4' position of B-ring was the most potent HIV-1 PR inhibitor.

A cacalolide derivative named 4α-[2′-hydroxymethylacryloxy]-1β-hydroxy-14-(5→6) abeo eremophilan-12,8-olide and a shikimic acid derivative named (3′E)-(1α)-3-hydroxymethyl-4β,5α-dimethoxycyclohex-2-enyloctadec-3′-enoate along with three known compounds, octacosan-1-ol, 3β-hydroxyolean-12-en-28-oic acid and 3β-acetoxyolean-12-en-28-oic acid were isolated from Senecio burtonii. Their structures and relative configurations were established on the basis of spectroscopic analysis.

In addition to one known compound, 3 beta, 8 alpha-dihydroxyguaian- 4(15), 10(14), 11(13)- trien-6,12 olide (8-desacylcynaropicrin) ( 3), two new sesquiterpene lactones have been isolated from the aerial parts of Crepis cameroonica. By means of spectroscopic analysis, the structures and relative configurations of the new compounds were established as 3 beta, 9 beta-dihydroxyguaian4( 15), 10( 14), 11( 13)- trien-6,12 olide ( 1) and 8 alpha-hydroxy-4 alpha( 13), 11 beta(15)-tetrahydrozaluzanin C (2). The in vitro antimicrobial spectrum of pure compounds and crude extracts are also reported.

Two prenylated flavanones isolated from Erythrina sigmoidea Hua (sigmoidin A and sigmoidin B) were studied for their ability to inhibit the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical and arachidonic acid metabolism. In addition, the compounds were studied in two experimental models of inflammation induced in mouse ears by 12- O-tetradecanoylphorbol 13-acetate (TPA) and the phospholipase A (2)-induced mouse paw oedema. Both sigmoidins A and B proved to be potent scavengers of the DPPH radical, while the study of the inhibition of arachidonic acid metabolism demonstrated that these same compounds were selective inhibitors of 5-lipoxygenase, with no effect on cyclooxygenase-1 activity. Dose-response inhibitor potency was established for sigmoidin A (IC (50) = 31 microM). In the assay of phospholipase A (2)-induced mouse paw oedema, only the sigmoidin B derivative inhibited oedema formation at 60 min, showing a percentage of inhibition below that obtained with cyproheptadine (59 % vs. 74 %). In the TPA test, sigmoidins A and B decreased the induced oedema by 89 % and 83 %, respectively. This is the first time that the anti-inflammatory activity and antioxidant properties of these prenylflavanones have been reported. The results indicate that the compounds have different mechanisms of action depending on whether one or two prenyl groups are present in ring B.

The prenylisoflavone warangalone has been isolated from the bark of Erythrina addisoniae. This compound, previously recognized as a powerful inhibitor of protein kinase A, showed marked effectiveness as an anti-inflammatory on the phospholipase A(2)-induced paw edema and on the 12-O-tetradecanoylphorbol 13-acetate-induced ear edema in mice, after systemic and local administration, respectively.

Conjugate addition of the imino nitrogen of 2-aminobenzothiazoles 1 to the alkyne beta-carbon atom of acetylenic acids 2 followed by ring closure gives rise to novel 2H-pyrimido[2,1-b]-benzothiazol-2-ones in good yield.

Erycristagallin, a pterocarpene isolated from Erythrina mildbraedii, was tested in vitro for its antioxidant properties on the stable 2,2-diphenyl-1-pycryl-hydrazyl (DPPH) free radical and on the arachidonic acid metabolism. In addition, erycristagallin was tested on different experimental models of inflammation, such as the acute and chronic inflammation induced by the application of 12-O-tetradecanoylphorbol 13-acetate (TPA) on mice and the phospholipase A2-induced mouse paw oedema test. In the carrageenan-induced mouse paw oedema test, the ethyl acetate extract obtained from E. mildbraedii showed anti-inflammatory activity, and erycristagallin was isolated as the active principle. In vivo, erycristagallin significantly inhibited the phospholipase A2-induced mouse paw oedema as well as the mouse ear oedema induced by TPA (ID50<10 μg/ear). Moreover, it significantly reduced the chronic inflammation and leukocyte infiltration induced by repeated application of TPA. In vitro, erycristagallin inhibited the arachidonic acid metabolism via the 5-lipoxygenase pathway in rat polymorphonuclear leukocytes (IC50=23.4 μM), but had no effect on cyclooxygenase-1 metabolism in human platelets, while showing antioxidant activity in the DPPH test. As with other phenolics, the anti-inflammatory activity of erycristagallin may be based on its capacity to inhibit the arachidonic acid metabolism via the 5-lipoxygenase pathway.

Methanol, ethyl acetate, and hexane extracts of Bridelia ferruginea leaves exhibited significant activity against Pseudomonas frutescens, Bacillus subtilis, Echerichia coli, Staphylococcus aureus and Streptococcus faecalis.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The reaction of allenic nitriles with 2-aminobenzimidazoles gives 2-aminopyrimido[1,2-a]benzimidazoles 5 in very good yields. The pharmacological screening of compound 5a, 5d and 5i shows that they possess slight antibiotic and antiarrythmic properties.

Three new isoflavonoids, griffonianone A (1), B (2) and C (1, Fig. 1) were isolated from the root bark of Millettia griffoniana, along with the known maximaisoflavone G (5) and 7-hydroxy-6-methoxy-3′,4′-methylenedioxyisoflavone (6). Their structures were assigned on the basis of spectroscopic data and chemical transformations.

Two prenylated isoflavonoids, erysenegalensein N, 5,7,2',4'-tetrahydroxy-6-(2"-hydroxy-3"-methylbut-3"-enyl)-8-(gamma,gamma- dimethylallyl) isoflavone and erysenegalensein O, 5,2',4-trihydroxy-6-(gamma,gamma-dimethylallyl)-3'''-hydroxy-2''', 2'''-dimethyldihydropyrano[5''',6"';8,7]isoflavone, in addition to six known compounds were isolated from the ste bark of Erythrina senegalensis (Leguminosae). Their structures were elucidated by spectroscopic methods. (C) 1999 Elsevier Science Ltd. All rights reserved.

Auriculatin and 8-prenylluteone were isolated from Erythrina senegalensis (Leguminosae) as inhibitors of phospholipase C (PLC) and phosphoinositides (PI)-turnover in PLC-gamma 1 overexpressing NIH3T3 fibroblasts (NIH3T3 gamma 1). Auriculatin (1) and 8-prenylluteone (2) showed inhibitory activity with an IC50 value of 20 mu M on PLC in vitro as well as the formation of inositol phosphates in platelet-derived growth factor (PDGF)-stimulated NIH3T3 gamma 1 cells. They also showed a moderate cytotoxicity against several human tumour cell lines with an IC50 of 9.0-20 mu M, i.e. PC-3 (prostate), NCI-H226 (lung), CRL1579 (melanoma) in vitro. (C) 1998 John Wiley & Sons, Ltd.

Two new triterpenoid saponins, designated sigmoside C and D, have been isolated from the methanol extract of the stem bark of Erythrina sigmoidea in addition to the known soyasapogenol-B and 3-O-[β-d-glucopyranosyl]-sitosterol. The structures of the saponins were determined by chemical and spectroscopic means as 22-O-[β-d-glucopyranosyl]-soyasapogenol-B and 22-O-[α-l-rhamnopyranosyl]-soyasapogenol-B, respectively.

Two new triterpenoid saponins, designated sigmoside C and D, have been isolated from the methanol extract of the stem bark of Erythrina sigmoidea in addition to the known soyasapogenol-B and 3-O-[beta-D-glucopyranosyl]-sitosterol. The structures of the saponins were determined by chemical and spectroscopic means as 22-O-[beta-D-glucopyranosyl]-soyasapogenol-B and 22-O-[alpha-L-rhamnopyranosyl]-soyasapogenol-B, respectively. Copyright (C) 1997 Elsevier Science Ltd.