Melanin production inhibitors from the West African 'Cassipourea congoensis'

Cassipourea congoensis (syn. Cassipourea malosana) is used in African countries as a skin-lightening agent. Two previously unreported cycloartane triterpenoids, 26-hydroxy-3-keto-24-methy lenecycloartan-30-oic acid 1 and 24-methylene-cycloartan-3β,26,30-triol 2 along with the known mahuannin B 3, 7-methoxymahuannin B 4, 7-methoxygeranin A 5, methyl-3-(4-hydroxy-3-methoxyphenyl)-2E-propenoate, glycerol-1-alkanoate, (E)-3-(4-hydroxy-3-methoxyphenyl)prop-2-enal 6, (-)-syringaresinol 7, and stigmast-5-en-3-O-β-D-glucoside, were isolated from the roots of C. congoensis. The crude extract and compounds 1 and 5 were found to inhibit the production of melanin at 10 μM with low cytotoxicity validating the ethno-medicinal use of this plan

The INTEGRAL Galactic bulge monitoring program: the first 1.5 years

The Galactic bulge region is a rich host of variable high-energy point sources. Since 2005, February 17 we are monitoring the source activity in this region about every three days with INTEGRAL. Thanks to the large field of view, the imaging capabilities and the sensitivity at hard X-rays, we are able to present for the first time a detailed homogeneous (hard) X-ray view of a sample of 76 sources in the Galactic bulge region. We describe the successful monitoring program and show the first results for a period of about one and a half year. We focus on the short (hour), medium (month) and long-term (year) variability in the 20-60 keV and 60-150 keV bands. When available, we discuss the simultaneous observations in the 3-10 keV and 10-25 keV bands. Per visibility season we detect 32/33 sources in the 20-60 keV band and 8/9 sources in the 60-150 keV band. On average, we find per visibility season one active bright (>~100 mCrab, 20-60 keV) black-hole candidate X-ray transient and three active weaker (<~25 mCrab, 20-60 keV) neutron star X-ray transients. Most of the time a clear anti-correlation can be seen between the soft and hard X-ray emission in some of the X-ray bursters. Hard X-ray flares or outbursts in X-ray bursters, which have a duration of the order of weeks, are accompanied by soft X-ray drops. On the other hand, hard X-ray drops can be accompanied by soft X-ray flares/outbursts. We found a number of new sources, IGR J17354-3255, IGR 17453-2853, IGR J17454-2703, IGR J17456-2901b, IGR J17536-2339, and IGR J17541-2252. We report here on some of the high-energy properties of these sources. The high-energy light curves of all the sources in the field of view, and the high-energy images of the region, are made available through the WWW at http://isdc.unige.ch/Science/BULGE/.Comment: 27 pages, 42 figures, accepted for publication in A&A. Abstract abridged. Tables 3,4,6,7 appear at the end. Images have been compressed and are reduced in quality; original PostScript images can be retrieved from http://isdc.unige.ch/~kuulkers/bulge

Anti-leukaemic and anti-melanoma activities of homoisoflavonoids from Pseudoprospero firmifolium subsp. natalensis (Hyacinthaceae)

Five homoisoflavonoids, (3S)-3,5-dihydroxy-7‑methoxy‑3-(3′,4′-dimethoxybenzyl)-4-chromanone, 1, (3S)-3,5-dihydroxy-7,8-dimethoxy-3-(3′‑hydroxy‑4′‑methoxy)-4-chromanone, 2, (3R)-7,8-dimethoxy-5‑hydroxy‑3-(4′-hydroxybenzyl)-4-chromanone, 3, and (3R)-5‑hydroxy‑7‑methoxy‑3-(3′,4′-dimethoxybenzyl)-4-chromanone, 4, (3S)-3,5,7-trihydroxy-3-(3′‑hydroxy‑4′-methoxybenzyl)-4-chromanone, 5, and a spirocyclic nortriterpenoid, 29‑hydroxy‑15-deoxyeucosterol, 6, were isolated from the bulbs of Pseudoprospero firmifolium subsp. natalensis. Compounds 1, 2 and 5 were isolated previously from P. firmifolium subsp. firmifolium although configurations at C-3 were not established previously. Configurations at C-3 have been confirmed in this work for compounds 1–4 using ECD spectroscopy. The current findings for Pseudoprospero, and most especially of compound 3, indicate that the capacity of the Hyacinthoideae to synthesize homoisoflavonoids evolved prior to the divergence of the three extant tribes (Hyacintheae, Massonieae and Pseudoprospereae) ca. 18.8 Ma ago. Compound 5 displayed activity against two leukemia cell lines SR (GI50 = 0.64 μM) and K-562 (GI50 = 0.86 μM), and the melanoma MDA-MB-435 cell line (GI50=0.41 μM)

Organ-specific production of alkaloids from bulbs and seeds of Crinum stuhlmannii subsp. delagoense (Amaryllidaceae)

The phytochemistry of both bulbs and seeds of the ethnomedicinal Crinum stuhlmannii subsp. delagoense (Amaryllidaceae) was studied, sourced from a single location simultaneously. Eight alkaloids, including two previously unreported ones, N-methyl-haemanthamide (nivanine), and N-methyl-ent-delagoenine, were isolated along with lycorine, 8,9-methylenedioxophenanthridine, 6-hydroxycrinamine, 6-ethoxycrinamine, haemanthamine and hamayne. Compounds isolated were tested for acetylcholinesterase inhibition

Organ-specific production of alkaloids from bulbs and seeds of Crinum stuhlmannii subsp. delagoense (Amaryllidaceae)

The phytochemistry of both bulbs and seeds of the ethnomedicinal Crinum stuhlmannii subsp. delagoense (Amaryllidaceae) was studied, sourced from a single location simultaneously. Eight alkaloids, including two previously unreported ones, N-methyl-haemanthamide (nivanine), and N-methyl-ent-delagoenine, were isolated along with lycorine, 8,9-methylenedioxophenanthridine, 6-hydroxycrinamine, 6-ethoxycrinamine, haemanthamine and hamayne. Compounds isolated were tested for acetylcholinesterase inhibition

Vasorelaxing Activity of Stilbenoid and Phenanthrene Derivatives from Brasiliorchis porphyrostele: Involvement of Smooth Muscle Ca V12 Channels

Five compounds, 3,4′-dihydroxy-3′,5,5′-trimethoxydihydrostilbene, 1; 3,4′-ihydroxy-3′,5′-dimethoxydihydrostilbene, 2; 3,4′-dihydroxy-5,5′-dimethoxydihydrostilbene, 3; 9,10-dihydro-2,7-dihydroxy-4,6-dimethoxyphenanthrene, 4; and the previously unreported 1,2,6,7-tetrahydroxy-4-methoxyphenanthrene, 5 were isolated from the South American orchid, Brasiliorchis porphyrostele. An in-depth analysis of their vascular effects was performed on in vitro rat aorta rings and tail main artery myocytes. Compounds 1 - 4 were shown to possess vasorelaxant activity on rings pre-contracted by the α 1 receptor agonist phenylephrine, the Ca V 1.2 stimulator (S)-(-)-Bay K 8644, or depolarized with high K + concentrations. However, compound 5 was active solely on rings stimulated by 25 mM but not 60 mM K +. The spasmolytic activity of compounds 1 and 4 was significantly affected by the presence of an intact endothelium. The K ATP channel blocker glibenclamide and the K V channel blocker 4-aminopyridine significantly antagonized the vasorelaxant activity of compounds 4 and 1, respectively. In patch-clamp experiments, compounds 1 - 4 inhibited Ba 2+ current through Ca V 1.2 channels in a concentration-dependent manner, whereas neither compound 4 nor compound 1 affected K + currents through K ATP and K V channels, respectively. The present in vitro, comprehensive study demonstrates that Brasiliorchis porphyrostele may represent a source of vasoactive agents potentially useful for the development of novel antihypertensive agents that has now to be validated in vivo in animal models of hypertension

Ent-clerodane and ent-trachylobane diterpenoids from Croton dictyophlebodes.

The stem bark and root bark extracts of Croton dictyophlebodes (Euphorbiaceae) yielded seven undescribed ent-clerodanes: 15,16-epoxy-17,12(S)-olide-ent-cleroda-1,3,13(16),14-tetraen-18-oic acid methyl ester (crotodictyo A), 3β,4β:15,16-diepoxy-ent-cleroda-13(16),14-dien-20-al (crotodictyo B), 3β,4β:15,16-diepoxy-ent-cleroda-13(16),14-dien-19,20-dioic acid (crotodictyo C), 3β,4β:15,16-diepoxy-ent-cleroda-13(16),14-dien-20,19-olide (crotodictyo D), 3β,4β:15,16-diepoxy-20,12(R)-olide ent-cleroda-13(16),14-dien-19-oic acid methyl ester (crotodictyo E), 15,16-epoxy-ent-cleroda-3,13(16),14-trien-12-oxo-18-oic acid (crotodictyo F) and 15,16-epoxy-ent-cleroda-1,3,13(16),14-tetraen-12-oxo-18-oic acid (crotodictyo G), in addition to 15,16-epoxy- ent-cleroda-3,13(16),14-trien-12-oxo-18-oic acid methyl ester (crotodictyo H), reported previously as a synthetic derivative, and acetyl aleuritolic acid. The root extract yielded two ent-trachylobanes, ent-trachylobane-18,19-diol, the undescribed ent-trachylobane-2α,19-diol, along with ent-kaur-16-en-19-oic acid and 2-methoxybenzyl benzoate. Compounds were evaluated against the NCI 60 panel of human tumour cell lines at a single dose of 10−5 M, but showed no significant activity

Terpenoids from Cameroonian Oxystigma mannii (Baill.) Harms

We describe two new terpenoids, 3″,5″-dihydroxycinnamoyl-3β,28,30-dihydroxylup-20(29)-ene (1) and 6S,9S-dihydroxycasbe-3E,7E,11E-trien-5,10‑dione (2) and ten known asperglaucide, aridanin, isoscopoletin, maslinic acid, ursolic acid, oleanolic acid, lupeol, sitosterol, stigmasterol and stigmasterol-glucoside from a West African, GuineoCongolian mangrove and strand forest tree, Oxystigma mannii (Baill.) Harms. The structures of the new compounds were determined based on their 1D and 2D NMR, HRMS and FTIR. DP4+ probabilities were used to assign the configurations for compound 2. The two compounds were tested for their antimicrobial effects against Saccharomyces cerevisiae (BY4743), Escherichia coli (BW25113) and Bacillus subtilis (BY4743), but no inhibition was observed at the maximum concentrations tested (800 µM)