Norditerpenoid alkaloids of Delphinium denudatum as cholinesterase inhibitors.

Three new norditerpenoids alkaloids, 1ß-hydroxy,14ß-acetyl condelphine (1), jadwarine-A (2), jadwarine-B (3) along with two known alkaloids isotalatizidine hydrate (4) and dihydropentagynine (5) were isolated from medicinal plant Delphinium denudatum. The structures of natural products 1-5 were established on the basis of HR-EIMS, 1H and 13C NMR (1D & 2D) spectroscopic data as well as by comparison from literature data. The structures of compound 1 and 4 were also confirmed by single crystal X-ray diffraction studies. In-vitro AChE and BChE enzyme inhibitory activities of compounds 1-5 and molecular docking studies were performed to investigate the possible molecular inhibitory mechanism of the isolated natural products. Compound 2, 4 and 5 showed competitive inhibitory effects by inhibiting AChE and BChE, respectively, while 1 and 3 showed non-competitive inhibition. This work is the first report that provides a supporting evidence about the use of constituents of Delphinium denudatum in cerebral dementia and Alzheimer diseases.

Chemical and pharmacognostical characterization of two Malaysian plants both known as Ajisamat

Ajisamat, an herb commonly used as an aphrodisiac in the Malaysian traditional medicine, corresponds to two different species from different families - Salacia macrophylla Blume, Celastraceae, and Prismatomeris glabra (Korth.) Valeton, Rubiaceae. Macromorphological inspection of the vegetative parts both plants reveals only a slight difference in the arrangement of the petioles. Microscopic investigation of the plants roots used as crude drugs revealed however distinctive anatomical features. Prismatic calcium oxalate crystals and banded paratracheal parenchyma are characteristics of S. macrophylla while P. glabra displays an abundance as crystals. Other features such as vessels diameters and arrangements are also of diagnostic importance. Some of these characters were also identified in the powder of thes e plant materials and proposed for diagnostic purpose. The values for extraction of ethanol and water as well as total ash, acid-insoluble ash, water-soluble ash and sulfated ash were determined for both plants. Phytochemical studies were carried out on hexane and chloroform extracts of S. macrophylla and methanolic extract of P. glabra. S. macrophylla was shown to contain highly oxidized pentacyclic triterpenes while P. glabra contains anthraquinones. The pharmacognostical and hytochemical information can be utilised as the identification tools for Salacia macrophylla and Prismatomeris glabra .

Stilbene glycosides are natural product inhibitors of FGF-2-induced angiogenesis.

BACKGROUND: Angiogenesis, the growth of new blood vessels from the pre-existing vasculature is associated with pathological processes, in particular tumour development, and is a target for the development of new therapies. We have investigated the anti-angiogenic potential of two naturally occurring stilbene glycosides (compounds 1 and 2) isolated from the medicinal plant Boswellia papyriferai using large and smallvessel-derived endothelial cells. Compound 1 (trans-4',5'-dihydroxy-3-methoxystilbene-5-O-{alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->6)}-beta-D-glucopyranoside was the more hydrophilic and inhibited FGF-2-induced proliferation, wound healing, invasion in Matrigel, tube formation and angiogenesis in large and small vessel-derived endothelial cells and also in the chick chorioallantoic membrane assay. Using a binding assay we were able to show compound 1 reduced binding of FGF-2 to fibroblast growth factor receptors-1 and -2. In all cases the concentration of compound 1 which caused 50% inhibition (IC50) was determined. The effect of compound 1 on EGF and VEGF-induced proliferation was also investigated. RESULTS: Compound 1 inhibited all stages of FGF-2 induced angiogenesis with IC50 values in the range 5.8 +/- 0.18 - 48.90 +/- 0.40 microM but did not inhibit EGF or VEGF-induced angiogenesis. It also inhibited FGF-2 binding to FGF receptor-1 and -2 with IC50 values of 5.37 +/- 1.04 and 9.32 +/- 0.082 muM respectively and with concommotant down-regulation of phosphorylated-ERK-1/-2 expression. Compound 2 was an ineffective inhibitor of angiogenesis despite its structural homology to compound 1. CONCLUSION: Compound 1 inhibited FGF-2 induced angiogenesis by binding to its cognate receptors and is an addition to the small number of natural product inhibitors of angiogenesis.

Bioactive constituents from Boswellia papyrifera.

Phytochemical investigation of the stem bark extract of Boswellia papyrifera afforded two new stilbene glycosides, trans-4',5-dihydroxy-3-methoxystilbene-5-O-{alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->6)]-beta-D-glucopyranoside (1), trans-4',5-dihydroxy-3-methoxystilbene-5-O-[alpha-L-rhamnopyranosyl-(1-->6)]-beta-D-glucopyranoside (2), and a new triterpene, 3alpha-acetoxy-27-hydroxylup-20(29)-en-24-oic acid (3), along with five known compounds, 11-keto-beta-boswellic acid (4), beta-elemonic acid (7), 3alpha-acetoxy-11-keto-beta-boswellic acid (8), beta-boswellic acid (9), and beta-sitosterol (10). The stilbene glycosides exhibited significant inhibition of phosphodiesterase I and xanthine oxidase. The triterpenes (3-9) exhibited prolyl endopeptidase inhibitory activities.