Four new prenylated flavonoids and xanthones from the root bark of Artocarpus nobilis.

Chemical investigation of the n-butanol extract from the methanol extract of the root bark of Artocarpus nobilis furnished four new prenylated flavonoids together with artonin E 2'-methylether (4), isoartonin E 2'-methylether (5), dihydroisoartonin E 2'-methylether (6), artonin V 2'-methylether (7), artobiloxanthone (1), artonin E (2) and cycloartobiloxanthone (3). All these compounds showed strong radical scavenging properties towards DPPH radical.

Dihydrochalcones with radical scavenging properties from the leaves of Syzygium jambos.

Chemical investigation of the dichloromethane extract of the leaves of Syzygium jambos furnished three dihydrochalcones, phloretin 4'-O-methyl ether (2',6'-dihydroxy-4'-methoxydihydrochalcone) (1), myrigalone G (2',6'-dihydroxy-4'-methoxy-3'-methyldihydrochalcone) (2), and myrigalone B (2',6'-dihydroxy-4'-methoxy-3,5'-dimethyldihydrochalcone) (3) with radical scavenging properties towards the DPPH radical by spectrophotometric method.

(2-Nitro ethyl)phenyl and cyanophenyl glycosides from the fruits of Diploclisia glaucescens.

Chemical investigation of polar fractions of the methanol extract of the fruits of Diploclisia glaucescens of the family Menispermaceae furnished two new phenyl glycosides, 4-(2-nitroethyl)phenyl-beta-D-xylopyranosyl-(l approximately 6)-beta-D-glucopyranoside, and 4-cyanophenyl-beta-D-xylopyranosyl-(l approximately 6)-beta-D-glucopyranoside.

Steroidal and triterpenoidal saponins from the fruits of Diploclisia glaucescens.

Chemical investigation of methanol extract of the fruits of Diploclisia glaucescens furnished 3-O-beta-D-glucopyranosyl-20-hydroxyecdysone, 3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl]serjanic acid 28-O-beta-D-glucopyranosyl ester and 3-O-[beta-xylopyranosyl(1-->2)-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl]serjanic acid 28-O-beta-D-glucopyranosyl ester. The latter saponin was found to be a new natural product while the other two are reported for the first time from the family Menispermaceae.

Glycosides from Grewia damine and Filicium decipiens.

Chemical investigation of n-butanol extract from the methanol extract of leaves of Grewia damine furnished lupeol, sitosterol beta-D-glucoside, flavone C-glycosides vitexin, isovitexin where as the same extracts from the leaves of Filicium decipiens furnished sitosterol beta-D-glucoside, 3-O-beta-D-glucopyranosyl kaempferol, 3-O-beta-D-glucopyranosylquercetin and 3-O-alpha-L-rhamnopyranosyl(1--> 2)-beta-D-glucopyranosylkaempferol.

Stilbene derivatives with antifungal and radical scavenging properties from the stem bark of Artocarpus nobilis.

Antifungal activity-guided fractionation of the n-butanol extract from the methanol extract of the stem bark of Artocarpus nobilis furnished two stilbene derivatives (E)-4-isopentenyl-3,5,2',4'-tetrahydroxystilbene and (E)-4-(3-methyl-E-but-1-enyl)-3,5,2',4'-tetrahydroxystilbene. Both compounds showed strong antifungal activity against Cladosporium cladosporioides and high radical scavenging activity towards the DPPH radical in TLC bio-autography method.

Nematicidal activity of some Sri Lankan plants.

Nineteen solvent extracts from seven Sri Lankan plants were examined for nematicidal activity against the root knot nematode Meloidogyne incognita. Extracts of Allophyhu cobbe, Lepisanthes tetraphylla (Sapindaceae), Sarcococca zeylanica (Buxaceae) and Hedyotis lawsoniae (Rubiaceae) have shown significant nematicidal activity.

Antifeedant activity of some Sri Lankan plants.

Twenty nine solvent extracts from twenty Sri Lankan plants were examined for antifeedant activity against the fourth instar larvae of Mexican bean beetle, Epilachna varivestis Muls., Coccinellidae. Extracts of Sarcococca brevifolia (Buxaceae), Strychnus nux vomica (Loganiaceae), Diploclisia glaucescens, Coscinium fenestratum (Menispermaceae), Syzygium caryophyllatum (Myrtaceae), Pittosporium zeylanicum (Pittosporaceae), Lasianthus gardneri (Rubiaceae), Ferronia limonia (Rutaceae) and Allophylus cobbe (Sapindaceae) have shown strong antifeedant activity.

Oleanane glycosides from the leaves of Diploclisia glaucescens.

Complete 1H and 13C NMR assignments are described for two known oleanane glycosides, 3-O-beta-D-glucopyranosyl(1-->3)-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyloleanolic acid and 3-O-beta-D-xylopyranosyl(1-->2)-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl oleanolic acid isolated from the methanol extract of the leaves of Diploclisia glaucescens.

Antimicrobial activity of some Sri Lankan Rubiaceae and Meliaceae.

Ninety solvent extracts (n-hexane, dichloromethane and methanol) obtained from the leaves, bark and stem of 13 Sri Lankan Rubiaceae and two Sri Lankan Meliaceae plants have been screened for antibacterial and antifungal activities. Morinda tinctoria, Mussaenda frondosa, Psychotria gardneri and Psychotria stenophylla displayed the widest spectrum of antibacterial activity.

A new norneohopane caffeate from Filicium decipiens.

Investigation of the dichloromethane extract of the stem of Filicium decipiens yielded a new natural product, 24-norneohopa-4(23),22(29)-diene-3beta,6beta,7beta-triol 7-caffeate (1).

24-Methylenecycloartenone from Bhesa nitidissima.

Complete (1)H and (13)C-NMR assignments are reported for 24-methylenecycloartenone (1) isolated from the stem of Bhesa nitidissima.

Iso-N-formyl-5-en-chonemorphine, a steroidal alkaloid from Sarcococca zeylanica.

Chemical investigation of the non-quaternary alkaloidal fraction of the aerial parts of Sarcococca zeylanica of the family Buxaceae furnished a steroidal alkaloid iso-N-formyl-5-en-chonemorphine, which has not been previously reported as a natural product. The structure of this alkaloid was established on the basis of spectroscopic evidence.

Triterpenoidal Constituents of Diploclisia glaucescens.

The pentacyclic triterpenoids serjanic acid and phytolaccagenic acid as well as a new glycoside, 3- O-beta- D-glucopyranosylphytolaccagenic acid have been isolated from the stem of DIPLOCLISIA GLAUCESCENS (Bl.) Diels (Menispermaceae). New spectroscopic data are furnished for serjanic acid and phytolaccagenic acid.