Two new diterpenoids from Ballota limbata.

Two new clerodane-type diterpenoids trivially named as ballotenic acid (1) and ballodiolic acid (2) have been isolated from Ballota limbata along with three the known compounds; beta-amyrin, oleanolic acid, and beta-sitosterol. The structure elucidation of the new compounds was based primarily on two-dimensional (2D)-NMR techniques including correlation spectroscopy (COSY), heteronuclear multiple quantum coherence (HMQC), heteronuclear multiple bond correlation (HMBC), and nuclear Overhauser effect (NOE) experiments. Compounds 1 and 2 displayed inhibitory potential against lipoxygenase enzyme in a concentration-dependent fashion with IC(50) values of 99.

Biscoumarin: new class of urease inhibitors; economical synthesis and activity.

A variety of biscoumarins (1-21) with variable substituents at C-11 were synthesized with an improved method and evaluated as urease inhibitors. The synthesized compounds showed varying degree of urease inhibitory activity ranging from 15.06-91.

In vitro anti-inflammatory effect of Carthamus lanatus L.

The anti-inflammatory activity of four total extracts, their fractions and two main constituents (alpha-bisabolol beta-D-fucopyranoside and luteolin 7-O-glucoside) of Carthamus lanatus L. aerial parts, were assessed in vitro by determining the inhibitory effects on induced human neutrophils. The dichloromethane extract and its water-alcoholic part exhibited the most significant inhibitory effects.

First natural urease inhibitor from Euphorbia decipiens.

Three new diterpene esters with a myrsinol-type skeleton have been isolated from Euphorbia decipiens BOISS. & BUHSE. The structure elucidation of the isolated compounds was based primarily on two-dimensional (2D)-NMR techniques including correlation spectroscopy (COSY), heteronuclear multiple quantum coherence (HMQC), heteronuclear multiple bond correlation (HMBC) and nuclear Overhauser effect spectroscopy (NOESY) experiments.

Cholinesterase inhibitory constituents from Onosma hispida.

Hispidone, a new flavanone, has been isolated from Onosma hispida and assigned the structure (2S)-5,2'-dihydroxy-7,4',5'-trimethoxyflavanone (1) by spectroscopic methods. In addition, (2S)-5,2'-dihydroxy-7,5'-dimethoxyflavanone (2), benzoic acid (3), and 4-hydroxy benzoic acid (4) are also reported for the first time from this species.

Paeonins A and B, lipoxygenase inhibiting monoterpene galactosides from Paeonia emodi.

Paeonins A and B, new monoterpene galactosides have been isolated from the chloroform-soluble fraction of the roots of Paeonia emodi and showed potent lipoxygenase inhibitory activity. The structures of 1 and 2 have been assigned on the basis of spectral analysis including one- and two-dimensional NMR techniques.

Two new rearranged taxoids from Taxus wallichiana ZUCC.

Two new rearranged taxane diterpenoids, 5alpha,7beta,10beta,13alpha-tetrahydroxy-2alpha,9alpha,15-triacetoxy-11(15-->1)-abeo-taxa-4(20), 11-diene (1) and 5alpha,9alpha,10beta,13alpha-tetraacetoxy-15-hydroxy-11(15-->1)-abeo-taxa-4(20), 11-diene (2) have been isolated from the barks of Taxus wallichiana. The structures of these compounds have been confirmed by modern spectroscopic techniques.

Beta-N-cyanoethyl acyl hydrazide derivatives: a new class of beta-glucuronidase inhibitors.

Eight new beta-N-substituted acyl hydrazides along with their corresponding acyl derivatives were synthesized and screened for in vitro beta-glucuronidase inhibition and found to be active against the enzyme. All of these compounds were found to be noncompetitive inhibitors except for N'-(2-cyanoethyl)-4-hydroxy benzohydrazide (10), which was found to be an uncompetitive inhibitor. Structure-activity relationship studies indicated that the benzyloxy group present in compounds 12 and 13 is responsible for the beta-glucuronidase inhibition activity.

New cholinesterase inhibiting steroidal alkaloids from the leaves of Sarcococca coriacea of Nepalese origin.

From the leaves of Sarcococca coriacea two new steroidal alkaloids, epoxynepapakistamine-A [(20S)-20-(N-methylamino)-3beta-(tigloylamino)-5alpha-pregna-16alpha,17alpha-epoxy-2beta,4beta-di-O-acetate] (1), and epoxysarcovagenine-D [(20S)-20-(N-methylamino)-3beta-(tigloylamino)-5alpha-pregna-2-en-16alpha,17alpha-epoxy-4-one] (2), and two known compounds funtumafrine C [(20S)-20-(N,N-dimethylamino)-5alpha-pregna-3-one] (3) and N-methylfuntumine (4) were isolated. Their structures were elucidated on the basis of their spectral properties. The compounds 1, 3 and 4 were found to have cholinesterase inhibitory activity when tested for the inhibition of electric eel acetylcholinesterase and horse serum butyrylcholinesterase.

Two new cinnamic acid esters from Marine brown alga Spatoglossum variabile.

Two new natural products, n-butyl and isopropyl 3,5-dimethoxy-4-hydroxycinnamate were isolated from Spatoglossum variabile. Three known compounds, methyl 3,4,5-trihydroxybenzoate, 2-deoxyinosine and 9-beta-(D-ribofuranosyl)adenine were isolated for the first time from the methanolic extracts of this alga. The structure elucidations of the new compounds were carried out with the help of modern spectroscopic techniques.

Isoflavonoid glycosides from the rhizomes of Iris germanica.

Four isoflavone glycosides were isolated from the rhizomes of Iris germanica. Compounds 1 and 2 are new, while compounds 3 and 4 are known isoflavone glycosides. These compounds were identified as iriskashmirianin 4'-O-beta-D-glucoside (1), nigricin 4'-O-beta-D-glucoside (2), irilone 4'-O-beta-D-glucoside (3) and iridin (4).

New steroidal alkaloids from Fritillaria imperialis and their cholinesterase inhibiting activities.

Two new cevanine steroidal alkaloids, impericine (1) and forticine (2) along with known bases delavine (3), persicanidine A (4), and imperialine (5) were isolated from the bulbs of Fritillaria imperialis. The structures of impericine (1) [(20R,22S,25S)-5alpha-cevanin-23-ene-3beta,6beta,16beta-triol] and forticine (2) [(20S,22S,25S)-5alpha-cevanine-3beta,6beta-diol] were determined with the help of spectroscopic studies. These steroidal bases showed anti-acetylcholinesterase and anti-butyrylcholinesterase inhibitory activity.

Structure-activity relationship of triterpenoids isolated from Mitragyna stipulosa on cytotoxicity.

Chromatographic separation of the stem bark extract of Mitragyna stipulosa afforded triterpene derivatives ursolic acid (1), quinovic acid (2), quinivic acid 3-O-beta-D-glucopyranoside (3, quinovin glycoside C), quinovic acid 3-O-[(2-O-sulfo)-beta-D-quinovopyranoside] (4, zygophyloside D) and quinovic acid 3-O-beta-D-quinovopyranosyl-27-O-beta-D-glucopyranosyl ester (5, zygophyloside B). These five compounds were subjected to the cytotoxicity on MTT assay system. Compound 1 among tested showed the most potent cytotoxicity.

Inhibition of alpha-glucosidase by oleanolic acid and its synthetic derivatives.

Oleanolic acid (1) and five synthetic derivatives (2-6) were tested spectrophotometrically for inhibition of urease, beta-lactamase, acetyl cholinesterase and alpha-glucosidase. All products showed a positive response only against alpha-glucosidase but not against the other enzymes; IC(50) calculations showed that the dihydroxy-olide derivative (4) was the most potent among all tested samples.

First direct discrimination of chiral phosphine selenide (P=Se) derivatives by multinuclear magnetic resonance spectroscopy in the presence of a chiral dirhodium complex.

Enantiomeric ratios of compounds with P=Se functionalities (phosphine selenides) can easily be determined by (1)H, (13)C, (31)P, and (77)Se NMR spectroscopic inspection of their diastereomeric complexes with (R)-Rh(2)(MTPA)(4) (MTPA-H identical with methoxytrifluoromethylphenylacetic acid; Mosher's acid). This is the first facile and rapid spectroscopic method for chiral recognition in this class of compounds. Whereas most complexation shifts Delta(delta) are moderate or even negligible, significant signal dispersions Delta(nu) can be observed.

A new coumarin from Murraya paniculata.

A new natural product, 2'-O-ethylmurrangatin (1) was isolated along with two previously known compounds murranganone (2) and paniculatin (3) from the leaves of Murraya paniculata. The structure of compound 1 was elucidated with the help of spectroscopic studies and by chemical reactions. Compounds 2 and 3 have been found to be cholinesterase inhibitors.

Alpha-glucosidase inhibitory constituents from Cuscuta reflexa.

Two new compounds, 7'-(3',4'-dihydroxyphenyl)-N-[(4-methoxyphenyl)ethyl]propenamide (4), and 7'-(4'-hydroxy,3'-methoxyphenyl)-N-[(4-butylphenyl)ethyl]propenamide (5) have been isolated from Cuscuta reflexa along with five known compounds, 6,7-dimethoxy-2H-1-benzopyran-2-one (1), 3-(3,4-dihydroxyphenyl)-2-propen-1-ethanoate (2), 6,7,8-trimethoxy-2H-1-benzopyran-2-one (3), 3-(4-O-beta-D-glucopyranoside-3,5-dimethoxyphenyl)-2-propen-1-ol (6), 2-(3-hydroxy-4-methoxyphenyl)-3,5-dihydroxy-7-O-beta-D-glucopyranoside-4H-1-benzopyrane-4-one (7), reported for the first time from this species. Structures of these compounds were determined by spectral analysis. These compounds showed strong inhibitory activity against alpha-glucosidase.