M.M. Dhar

Aporphine alkaloids of annona squamosa

Abstract The aporphine alkaloids anonaine, roemerine, norcorydine, corydine, norisocorydine, isocorydine and glaucine have been isolated from Annona squamosa .

Naphthaquinones of Arnebia nobilis

Abstract Silica gel chromatography of the fraction from Arnebia nobilis possessing antibiotic and anticancer activities has yielded three new naphthaquinones, 5,8-dihydroxy-2-(1′-β,β-dimethylacryloxy-4′-methylpentyl)-1,4-naphthaquinone, 5,8-dihydroxy-2-(4′-hydroxy-4′-methylpentyl)-1,4-naphthaquinone and 2-(1′-acetoxy-4′-hydroxy-4′-methylpentyl)-5,8-dihydroxy-1,4-naphthaquinone, along with alkannin [5,8-dihydroxy-2-(1′-hydroxy-4′-methylpent-3′-enyl)-1,4-naphthaquinone], 5,8-dihydroxy-2-(1′-β,β-dimethylacryloxy-4′-methylpent-3′-enyl)-1,4-naphthaquinone and 2-(1′-acetoxy-4′-methylpent-3′-enyl)-5,8-dihydroxy-1,4-naphthaquinone, which were reported earlier.

The aporphine alkaloids of Litsea glutenosa

Abstract The aporphine alkaloids, norboldine, boldine, laurotetanine, N-methyllaurotetanine, actinodaphnine and N-methylactinodaphnine have been isolated from Litsea glutenosa var. glabraria Hook.

The alkaloids of croton sparsiflorus

Abstract Three proaporphine bases provisionally designated crotsparine (I), m.p. 193–194°, N -methyl-crotsparine (III), m.p. 223–225°, and N,O -dimethylcrotsparine (IV), m.p. 125–127°; two dihydroproaporphines, crotsparinine (II), m.p. 184–185°, and N -methylcrotsparinine (V), m.p. 160–161°, and the known aporphine alkaloid, sparsiflorine (X), m.p. 229–231°, have been isolated from Croton sparsiflorus Morong and their structures and stereochemistry assigned. N -Methylcrotsparine is of biological interest as a hypotensive agent.

Hedychenone: A furanoid diterpene from Hedychium spicatum☆

Abstract The structure of hedychenone, a furanoid diterpene, isolated from the rhizomes of Hedychium spicatum has been deduced on the basis of spectroscopic and chemical evidence.

Immunomodulation by opioid peptidomimetic compound

Objective: As a follow-up to our earlier studies on immunomodulation with opioid peptides, we synthesized and evaluated immunomodulatory activity of four peptidomimetic compounds, i.e. Tyr-NH-C(Me)2-CH2-O-Phe-NH2 (1), Tyr-NH-C6H5-(o)-CH2-CH2-O-Phe-NH2 (2), Tyr-NH-CH2-CH2-O-Phe-NH2 (3) and Tyr-NH-CH(D-Et)-CH2-O-Phe-NH2 (4). Methods: These compounds were synthesized in solution phase and evaluated for their immunomodulatory properties in vitro by mixed lymphocyte reaction (MLR), proliferation of opioid receptor-expressing cells, production of tumor necrosis factor-α (TNF-α) and nitric oxide. Results: This study shows the immunosuppressive potential of synthetic peptidomimetic compound 3. This compound inhibited two-way MLR and suppressed the proliferation of the µ-opioid receptor expressing human embryonic kidney cells HEK 293 in vitro. Inhibition of MLR by compound 3 was reversed by naloxone (opioid receptor antagonist) and β-funaltrexamine hydrochloride (µ-opioid receptor antagonist). The immunosuppressive effect of compound 3 was further demonstrated by inhibition of TNF-α and nitric oxide production in lipopolysaccharide-stimulated human PBMCs and mouse macrophage cells RAW 264.7, respectively. Conclusion: These observations suggest that compound 3 inhibits MLR through µ-opioid receptor present on cells.

Ipolearoside: A new glycoside from Ipomoea leari with anti-cancer activity☆

Abstract Ipolearoside, a new glycoside with anticancer activity, has been isolated from Ipomoea leari Paxt. On acid hydrolysis in methanol, it gave the aglycone methyl ester, characterised as methyl 3,11-dihydroxyhexadecanoate. Ipolearoside is a complex glycoside of 3,11-dihydroxyhexadecanoic acid and glucose, rhamnose and fucose.

Aporphine alkaloids of Litsea sebifera, L. wightiana and Actinodaphne obovata

Abstract Boldine, laurotetanine, N -methyllaurotetanine, and actinodaphnine from Litsea sebifera pers., boldine and norboldine from L. wightiana Hook. f. and laurotetanine, N - methyllaurotetanine and actinodaphnine from Actinodaphne obovata Bl. have been isolated.

Two new sterols from Physalis franchetii fruit

Abstract Two new steroids physanol A, 3β-benzoyloxy-6-oxo-stigmast-7,20-diene-11α-ol and physanol B, 3β-benzoyloxy-6-oxo-stigmast-7-ene-11α-ol have been isolated from the fruit of Physalis franchetti.

Absolute configuration of crotsparine, crotsparinine and sparsiflorine☆

Abstract Absolute configurations of crotsparine, crotsparinine and sparsiflorine have been determined.