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The efficient synthesis of novel 2,2-dimethyl-chroman-6-yl pentadienoic acid amides (7a-e) as synthetic piperine analogs has been established by the condensation of 5-(2,2-dimethyl-chroman-6-yl)-4-methyl-penta-2,4-dienoic acid 6 with various aromatic amines. All the synthesized piperine analogs were bioevaluated for their potential as inhibitors of multidrug efflux pump NorA overexpressing Staphylococcus aureus SA 1199B. Out of all the prepared analogs, 5-(2,2-dimethyl-chroman-6-yl)-4-methyl-penta-2,4-dienoic acid ethyl ester 5 and 5-(2,2-Dimethyl-chroman-6-yl)-4-methyl-2E,4E-pentadienoic acid pyrrolidide 7d were found promising. The active compounds were also evaluated for their synergistic effect with ciprofloxacin, whose results substantially increase the activity of ciprofloxacin against both Nora overexpressing and wild type Staphylococcus aureus isolates. Structures of the synthesized compounds have been elucidated on the basis of spectral data (IR, 1H NMR and Mass analysis).

Cancer is possibly one of the most devastating and complex disease and therefore involves chemotherapy as one of the frontline strategies in its therapy. However, expected toxicity and resistance with chemotherapeutic agents encourage us to use the plant derived natural chemotherapeutic sources at the clinical stage of cancer therapy. In view of this strategy, herein new glycosides and isoflavonoids were isolated from Iris kashmiriana Baker and subjected to structure elucidation followed by their biological evaluation. Isolated compounds and their derivatives were purified by the column chromatography and structural identification was made by a combination of various spectroscopic technique vis. UV, IR, 1H NMR, 13C NMR, DEPT, 2-D NMR and mass spectrometry coupled with chemical analysis. Furthermore, an in silico library of isolated isoflavones and its analogues were designed. NF-kappaB (transcription factor that facilitates angiogenesis, inflammation, invasion and metastasis) was selected as a target to evaluate the anticancer and antioxidant activity of isoflavones and its analogues. Designed library of isoflavones and analogues were docked into the active site of NF-kappa B and the most active 15 analogues were selected for synthesis. Finally, all compounds were evaluated for their cytotoxicity against various cell lines and antioxidant activity with different methods that demonstrate their anti-cancer and anti-oxidant potential. The cell cycle specificity of the cytotoxicity was further analyzed by corresponding analysis, using flow cytometer. Most of the compounds exhibit moderate activity, whereas the 5,7,8-trihydroxy-3-(4-methoxyphenyl)-4H-chromen-4-one, 5,7,8-trihydroxy-3-(4-hydroxyphenyl)-4H-chromen-4-one, 5,7,8-triacetoxyoxy-3-(4-methoxyphenyl)-4H-chromen-4-one and 6,7-diacetoxyoxy-3-(4-methoxyphenyl)-4H-chromen-4-one showed distinct broad-spectrum anticancer activity with IC50 values ranges between 3.8 and 5.6 μg/mL. Cell cycle analysis indicates that these compounds induced cell cycle arrest at G2/M phase.

Three new triterpenoids, designated as koelpinin-A, B and C and characterised as 28-nor-lup-12,17-dien-3 beta,16 alpha-diol,3 beta-acetoxy-28-nor-lup-12,17-dien-16 alpha-ol and 28-nor-lup-12,17-dien-3 beta-ol-16-one, respectively, together with 30-nor-lup-3 beta-ol-20-one, taraxeryl acetate and germanicol, were isolated, from the aerial parts of Koelpinia linearis. 13C-NMR shifts were assigned after performing APT and DEPT experiments.

From the rhizomes of the Iris kashmiriana , two new isoflavones, isocladrastin and kashmigenin, were characterized as 3′-hydroxy-6,7-4′-trimethoxy-isoflavone and 4′-hydroxy-3′,5′-dimethoxy-6,7-methylenedioxy-isoflavone, respectively. Also, junipegenin-B has been found present in this plant species.

Three new triterpenoids, designated as koelpinin - A, B and C and characterised as 28-nor-lup-12,17-dien-3β,16α-diol,3β-acetoxy-28-nor-lup-12,17-dien-16α-ol and 28-nor-lup-12,17-dien-3β-ol-16-one, respectively, together with 30-nor-lup-3β-ol-20-one, taraxeryl acetate and germanicol, were isolated, from the aerial parts of Koelpinia linearis. 13 C -NMR shifts were assigned after performing APT and DEPT experiments.

From the rhizomes of the Iris kashmiriana , two new isoflavones, isocladrastin and kashmigenin, were characterized as 3′-hydroxy-6,7-4′-trimethoxy-isoflavone and 4′-hydroxy-3′,5′-dimethoxy-6,7-methylenedioxy-isoflavone, respectively. Also, junipegenin-B has been found present in this plant species.

On the basis of single crystal X-ray crystallography the structure of magnosalin now isolated from Piper clusii has been revised to 1β,2α,3β

Two new nortriterpenes have been isolated from Phlomis spectabilis and characterised as 28-noroleana-16,21-diene-3α,19α,23,29-tetrol and 28-noroleana-16,21-diene-3α,19α,29-triol-23-al.

3′-Hydroxy- and 4′-hydroxy-5,5′-dimethoxy-6,7-methylene-dioxyisoflavones were identified in the rhizomes of Iris kashmiriana .

Recently Dhar et al. reported the isolation of two new steroidal lactones from the leaves of Datura quercifolia HBK and formulated them as 5α,12α,17α-trihydroxy-1-oxo-6α, 7α-epoxy-22 S -witha-2,24-dienolide and 5α,17α-dihydroxy-1, 12-dioxo-6α,7α-epoxy-22 S -witha-2,24-dienolide on the basis of UV, IR, NMR and MS studies. Further detailed chemical and spectral studies have led to revised structures, namely 5α, 12α-dihydroxy-1-oxo-6α,7α: 24α, 25α-diepoxy-20 S , 22 R -with-2-enolide and 5α-hydroxy-1, 12-dioxo-6α, 7α: 24α, 25α-diepoxy-20 S , 22 R -with-2-enolide, respectively, for the above two compounds.

From the petrol extract of Swertia petiolata a new natural triterpene, 3β-hydroxylup-13(18)-ene has been isolated in addition to 3β-hydroxylup-12en-28-oic acid and ursolic acid.

A novel withanolide, 5α,12β-dihydroxy-1-oxo-6α,7α-epoxy-(22 R )-witha-2,24 dienolide was isolated from a benzene extract of fresh leaves of Datura quercifolia . The structure was established by chemical and spectroscopic methods.

Two novel isomeric hopene triterpenes, Swertialactone C and Swertialactone D have been isolated from Swertia petiolata. Their structures were established as 2,3-seco-2 → 3 lactone, 1β,3β-epoxy-hop-17(21)-ene and 2,3-seco-2 → 3 lactone, 1β,3β-epoxy-hop-16-ene, respectively.

Coscinium fenestratum furnished a new minor alkaloid, 12,13-dihydro-8-oxo-berberine, [5,6,13,13a-tetrahydro-9,10-dimethoxydibenzo( a , g )1,3-benzodioxolo(5,6a)quinalizine-8-one], as well as berberine, oxyberberine, tetrahydroberberine (canadine), sitosterol and stigmasterol.

Analysis of a petrol extract of the leaves of Piper peepuloides resulted in the isolation of a new cinnamoyl pyrrolidine amide characterized as Z-pyrrolidine-1-3-(6-methoxy-1,3-benzodioxol-5-yl)-1-oxo-2-propenyl along with peepuloidin, 2-methoxy-4,5-methylenedioxy-Z-cinnamoyl piperidide, β-sitosterol and β-sitosterol glucoside.