Bandi Siva

Methyl angolensate and mexicanolide-type limonoids from the seeds of Cipadessa baccifera.

Six new methyl angolensate type (1-6) and three new mexicanolide-type (7-9) limonoids, along with six known limonoids (10-15), were isolated from the seeds of Cipadessa baccifera. The structures of all these compounds were established by extensive 1D, 2D NMR, and HRESIMS experiments, and structures of 11 and 13 were further confirmed by a single crystal X-ray diffraction analysis, which are reported for the first time. The cytotoxic activities of these isolates were also studied against A549, MCF7, ME-180, HT-29, B-16, ACHN cancer cell lines using MTT assay, and results indicated that compounds 4, 10, and 14 displayed potent cytotoxic activity against B-16, ACHN cell lines with an IC50 values of 8.51 and 7.0 μg/mL, respectively.

Phytochemical investigation of sesquiterpenes from the fruits of Schisandra chinensis and their cytotoxic activity.

Phytochemical investigation of ethanolic extract from the fruits of Schisandra chinensis led to the isolation of four new sesquiterpenes (1-4); their structures were determined by a combination of NMR (1D and 2D) and MS spectroscopic techniques. In addition, all these isolates were screened for their cytotoxic activities against MCF-7, Caco-2, Hela, Lncap, Hep G2 and MDA-MB231 cancer cell lines. Results indicated that compounds 2 and 3 displayed potent cytotoxic activity against Caco2 cell lines with IC50 values of 17.10 μg/mM and 16.46 μg/mM, respectively.

Advanced glycation end-products inhibitors isolated from Schisandra grandiflora

Free radicals scavenging and advanced glycation end-products (AGEs) inhibitory potentials in crude chloroform extract of Schisandra grandiflora were evaluated. Bioassay-guided isolation of the chloroform extract led to the identification of 24 compounds. Among the isolates, ( ± ) gomisin M1, arisantetralone C and D, macelignan, saurulignan B and SZ-MO displayed potent-free radical scavenging as well as AGEs inhibitory potentials. This is the first report identifying the presence of AGEs inhibitory activity and assigning AGEs inhibitory activity to these compounds. Therefore, our research finds new application of traditional medicinal plant S. grandiflora having capacity to reduce formation and accumulation of AGEs in diabetes.

Minor Pyranonaphthoquinones from the Apothecia of the Lichen Ophioparma ventosa

Four new quinonoid naphthopyranones, ophioparmin (1), 4-methoxyhaemoventosins (2a and 2b), and 4-hydroxyhaemoventosin (3), together with anhydrofusarubin lactone (4) and haemoventosin (5) were isolated from the fruiting bodies of Ophioparma ventosa, a crustose lichen. Their structures were determined by spectroscopic analyses, and the absolute configurations of 1 and 2 were elucidated through experimental and calculated electronic circular dichroism analyses. Compounds 1, 2, and 5 exhibited moderate to strong antioxidant activities. The main pigment haemoventosin exhibited significant cytotoxicity toward a panel of nine cell lines.

New seco-limonoids from Cipadessa baccifera: Isolation, structure determination, synthesis and their antiproliferative activities.

A comprehensive reinvestigation of chemical constituents from CHCl3-soluble extract of Cipadessa baccifera led to the isolation of two new limonoids 1, 2 together with six known compounds 3-8. Their structures were established on the basis of extensive analysis of spectroscopic (IR, MS, 2D NMR) data. Further, a series of cipaferen G (3) derivatives were efficiently synthesized utilizing Yamaguchi esterification (2, 4, 6-trichlorobenzoyl chloride, Et3N, THF, DMAP, toluene) at the C-3 position of the limonoids core, which is being reported for the first time. The anti-proliferative activity of the isolates and the synthetic analogues were studied against HeLa, PANC 1, HepG2, SKNSH, MDA-MB-231 and IMR32 cancer cells using the sulphorodamine B assay. Among the tested compounds, 13d and 13h manifested potent activity against IMR32, HepG2 cell lines with GI50 0.013 and 0.01μM, respectively.

Cytotoxic sesquiterpenes from Hedychium spicatum: isolation, structure elucidation and structure-activity relationship studies.

Phytochemical investigation of chloroform extract from rhizomes of Hedychium spicatum resulted in the isolation of six new sesquiterpenes (1-6) along with fifteen known compounds (7-21). Their structures were elucidated on the basis of the extensive spectroscopic analyses (IR, Mass and NMR) and by comparison of the data with those reported in the literature. Further, cytotoxic activities of all the isolates were evaluated by determining their inhibitory effects against A-549, B-16, Hela, HT-29, NCI-H460, PC-3, IEC-6 and L-6 cancer cell lines. Results indicated that compounds 1 and 3 may serve as an important natural lead compounds for future development as they showed potent cytotoxic activity against Hela cell lines with an IC50 value of 0.3 μg/mL and 1.80 μg/mL, respectively.

Novel malyngamide structural analogs: synthesis and biological evaluation

In the course of our search for new anticancer agents, a series of novel malyngamide derivatives were synthesized by sharpless asymmetric epoxidation, followed by Julia-Kocinski olefination reactions as key reaction sequence. Anticancer activities of all these derivatives were screened against IMR-32, SF-295, SKNSH, HeLa, Colon-502713, SW-620, and Hop-62 cell lines for the first time.

New free radical scavenging neolignans from fruits of Piper attenuatum

Objective: The aim was to study and identify free radicals scavenging and antihyperglycemic principles in fruit of Piper attenuatum. Materials and Methods: Bioassay guided identification of extracts possessing potent free radical scavenging activity, and isolation of compounds was done. Chloroform extract of P. attenuatum possessing potent radical scavenging activity was also evaluated for antihyperglycemic activity following oral glucose tolerance test in rats. Results: Nine neolignans namely, denudatin B (1), iso-4’, 5’-dimethoxy-3, 4-methylenedioxy-2’-oxo-Δ3’,5’,8’-8.1’-lignan (2), lancifolin D (3), denudatin A (4), wallichinin (5), piperenone (6), lancifolin C (7), 2-oxo-piperol B (8), piperkadsin A (9) and a crotepoxide (10) was identified in Chloroform extract of P. attenuatum. Neolignans (1-9) displayed potent 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) radical and piperkadsin A (9) also displayed 1, 1-diphenyl-2-picrylhydrazyl radical scavenging activity. Analysis of structure-activity relationship revealed that presence of furan ring and methoxy groups is an important criterion to influence 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging potentials. Chloroform extract of P. attenuatum fruit could not display antihyperglycemic activity following oral glucose tolerance test in rats. Conclusion: Neolignans present in P. attenuatum fruits are potent free radical scavengers and this is the first report identifying these compounds and activities in this fruit.

Synthesis and biological evaluation of Schizandrin derivatives as potential anti-cancer agents

A new series of Schizandrin (1) derivatives were synthesized utilizing the C-9 position of the Schizandrin core and evaluated for their cytotoxic activities against HeLa (cervical cancer), A549 (lung cancer), MCF-7 (breast cancer) and DU-145 (prostate cancer) cell lines. Among the synthesized series, 4e, 4f, 4g and 5 showed potent activities against tested cell lines. More significantly, compound 5 exhibited most potent cytotoxic activity against DU-145 with an IC50 value of 1.38 μM which is comparable to the standard agent, doxorubicin. Further, flow cytometry analysis indicated that 5 arrested cells in G2/M phase and consequently leading to apoptosis. Molecular docking analysis showed that 5 occupied the colchicine binding pocket of tubulin. Overall, the present study demonstrates that 5, as a mitotic-agent.

Design, synthesis and anti-proliferative activities of novel 7′-O-substituted schisantherin A derivatives

A series of schisantherin A (1) derivatives were efficiently synthesized utilizing Yamaguchi esterification (2,4,6-trichlorobenzoyl chloride, Et3N, THF, DMAP, toluene) at the C-7′ position of the schisantherin A core. The synthesized derivatives were evaluated for their anti-cancer activities against SIHA, PANC 1, MDA-MB-231, IMR-32, DU-145 and A549 cancer cell lines using sulforhodamine B assay. Within the new series tested, compound 29 displayed the most promising cytotoxic effect against the human cervical cancer cell line (SIHA) with a GI50 value of <0.01 μM, which is comparable to that of the standard drug, doxorubicin. Mechanism of action studies validated that 29 functions as a microtubule inhibitor. Additionally, several of the other analogues exhibited potent activity against the tested cell lines. Based on the results obtained, structure–activity relationships (SARs) were established and a correlation between the activities was also observed and discussed.