Synthesis of some novel orsellinates and lecanoric acid related depsides as α-glucosidase inhibitors.

Sixteen novel orsellinic esters (6a-l, 7a-d) along with four lecanoric acid related depsides (3a-c, 4) were synthesized and confirmed their structures by spectroscopic data (1H, 13C & HRMS). The synthesized compounds were evaluated for their in vitro α-glucosidase (Saccharomyces cerevisiae) inhibitory potential. Among the tested compounds, 3c (IC50: 140.9 µM) and 6c (IC50: 203.9 µM) displayed potent α-glucosidase inhibitory activity and found more active than the standard drug acarbose (IC50: 686.6 µM). Both the test compounds were subjected to in vivo antihyperglycemic activity using sucrose loaded model in Wistar rats and found compound 3c exhibited significant reduction in glucose levels.

Design, synthesis, anti-inflammatory, cytotoxic and cell based studies of some novel side chain analogues of myrrhanones A & B isolated from the gum resin of Commiphora mukul.

Myrrhanones A (1) and B (2), isolated from the gum resin of Commiphora mukul, were reported to exhibit anticancer and anti-inflammatory activities. In view of their interesting skeletal features and biological activities they have been chemically modified by exploiting their side chain functionalities to synthesise 29 diverse analogues. All the synthesized analogues were screened for their cytotoxic potential against a panel of five human cancer cell lines which include DU145 (Prostate), HT-29 (Colon), MCF-7 (Breast), Hela (Cervical) and U87MG (Glioblastoma) along with a normal cell line (L132). The synthesized analogues were also screened for anti-inflammatory activity against TNF-α and IL-1ß using LPS induced inflammation model employing U937 cells. The biological screening results revealed that compounds 4b (piperidine analogue), 9d (linear aliphatic four member amide analogue) and 9i (N-methyl piperazine analogue) displayed significant cytotoxic activity against MCF-7, HT-29 and DU145 [IC50 (µM): 4.65 ±â€¯1.28, 5.48 ±â€¯0.13 and 6.63 ±â€¯1.39] respectively. These analogues were further taken up for apoptotic assay, which confirmed that compounds 4b, 9d and 9i induced apoptosis in MCF-7, HT-29, DU145 cells and arrested in G0/G1 phase. Further, compounds 9c and 9g found to exhibit good anti-inflammatory activity against TNF-α with IC50 (µM) values of 10.02 ±â€¯2.13 and 10.53 ±â€¯0.48 respectively, while compound 2 exhibited strong inhibitory activity against both TNF-α (IC50: 9.39 ±â€¯0.44 µM) and IL-1ß (IC50: 12.15 ±â€¯1.36 µM).

Novel menadione hybrids: Synthesis, anticancer activity, and cell-based studies.

A series of novel menadione-based triazole hybrids were designed and synthesized by employing copper-catalyzed azide-alkyne cycloaddition (CuAAC). All the synthesized hybrids were characterized by their spectral data (1 H NMR, 13 C NMR, IR, and HRMS). The synthesized compounds were evaluated for their anticancer activity against five selected cancer cell lines including lung (A549), prostate (DU-145), cervical (Hela), breast (MCF-7), and mouse melanoma (B-16) using MTT assay. The screening results showed that majority of the synthesized compounds displayed significant anticancer activity. Among the tested compounds, the triazoles 5 and 6 exhibited potent activity against all cell lines. In particular, compound 6 showed higher potency than the standard tamoxifen and parent menadione against MCF-7 cell line. Flow cytometric analysis revealed that compound 6 arrested cell cycle at G0/G1 phase and induced apoptotic cell death which was further confirmed by Hoechst staining, measurement of mitochondrial membrane potential (ΔΨm) and Annexin-V-FITC assay. Thus, compound 6 can be considered as lead molecule for further development as potent anticancer therapeutic agent.

Novel triazole hybrids of myrrhanone C, a natural polypodane triterpene: Synthesis, cytotoxic activity and cell based studies.

The 3-keto functionality in ring A of myrrhanone C, a natural bicyclic triterpene has been chemically modified and synthesized 27 novel triazole hybrids belonging to two different series in very good to excellent yields (66-83%). The synthesized compounds were thoroughly characterized by their spectroscopic data (IR, (1)H&(13)C NMR, HRMS). All the synthesized compounds were evaluated for their cytotoxic potential against a panel of five human cancer cell lines by employing MTT assay using doxorubicin as the standard. In general the synthesized compounds showed anticancer activity against almost all the cell lines screened. Interestingly, the oxime based triazoles (4a-4n) showed higher activity than the benzylidene triazoles (6a-6m). Most significantly compound 4a showed potent activity against all the tested cell lines, especially against lung cancer (A-549) with an IC 50 of 6.16 µm. In view of their significant activity against lung cancer cell lines, compounds 4a and 4l were subjected to detailed biological studies, which revealed that they arrested cell cycle in G2/M phase and induced cell death by apoptosis that was further confirmed by Hoechst staining, measurement of mitochondrial membrane potential (ΔΨm) and Annexin V-FITC assay. These compounds will serve as lead molecules in the development of potent anticancer drug candidates especially for lung cancer.

Synthesis and anticancer activity of novel fused pyrimidine hybrids of myrrhanone C, a bicyclic triterpene of Commiphora mukul gum resin.

Myrrhanone C [8(R)-3-oxo-8-hydroxypolypoda-13E,17E,21-triene], a bicyclic triterpene isolated from the gum resin of Commiphora mukul, has been chemically transformed to synthesize a series of ten novel pyrimidine hybrids in good to excellent yields. The synthesized compounds (2-22) were evaluated for their anticancer potential against a panel of six cancer cell lines, namely A-549 (lung), Hela (cervical), MCF-7 (breast), ACHN (renal), Colo-205 (colon) and B-16 (mouse melanoma) by employing the MTT assay. In general, the synthesized compounds showed significant anticancer activity against all the cancer cell lines tested. Interestingly, the pyrimidine hybrids 18 and 19 showed good activity against the A-549, MCF-7, B-16, Colo-205 and ACHN cancer cell lines with [Formula: see text] values between 7.7-37.8 [Formula: see text]M. Most significantly, compounds 19 (IC[Formula: see text]: 7.7 [Formula: see text]M) and 18 (IC[Formula: see text]: 9.5 [Formula: see text]M) showed about five- and six-fold enhanced activities, respectively, compared to the parent myrrhanone C (1) against A-549 cell line. Flow cytometric analysis revealed that compounds 18 and 19 induced apoptosis in A-549 cells and arrested the cell growth in the G0/G1 phase.

Quantitative estimation of (-)-hinokinin, a trypanosomicidal marker in Piper cubeba, and some of its commercial formulations using HPLC-PDA.

The fruits of Piper cubeba have been used in Ayurvedic system of medicine for pain, tastelessness, painful urination and mouth diseases. Among its various chemical constituents, (-)-hinokinin, a trypanosomicidal dibenzylbutyrolactone lignan, is found in significant quantities. For quality evaluation of P. cubeba fruit and its commercial formulations, there is an urgent need to develop an analytical method based on (-)-hinokinin. For this purpose, an HPLC method was developed using photo diode array detector and Waters HR C18 column with gradient elution consisting of water and acetonitrile. The developed method was validated as per ICH-Q2B guidelines and found to be accurate, precise and linear over a wide range of concentrations (5-300 µg/mL). (-)-Hinokinin contents were found to be in the range of 0.005-0.109% (m/m) in various P. cubeba samples. The developed method was extended to LC-MS for further identification and characterization of (-)-hinokinin in samples. The developed method is simple, rapid and specific, and can be used as a tool for quality control of P. cubeba fruits and its commercial formulations.

Synthesis and anticancer activity of some novel 5,6-fused hybrids of juglone based 1,4-naphthoquinones.

Six novel 5,6-fused hybrids such as dihydrobenzofuran-quinone (4a and 4b), benzofuran-quinone (5a and 5b) and chromene-quinone (6a and 6b) of juglone based 1,4-naphthoquinones were synthesized by employing a three step protocol with the cyclisation of o-allyl phenol as the key step. The anticancer activity of the newly synthesized compounds was evaluated in vitro against seven human cancer cell lines including cervix (ME-180 and HeLa), breast (MCF-7, MDA-MB-453 and MDA-MB-231), prostate (PC-3) and colon (HT-29) by using MTT assay. The screening results showed that majority of the synthesized compounds exhibited significant anticancer activity. In particular, compounds 6a and 6b showed potent activities than the standard drug etoposide against prostate and breast cancer cell lines respectively. Flow cytometric analysis revealed that compounds 6a and 6b induced apoptosis and arrested the cell cycle at G2/M phase in PC-3 and MDA-MB-453 cells respectively.

Synthesis of novel ring-A fused hybrids of oleanolic acid with capabilities to arrest cell cycle and induce apoptosis in breast cancer cells.

Six novel oleanolic acid ring-A fused hybrids (5-10) have been synthesized by employing a four step protocol with the introduction of benzylidene functionality at C-2 as the key step. Their structures were established by high resolution NMR and Mass spectral data. The synthesized compounds have been screened against seven human cancer cell lines including ME-180 & HeLa (cervix), MCF-7, MDA-MB-453 & MDA-MB-231 (breast), PC-3 (prostate) and HT-29 (colon) using MTT assay. Most significantly, compound 10 showed potent activity against the three breast cancer cell lines. The IC50 value (10.60 µM) of compound 10 against MCF-7 found to be much lower than that of the standards and parent compound. Flow cytometric analysis reveals that compound 10 arrests cell cycle in S phase and induces apoptosis in MCF cells.

A rapid and highly sensitive UPLC-QTOF MS method for quantitative evaluation of Nardostachys jatamansi using Nardin as the marker.

Nardostachys jatamansi DC. is a highly reputed Medhya and Nootropic (Learning and Memory) Ayurvedic medicinal plant. Its use as herbal medicine singly and as an ingredient of multi-herbal formulations is fast increasing. In order to authenticate and evaluate it quantitatively, its standardization is highly warranted with respect to a reliable marker. In this connection a rapid and highly sensitive UPLC-QTOF MS method has been developed. The analysis was carried out on an Acquity BEH C(18) column with gradient elution of methanol-water and 3 mm ammonium acetate using QTOF mass detector in negative ionization mode. The method was validated over a concentration range of 9.76-156.25 ng/mL nardin. The calibration curve is linear with the correlation coefficient (r) and coefficient of determination (R(2)) were 0.9997 and 0.9995 respectively. The LOD and LOQ were 3.050 and 9.277 ng/mL respectively. The recovery of nardin in the range 96.36-111.13% achieved from spiked samples was consistent and reproducible. The inter-day and intra-day assay precision of the analytes over the entire concentration range was less than 5%. The developed method required only 4 min for chromatography to authenticate and quantify the marker, viz. nardin in N. jatamansi samples, in addition to the sample preparation time.

Three new pentacyclic triterpenes and some flavonoids from the fruits of an Indian Ayurvedic plant Dendrophthoe falcata and their estrogen receptor binding activity.

Extensive chromatographic screening of extracts of the fruits of the Indian Ayurvedic plant, Dendrophthoe falcata, resulted in the isolation of three new triterpenes, 3beta-acetoxy-1beta-(2-hydroxy-2-propoxy)-11alpha-hydroxy-olean-12-ene (1), 3beta-acetoxy-11alpha-ethoxy-1beta-hydroxy-olean-12-ene (2) and 3beta-acetoxy-1beta-hydroxy-11alpha-methoxy-olean-12-ene (3) along with nine known compounds, 3beta-acetoxy-1beta,11alpha-dihydroxy-olean-12-ene (4), 3beta-acetoxy-1beta,11alpha-dihydroxy-urs-12-ene (5), 3beta-acetoxy-urs-12-ene-11-one (6), 3beta-acetoxy-lup-20(29)-ene (7), 30-nor-lup-3beta-acetoxy-20-one (8), (20S)-3beta-acetoxy-lupan-29-oic acid (9), kaempferol-3-O-alpha-L-rhamnopyranoside (10), quercetin-3-O-alpha-L-rhamnopyranoside (11), and gallic acid (12). The structures of these compounds were determined using 1D and 2D NMR and high resolution electrospray mass spectrometry. These compounds were assayed for binding to estrogen receptors-alpha and beta and kaempferol-3-O-alpha-L-rhamnopyranoside (10) was found to be a ligand for both receptors with greater affinity for beta. The triterpenes (1-9) are reported for the first time in the genus Dendrophthoe and assumes taxonomic significance.

Antimicrobial activity of some pentacyclic triterpenes and their synthesized 3-O-lipophilic chains.

The major metabolites of Diopsyros melanoxylon viz. amyrins and ursolic acid and their lipophilic 3-O-fatty acid ester chains (C12-C18), which are synthesized now under mild esterification conditions in excellent yields (80-95%), were evaluated for their antimicrobial activity against a series of Gram positive and Gram negative bacteria. Significantly these compounds were found to exhibit potent activity against Gram negative bacteria Pseudomonas syringae (ATCC #13457) and fairly good activity against Gram positive bacteria, Bacillus sphaericus (ATCC #14577) and Bacillus subtilis (ATCC #6051).