Urease and Carbonic Anhydrase Inhibitory Effect of Xanthones from Aspergillus nidulans, an Endophytic Fungus of Nyctanthes arbor-tristis.

Urease plays a major role in the pathogenesis of peptic and gastric ulcer and also causes acute pyelonephritis and development of infection-induced reactive arthritis. Carbonic anhydrases (CA) cause pathological disorders such as epilepsy (CA I), glaucoma, gastritis, renal, pancreatic carcinomas, and malignant brain tumors (CA II). Although various synthetic urease and carbonic anhydrase inhibitors are known, these have many side effects. Hence, present studies were undertaken on ethyl acetate extract of Aspergillus nidulans, an endophytic fungus separated from the leaves of Nyctanthes arbor-tristis Linn. and led to the isolation of five furanoxanthones, sterigmatin (1: ), sterigmatocystin (3: ), dihydrosterigmatocystin (4: ), oxisterigmatocystin C (5: ), acyl-hemiacetal sterigmatocystin (6: ), and a pyranoxanthone (2: ). Acetylation of 3: gave compound O-acetyl sterigmatocystin (7: ). Their chemical structures were elucidated by 1H and 13C NMR and MS. The inhibitory effect of isolated compounds was evaluated on urease and carbonic anhydrase (bCA II) enzymes in vitro. Compounds 3: and 6: showed significant urease inhibition (IC50 19 and 21 µM), while other compounds exhibited varying degrees of urease inhibition (IC50 33 - 51 µM). Compounds 4, 6: and 7: exhibited significant inhibition of bCA II (IC50 values 21, 25 and 18 µM respectively), compounds 1: -3: displayed moderate inhibition (IC50 61, 76 and 31 µM respectively) while 5: showed no inhibition. A mechanistic study of the most active urease inhibitors was also performed using enzyme kinetics and molecular docking. All compounds were found non-toxic on the NIH-3T3 cell line.

Novel ursane-type triterpene from the fresh leaves of Carissa carandas and evaluation of cytotoxicity.

One novel ursolic acid derivative sabiracin 1 (11,25-epoxy-3ß-hydroxy-urs-12-en-28-oic acid) was isolated from the leaves of Carissa carandas, together with five known compounds para hydroxy benzaldehyde (2), ursolic acid (3), carissin (4), 22α-hydroxyursolic acid (5) and ß-sitosterol-3-O-ß-D-glucopyranoside (6). Compounds 2 and 5 were isolated for the first time from this genus. Structure elucidation was done by the help of spectroscopic techniques. Compounds 1-3, 5 and 6 were examined against oral cancer (CAL-27) and lung cancer (NCI-H460) cell lines. 6 showed good activity against oral cancer (IC50 18.69 µM), moderate activity against lung cancer (IC50 63.34 µM) and no cytotoxicity against normal cell lines.

Volatile constituents and in vitro activity of Syzygium aromaticum flower buds (clove) against human cancer cell lines.

The methanolic extract (SA-EXT) of Syzygium aromaticum flower buds and its fractions tested against three human cancer cell lines viz uterine cervix (HeLa), breast (MCF-7) and lung NCI (H-460) using sulforhodamine-B assay. The ethyl acetate soluble sub fraction (SA-EAS) was active only against HeLa cells with GI50value of 36± 3.4µg/mL. The most active sub-fraction (SA-PES-Fr-2) showed growth inhibition (GI50: 36, 50 and 68µg/ml against MCF-7, HeLa and NCI-H-460 cancer cell lines, respectively) with cytotoxic effect LC50= 88 ± 3.4 µg/mL against HeLa and LC50=86 ± 2.8 µg/mL against MCF-7. The most active sub-fraction (SA-PES-Fr-2) analyzed by GC and GC-MS techniques revealed that eugenol was most abundant (85.34%) along with minor constituents. Thus it can be concluded that growth inhibitory and cytotoxic effect residing in Syzygium aromaticum flower buds (clove) is more likely due to eugenol.

Triterpenoids from the aerial parts of Lantana camara.

Two new pentacyclic triterpenoids lancamarinic acid and lancamarinin have been obtained from the aerial parts of Lantana camara Linn. They were characterized as 22ß-acetoxy-3,25-epoxy-3α-hydroxyolean-12-en-28-oic acid and methyl 3,25-epoxy-3α-hydroxy-11-oxo-22ß-senecioyloxyolean-12-en-28-oate, respectively, through chemical transformation and exhaustive spectroscopic studies.

A natural flavonoid lawsonaringenin induces cell cycle arrest and apoptosis in HT-29 colorectal cancer cells by targeting multiple signalling pathways.

Colorectal cancer is the third most common malignancy in the world having a high mortality rate. Flavonoids possess many biological activities including anti-cancer activity. lawsonaringenin (LSG) is a flavonoid isolated from leaves of Lawsonia alba Lam. The objective of this study was to demonstrate the anti-cancer potential of LSG in colorectal cancer for the first time. The HT-29 cells were treated with LSG or 5-fluoruracil, as a positive control, to determine its effect on cell cytotoxicity by a MTT cell proliferation assay, and cell cycle progression and apoptosis using flowcytometry. We also determined the mechanisms underlying LSG-mediated growth inhibition of HT-29 cells by by investigating the expression of key oncogenes and apoptosis genes using q-RT PCR and immunocytochemical analysis. The cell cytotoxicity data showed that the IC50 value of LSG was significantly less than the IC50 value of 5-FU (50 µM). The anti-proliferative effect of LSG was mediated by arresting cells in the S phase of the cell cycle which then led to the induction of apoptosis the q-RT PCR and immunocytochemical analysis showed that LSG reduced the expression of ß-catenin (non-phosphorylated) and its downstream signalling target c-Myc, whereas it increased the phosphorylation of ß-catenin. Furthermore, LSG also downregulated the expression of oncogene K-Ras and anti-apoptotic proteins, Bcl-2, and Bcl-xL. In conclusion, our data demonstrates that LSG exerted its anti-tumor activity by arresting the cell cycle in S phase, and by downregulating the expression of oncogenes including ß-catenin, c-Myc, K-Ras and anti-apoptosis proteins Bcl-2 and Bcl-xL. This study suggests a potential use of natural flavonoid, lawsonaringenin, to attenuate colorectal cancer growth; however, further pre-clinical/clinical studies are required to establish its role as a therapeutic agent.

Attenuation of palmitate induced insulin resistance in muscle cells by harmala, clove and river red gum.

The present study aimed to decipher the mechanism of action of selected anti-diabetic plants extracts on palmitic acid mediated insulin resistance in muscle cells. Our results showed that extract from Peganum harmala seeds, Eucalyptus camaldulensis and Syzygium aromaticum leaves, showed significant antioxidant activity. We found that these extracts were able to affect stress signalling by reducing p-38 MAP kinase phosphorylation. They also reduced phosphorylation of substrate for insulin receptor (IRS) at serine residues and increased its phosphorylation at tyrosine residues and also enhanced PKB phosphorylation. Glucose uptake was also enhanced in muscle cells after treatment with these extracts. Extracts from Lantana camara, Psidium gujava fruit and different parts of Cassia alata did not affect FFA mediated down-regulation of insulin signalling. The study conclude that seeds of Peganum harmala and leaves of Eucalyptus camaldulensis and Syzygium aromaticum enhanced insulin signal transduction and glucose uptake in muscle cells via reducing oxidative stress. As a result, these herbal extracts may be considered useful to protect from insulin resistance.

Nematicidal triterpenoids from Lantana camara.

A new triterpene, lancamarolide (1), and seven known triterpenes, oleanonic acid (2), lantadene A (3), 11α-hydroxy-3-oxours-12-en-28-oic acid (4), betulinic acid (5), lantadene B (6), and lantaninilic acid (7) were isolated from the aerial parts of Lantana camara in the course of bioassay-guided isolation, and their nematicidal activities against Meloidogyne incognita, the root knot nematode, were carried out. Oleanonic acid was found to be the most active compound and exhibited 80% mortality after 72 h at 0.0625% concentration, which is comparable with that of the standard furadan.

Leishmanicidal Triterpenes from Lantana camara.

Two new natural triterpenes, lantaninilic acid and lantoic acid, along with the known triterpenes lantadene A, and oleanolic, ursolic, betulinic, lantanolic, and camaric acid, were obtained from the aerial parts of Lantana camara through bioassay-guided isolation, monitoring the in vitro antileishmanial activity against promastigotes of Leishmania major. Oleanolic acid (3), ursolic acid (4), lantadene A (5), and lantanilic acid (7) showed significant leishmanicidal activities with IC50 values of 53.0, 12.4, 20.4, and 21.3 µM, respectively. The IC50 value of ursolic acid (4; 12.4 µM) was found to be comparable with that of the standard drugs, pentamidine (IC50 15.0 µM) and amphotericin B (IC50 0.31 µM). The in vitro activities of L. camara and its constituents against promastigotes of Leishmania major are reported here for the first time.

Urease and human glioblastoma (U87) cells growth inhibitory iridoid glycoside acetates from Nyctanthes arbor-tristis Linn.

The present study was undertaken on the chemical constituents of ethanol extract of aerial parts of Nyctanthes arbor-tristis Linn., and their determination of growth inhibitory activity against glioblastoma multiforme cell line (U87) and urease inhibitory activity. Six constituents were isolated including two new arbortristoside F tetraacetate (1) and arbortristoside G heptaacetate (2) and four known arborside A tetraacetate (3), arborside C pentaacetate (4), 6,7-di-O-acetyl-6ß-hydroxyloganin hexaacetate (5) and nyctanthoside heptaacetate (6) iridoid glycoside acetates. Their structures were elucidated using spectroscopic methods, including 1D and 2D NMR and mass analyses. Compounds 3 and 6 showed significant growth inhibition of U87 cell line (76.41 and 87.62% inhibition) respectively while 2, 4 and 5 showed moderate inhibition. 3 and 6 showed notable urease inhibition (IC50 = 17.2 ± 0.4 and 17.2 ± 0.7 µM) respectively, and IC50 of 2, 4 and 5 were 23.8 - 56.3 µM. Compound 1 was inactive.

Anti-inflammatory and urease inhibitory iridoid glycosides from Nyctanthes arbor-tristis Linn.

ETHNOPHARMACOLOGICAL RELEVANCE: Nyctanthes arbor-tristis Linn. has been used by Ayruvedic physicians for the cure of different diseases including ulcers, gastric and inflammatory diseases. AIM OF THE STUDY: To isolate and identify compounds from this source and investigate their therapeutic potential for the treatment of gastric ulcer and related disorders. MATERIAL AND METHODS: The ethanol extract of fresh aerial parts of N. arbor-tristis was used in the present studies which was subjected to a bio-assay guided fractionation followed by chromatographic separations. The structures of pure compounds were elucidated using various spectroscopic techniques. The inhibition of urease enzyme was evaluated by weatherburn indophenol method. Molecular docking studies were determined by using Molecular Operating Environment (MOE) version 2020.0901 version. The intracellular ROS production from phagocytes was determined by chemiluminescence assay and NO generation was detected by Griess method. The proinflammatory cytokine TNF-α was quantified by ELISA. Cytotoxic activity was assessed by MTT assay. RESULTS: One previously undescribed iridoid glycoside arborside F (1) and four known iridoid glycosides arborside A (2), arborside C (3), loganin (4) and 7-O-trans-cinnamoyl-6ß-hydroxyloganin (5) were isolated and characterized in the present studies and their urease inhibitory activity was determined. Among these, 2 and 5 showed strong urease inhibition (IC50 = 12.1 ± 1.74 and 14.1 ± 0.59 µM respectively) (standard acetohydroxamic acid IC50 = 20.3 ± 0.42 µM), whereas rest of compounds showed moderate to low inhibition. Kinetic studies revealed that compounds 2 and 5 possess competitive type of inhibition. Molecular docking showed polar and non-polar interactions of compounds 2 and 5 with urease enzyme residues. Compounds 2 and 3 showed inhibition of ROS from whole blood (IC50 = 1.6 ± 0.3 and 2.5 ± 0.09 µg/mL respectively) and PMNs (IC50 = 1.5 ± 0.03 and 1.4 ± 0.0 µg/mL respectively). Compound 2 significantly inhibited nitric oxide and proinflammatory cytokine TNF-α (IC50 = 18.2 ± 3.0 and 73.8 ± 6.6 µg/mL respectively). Compounds 1, 4 and 5 were inactive on ROS. All isolated compounds were non-toxic on normal mouse fibroblasts (NIH-3T3) cells. CONCLUSIONS: The ethno pharmacological repute of N. arbor-tristis in treating gastric and anti-inflammatory ailments is supported by present studies which resulted in isolation of a potent urease inhibitory and anti-inflammatory agent arborside A (2) a potential anti-ulcer and anti-inflammatory drug lead.

An efficient synthesis of O- and N- alkyl derivatives of 4-aminobenzoic acid and evaluation of their anticancer properties.

A series of twenty alkyl derivatives (2-21) of 4-amino benzoic acid (1, PABA) have been prepared using potassium carbonate and opportune alkylating agents under simple and mild reaction conditions. Compounds (16-21) are reported for the first time. Electron impact mass spectrometry (EIMS), Fourier transform infrared (FTIR) and Proton nuclear magnetic resonance (1H-NMR) spectroscopic techniques were adopted for the characterization of these analogues. In the present study, the cytotoxic screening of sixteen compounds (3, 5-11, 13 and 15-21) was also achieved against lung (NCI-H460) and oral squamous carcinoma (CAL-27) cell lines. Compound 20 has shown magnificent inhibitory properties against NCI-H460 cell line (IC50 15.59 and 20.04 µM, respectively) at a lower dose than that of the control (cisplatin; IC50 21.00 µM). One-way analysis of variance (ANOVA), t-test and Pearson correlation coefficient (PCC) have been performed to determine the reliability of current data through statistical package for the social sciences (SPSS).

Isolation of secondary metabolites from Syzygium aromaticum (L.) Merr. & L.M.Perry. (cloves), and evaluation of their biological activities.

Phytochemical investigation of dried flower buds of Syzygium aromaticum (L.) Merr. & L.M.Perry. (clove) led to the isolation and identification of fourteen known compounds, oleanolic acid (1), betulinic acid (2), para methyl benzoic acid (3), sabrinic acid (4) eucalyptolic acid (5), nigricin (6), 3-O-trans-para-coumaroylmaslinic acid (7), methyl maslinate (8), maslinic acid (9), 3, 4, 5-trimethoxy-3',4'-O,O-methylideneflavellagic acid (10), lantanone (11) 3,4,3'-trimethoxyellagic acid (12), 11-oxo-oleanolic acid (13), and ß-sitosterol-3-O-ß-D-glucopyranoside (14). Their structures were identified by 1H NMR, 13C NMR, Mass spectroscopic techniques, and comparison with the literature data. Compounds 3, and 7-9 showed a strong mortality against root knot nematode, Meloidogyne incognita at 0.125% concentration after 72 hours (88-92% inhibition). Compound 4 showed a good anti-glycation activity with IC50 = 142.0 ± 1.8 µM when compared with standard, i.e. rutin (IC50 = 54.59 ± 2.20 µM). Compound 10 showed a comparable urease inhibitory activity (IC50 = 26.1 ± 0.19 µM) with the positive control thiourea (IC50 = 24.5 ± 0.34 µM).

Isolation and characterization of anti-inflammatory and anti-proliferative compound, for B-cell Non-Hodgkin lymphoma, from Nyctanthes arbor-tristis Linn.

ETHNOPHARMACOLOGICAL RELEVANCE: Nyctanthes arbor-tristis Linn. is native to Indo-Pak sub-continent and has high medicinal values in Ayureda. This plant has been used traditionally for the treatment of sciatica, rheumatism, chronic fever, diabetes, snakebite, dysentery, cachexia and cancer. Studies have shown many pharmacological properties such as anti-cancer efficacy against Dalton's ascetic lymphoma, cytotoxicity against T-cell leukemia, anti-inflammatory, anti-diabetic and anti-oxidant effects. AIM OF THE STUDY: Aim of the study was to explore the anti-inflammatory and anti-proliferative potential of N. arbor-tristis. MATERIAL AND METHODS: Ethanol extract of fresh and uncrushed aerial parts of N. arbor-tristis was used in the present study. A new compound nyctanthesin A was isolated following a bioactivity-guided fractionation and chromatographic separations. Its chemical structure was elucidated through spectral studies including 1D, 2D-NMR experiments and HREIMS. The intracellular reactive oxygen species (ROS) and nitric oxide (NO) generation from phagocytes were detected by chemiluminescence technique and Griess method, respectively. TNF-α and TGF-ß production was quantified by ELISA. Anti-lymphoma and cytotoxic activities were assessed by alamar blue and MTT assays, respectively. The transcription and protein expression level of Bcl-2, COX-2, p38 MAPK, PDL-1, NF-κB, c-Myc and PNF-κB was performed by qRT-PCR and protein blot assays, respectively. RESULTS: Petroleum ether insoluble fraction of the ethanol extract of fresh and uncrushed aerial parts of N. arbor-tristis revealed anti-inflammatory potential by inhibiting ROS. A previously undescribed compound nyctanthesin A was isolated from this fraction and characterized by UV, IR, NMR and HREIMS. It showed significant anti-inflammatory property by inhibiting ROS, NO and TNF-α production. The strong anti-proliferative effects on B- cell lymphoma cells, DOHH2 and Raji, revealed its anti-lymphoma potential along with non-toxic profile against BJ and NIH-3T3 fibroblast cells of normal origin. The qRT-PCR results showed marked inhibition of Bcl-2, COX-2, p38 MAPK, PDL-1, c-Myc, NF-κB, and PNF-κB at transcription level in DOHH2 cells with comparatively lesser but significant effects in Raji cells, where the expression of Bcl-2 gene was not affected. The protein expression of PNF-κB in DOHH2 cells was inhibited by 66% (P < 0.05) and COX-2 in both cell lines was inhibited by 50% (P < 0.05) at 60 µg/mL. A moderate non-significant inhibition of TGF-ß (∼20%) was observed in both cell lines at 100 µg/mL CONCLUSIONS: Scientific evidences reported here validate the anti-inflammatory and anti-cancer potential of the plant.

Phytochemicals from Carissa carandas with potent cytotoxic and anti-inflammatory activities.

Six natural products (1-6) were isolated from the fresh leaves of Carissa carandas including ursolic acid (1), ursolic acid-γ-lactone (2), 27-O-Z-p-coumaroyl ursolic acid (3), 23-hydroxy ursolic acid (4), uvaol (5) and ursolic aldehyde (6). Their structure elucidation was done by modern spectroscopic techniques including 1H-NMR, 13C-NMR and comparison with reported data. All compounds were known, while 2-4 were isolated for the first time from the genus Carissa. Isolated compounds were screened for their cytotoxic via MTT assay and anti-inflammatory potential via luminol-enhanced chem-iluminescence assay. Compounds 3 and 4 showed potent activity against lung cancer cell line (NCI-H460), and 4 showed potent anti-inflammatory activity against reactive oxygen species production from human whole blood phagocytes. Compound 5 displayed good selective cytotoxicity against NCI-H460 and did not provoke cytotoxicity against normal cell line upto 250 µM. Compounds 3-5 were identified as potential anti-cancer drug leads.

Chemical constituents of Cordia latifolia and their nematicidal activity.

Following nematicidal activity-guided isolation studies on the fruits, bark, and leaves of Cordia latifolia, two new constituents, cordinoic acid (=11-oxours-12-ene-23,28-dioic acid; 1) and cordicilin (=2-{[(E)-3-(3,4-dihydroxyphenyl)prop-2-enoyl]oxy}-3-[4-hydroxy-3-(stearoyloxy)phenyl]propanoic acid; 2) were isolated from the stem and leaves, respectively, together with nine known compounds, namely cordioic and cordifolic acid from the stem bark, latifolicin A-D and rosmarinic acid from the fruits, and cordinol and cordicinol from the leaves. Their structures were determined by means of spectroscopic analyses including 1D- and 2D-NMR techniques. The nematicidal activities of these constituents were determined against the root-knot nematode Meloidogyne incognita. Hundred percent mortality was caused by all of these after 72 h at a 0.125% concentration. Compound 1 and cordioic acid were most active and caused 100% mortality after 24 h at a 0.50% concentration. Furthermore, compound 2, the ester of rosemarinic acid, was found to be more active than the free acid.

Novel ferulic acid and benzophenone derivatives from the flower buds of Syzygium aromaticum.

Phytochemical investigation of clove resulted in the isolation of two new natural compounds, a ferulic acid derivative, sabrinic acid (1) and a benzophenone derivative (2) together with two known compounds kaempferol-3,5-dimethyl ether (3) and 4-methyl benzoic acid (4). Compounds 3 and 4 were isolated for the first time from the genus Syzygium. The structures of compounds were elucidated through modern spectroscopic techniques including 1D and 2D NMR spectroscopy.

Lawsozaheer, a new chromone produced by an endophytic fungus Paecilomyces variotii isolated from Lawsonia Alba Lam. inhibits the growth of Staphylococcus aureus.

One new chromone, lawsozaheer (1), and five known compounds 4-(2-hydroxyethyl) phenol (2), viriditoxin (3), stigmasta-4,6,8(14),22-tetraen-3-one (4), ß-sitosterol (5) and stigmasterol (6) were isolated from the fungal broth of Paecilomyces variotii. Their structures were elucidated using spectroscopic data. The configuration of 1 was determined by Horeau's method. The broth extract and compound 1 showed highly selective activity against Staphylococcus aureus (NCTC 6571) bacterium with 83.19 and 84.26% inhibition respectively at 150 µg/mL, comparing well with that of standard drug ofloxacin (87.013% inhibition at 100 µg/mL). Broth extract also showed 75, and 40% inhibition of Candida albicans and Fusarium lini, respectively.

Nematicidal activity of oleanolic acid derivatives on Meloidogyne incognita.

In this study, oleanolic acid and its derivatives were studied for their invivo nematicidal activity against root-knot nematode (RKN) Meloidogyne incognita. A series of C-28-oleanolates including five new (5, 7-10) and seven known (1-4, 6, 11, 12) compounds were synthesised and their nematicidal activity was determined and compared with the standard nematicide furadan for the first time. The structures of the compounds were elucidated through 1H NMR, 13C NMR and EIMS. Compounds 4, 5, 7, 8 and 10 showed ∼ 90% inhibition of RKN at 0.125% concentration after 72 h showing their potential use in nematicidal control.

An efficient, mild and solvent-free synthesis of benzene ring acylated harmalines.

A facile synthesis of a series of benzene ring acylated analogues of harmaline has been achieved by Friedel-Crafts acylation under solvent-free conditions at room temperature using acyl halides/acid anhydrides and AlCl3. The reaction afforded 10- and 12-acyl analogues of harmaline in good yield, along with minor quantities of N-acyl-tryptamines and 8-acyl analogues of N-acyltryptamines.

Di-tert-butyl cyclo-hex-2-ene-1,4-diyl dicarbonate.

In the title mol-ecule, C(16)H(26)O(6), the central cyclo-hexene ring is in a half-chair conformation. The carbonyl groups are in a trans arrangement with respect to each other and the dihedral angle between the mean planes of the carbonate groups is 10.8 (2)°.