Evaluation of antioxidant and antimicrobial activities on various extracts of Himalayan medicinal plants.

The DPPH radical scavenging potentials of the fractions were determined in comparison to positive controls such as quercetin with EC50 = 4.12±1.27, ascorbic acid with EC50 = 6.20±1.67, gallic acid with EC50 = 4.75±1.24 and α-tocopherol with EC50 = 32.50±1.57 µg/mL. The experiment showed that aqueous fractions of the bark extracts of Abies pindrow (fraction: C2) and Cedrus deodara (fraction: E2) showed significantly lower EC50 values of 2.5±0.5 and 2.5±0.6 µg/mL, respectively. In reducing power assay, lower EC50 values of 5.5 and 4.5µg/mL were recorded for the aqueous fraction (fraction: C 2) and final residue (fraction: C5), of Abies pindrow, respectively. The ethyl acetate, acetone and final fractions of knot wood of Picea smithiana were found significantly active against all bacterial strains. Of the most sensitive fractions towards all the fungal strains was ethyl acetate fraction obtained from the bark of Cedrus deodara with a zone of inhibition ranging from 75 to 88 % that was more than the standard fluconazole.

Preliminary phytochemical screening, antimicrobial and antioxidant activities of Euphorbia milli.

Euphorbia milii is a Pakistani herb used for various infectious diseases. In this study we have carried out phytochemical, antibacterial and antioxidant investigation of different extracts/fractions. Phytochemical studies showed the presence of cardiac glycosides, steroids/phytosterols, anthocyanin, proteins, terpenoids, flavonoids and tannins. Susceptibility testing by well diffusion assay of its chloroform and methanol fractions revealed good antimicrobial activity against Klebsiella pneumonia and Staph epidermis. Ethyl acetate fraction of roots also exhibited considerable antimicrobial activity against most of tested pathogens. Various fractions (Hexane, chloroform, methanol and water) of E. milii were screen for their antioxidant potential using DPPH radical scavenging assay at different concentrations among these, chloroform fraction exhibited good scavenging activity. The IR spectroscopy of the various extracts/fractions indicated the presence of OH, saturated CH stretching, C=C, C=O, NO2, C-N, Ar-O, C-O- and R-O-Stretching respectively. The findings provide helpful evidence for the use of E. milii in traditional medicines.

Synthesis of new bergenin derivatives as potent inhibitors of inflammatory mediators NO and TNF-α.

Bergenin is an isocoumarin natural product which aides in fat loss, healthy weight maintenance, enhancing the lipolytic effects of norepinephrine, inhibiting the formation of interleukin 1α and cyclooxygenases-2. Here we describe the anti-inflammatory activity of new bergenin derivatives 1-15 in the respiratory burst assay. Bergenin was isolated from the crude extract of Mallotus philippenensis after repeated column chromatography and was then subjected to chemical derivatization. The structures of all compounds were elucidated by NMR and mass spectroscopic techniques. Compound 2 was also studied using single crystal X-ray diffraction. Compounds 4, (54.5±2.2%) 5 (47.5±0.5%) 5, and 15 (86.8±1.9%) showed significant (P≤0.005) NO inhibitory activities whereas 6, 7, 11, 12 and 13 displayed moderate inhibitory activities that ranges between 16% and 31%. Furthermore compounds 4 and 15, were discovered as significant (P≤0.005) TNF-α inhibitors with 98% and 96% inhibition, respectively, while compounds 3, 5, 7, 8, 11, and 12 showed low level of TNF-α inhibition (0.4-28%). Compounds 8, 13 and 15 exhibited moderate anti-inflammatory IC(50) activities with 212, 222, and 253 µM, respectively, compared to the standard anti-inflammatory drug indomethacin as well as the parent bergenin compound. No cytotoxic effects could be detected when the compounds were tested on 3T3 cells up to concentrations of 100 µM.

Pistagremic acid a new leishmanicidal triterpene isolated from Pistacia integerrima Stewart.

The present study was designed to investigate the whole plant of Pistacia integerrima Stewart in order to examine the pharmacological basis of the use of the plant in folk medicine for the treatment of infectious diseases and disorder. Phytochemical and pharmacological studies led to the isolation of a new triterpene pistagremic acid (3-methyl-7-(4,4,10,13,14-pentamethyl-3-2,3,4,5,6,7,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-17-yl)-oct-3-enoic). Pistagremic acid showed significant leishmanicidal activity (IC(50): 6.71 ± 0.09 µM) against Leishmania major (DESTO) promastigotes in comparison to standard compound amphotericin B (IC(50): 0.21 ± 0.06 µM).

neo-Clerodane diterpenoids from Ajuga bracteosa.

Different neo-clerodane diterpenoids were isolated from a dichloromethane extract of Ajuga bracteosa depending on the isolation procedure used, owing to the labile nature of these tetrahydrofurofuran derivatives. Under "hydroxyl-free" purification conditions, both clerodin- and dihydroclerodin-type diterpenes were obtained [four new compounds, ajubractins A-D (1-4), along with clerodin (5), 3-epi-caryoptin (6), ajugapitin (7), 14,15-dihydroclerodin (8), 3-epi-14,15-dihydrocaryoptin (9), ivain II (10), and 14,15-dihydroajugapitin (11)]. When methanol-water mixtures were used for a C18 reversed-phase prepurification procedure and for semipreparative HPLC, the new ajubractin E (12) was also isolated along with 3 and 8-11, as previously, but 7 was the only tetrahydrofurofuran derivative obtained. Epimeric (15R and 15S) mixtures were obtained instead of 14-hydro-15-hydroxyclerodin derivatives [15-hydroxyajubractin C (13), 14-hydro-15-hydroxyajugachin A (14), and 14-hydro-15-hydroxyajugapitin (15)], along with 15-epi-lupulin B (16). The structures of the new compounds were elucidated by NMR and MS data analysis and by comparison with values previously reported. Antifeedant activity against Spodoptera littoralis larvae was evaluated for the compounds obtained.

2-Methyl-6-(4,4,10,13,14-penta-methyl-3-oxo-2,3,4,5,6,7,10,11,12,13,14,15,16,17-tetra-deca-hydro-1H-cyclo-penta-[a]phenanthren-17-yl)hept-2-enoic acid.

In the title compound, C(30)H(46)O(3), an isolation product of Pistacia integerima Stewart, the five-membered ring is nearly in the envelope form. A 6-carb-oxy-hept-5-en-2-yl group is attached to the five-membered ring. An S(6) ring motif is formed due to intra-molecular C-H⋯O hydrogen bonding. In the crystal, inter-molecular O-H⋯O hydrogen bonds form carboxyl-ate dimers with R(2) (2)(8) ring motifs.

2-[(1R*,4R*)-1,4-Dihy-droxy-cyclo-hex-yl]acetic acid.

The title compound, C(8)H(14)O(4), is an isolation product of the aerial parts of Senecio desfontanei. The acetic acid group is oriented at a dihedral angle of 48.03 (9)° with respect to the basal plane of the cyclo-hexane-1,4-diol chair. An intra-molecular O-H⋯O hydrogen bond generates an S(6) ring with an envelope conformation. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds, resulting in R(3) (3)(20) ring motifs and C(2) O-H⋯O-H⋯O-H⋯ chains. Overall, a three-dimensional polymeric network arises. A C-H⋯O contact is also present.

Identification of novel quinazolin-4(3H)-ones as inhibitors of thermolysin, the prototype of the M4 family of proteinases.

A combinatorial series of novel quinazolin-4(3H)-ones were synthesised and their structures were established based on spectroscopic data (IR, NMR, EI-MS, and FAB-MS). The compounds were tested for inhibition of the zinc metalloproteinase thermolysin (TLN) utilizing a chemical array-based approach. Some of the compounds were found to inhibit TLN, with IC(50) values ranging from 0.0115 microM (compound 3) to 122,637 microM (compound 29). Compound 3 [3-phenyl-2-(trifluoromethyl) quinazolin-4(3H)-one] (IC(50)=0.0115 microM) and compound 35 [3-(isopropylideneamino)-2,2-dimethyl-2,3-dihydroquinazolin-4 (1H)-one] (IC(50)=0.2477 microM) were found to be the most potent inhibitors.

Urease inhibitors from Hypericum oblongifolium WALL.

The bioassay-guided fractionation of H. oblongifolium has led to the isolation of potent urease inhibitors 1-3. The structures were elucidated by NMR and mass spectroscopic techniques. Compound 2 showed a potent enzyme inhibition activity (IC(50) 20.96 +/- 0.93), which is comparatively higher than that for the standard thiourea (IC(50) 21.01 +/- 0.51 microM). Compounds 1 and 3 also showed a significant activity, with IC(50) 37.95 +/- 1.93 and 138.43 +/- 1.23 microM, respectively. The sub crude fractions (F1, F2, F3, and F4) were tested in vitro for their urease inhibition activity. Fractions F2 and F4 showed significant activity with IC(50) 140.37 +/- 1.93 and 167.43 +/- 3.03 microM, respectively.

Antiplasmodial isoflavanones from the roots of Sophora mollis.

Six new prenylated isoflavanones named sophoronols A-F (1-6), together with eight phenolic constituents, were isolated from the roots of Sophora mollis. Their structures and stereochemistry were established by 1D and 2D NMR techniques, especially HMBC and NOESY as well as CD results. Componds 3 and 5 exhibited moderate anitplasmodial activity against the CQS D10 strain of Plasmodium falciparum, with IC(50) values of 12.9 and 12.8 microM, respectively.

Immunosuppressive withanolides from Withania coagulans.

Six new withanolides, withacoagulins A-F (1-6, resp.), together with ten known withanolides, 7-16, were isolated from the aerial parts of Withania coagulans. Their structures were determined by spectroscopic techniques including 1D- and 2D-NMR (1H, 13C, HMQC, and HMBC) and MS experiments. These compounds, including the crude extracts of this herb, exhibited strong inhibitory activities on the T- and B-cell proliferation.

3-Amino-2-methyl-4-oxo-3,4-dihydro-quinazolin-1-ium p-toluene-sulfonate monohydrate.

In the title hydrated mol-ecular salt, C(9)H(10)N(3)O(+)·C(7)H(7)O(3)S(-)·H(2)O, the cation is protonated at a quinazolinone N atom and an intra-molecular N-H⋯O hydrogen bond occurs. In the crystal structure, inter-molecular N-H⋯O and O-H⋯O hydrogen bonds and C-H⋯O, C-H⋯π and weak aromatic π-π stacking inter-actions [centroid-centroid separations = 3.8648 (12) and 3.9306 (13) Å] help to establish the packing; a short S=O⋯π contact is also seen.

3-Benzyl-5-butyl-1,3,5-thia-diazinane-2-thione.

In the title compound, C(14)H(20)N(2)S(2), the 1,3,5-thia-diazinane-2-thione ring adopts an envelope conformation. The S=C bond length is 1.6776 (15) Å, whereas the S-C bond lengths are 1.7470 (15) and 1.8479 (17) Å. The intramolecular C-H⋯S hydrogen bond between the thione and the benzyl units along with the C-H⋯π interaction between the butyl group and the centroid of the benzene ring may be effective in stabilizing the molecule.

2-[6-Thioxo-5-(2,4,6-trimethyl-phen-yl)-1,3,5-thia-diazinan-3-yl]acetic acid.

In the mol-ecule of the title compound, C(14)H(18)N(2)O(2)S(2), the 1,3,5-thia-diazinane-2-thione ring adopts an envelope conformation with one of the N atoms at the flap position. The plane throught the five co-planar atoms of the heterocycle is oriented at a dihedral angle of 80.59 (8)° with respect to the aromatic ring. In the crystal structure, weak inter-molecular O-H⋯S inter-actions link the mol-ecules into chains along the b axis.

(2-Amino-phen-yl)[(5S)-5-hydr-oxy-3,5-dimethyl-4,5-dihydro-1H-pyrazol-1-yl]methanone.

In the mol-ecule of the title compound, C(12)H(15)N(3)O(2), the pyrazole ring is oriented at a dihedral angle of 49.64 (6)° with respect to the benzene ring. Intra-molecular O-H⋯O, N-H⋯O and C-H⋯O inter-actions result in the formation of a trifurcated hydrogen bond. In the crystal structure, inter-molecular N-H⋯O and O-H⋯N hydrogen bonds link the mol-ecules, forming a network structure.

3-(2-Benzamido-phen-yl)-4-(4-hydroxy-phen-yl)-5-methyl-4H-1,2,4-triazol-1-ium chloride.

In the mol-ecule of the title compound, C(22)H(19)N(4)O(2) (+)·Cl(-), the 1,2,4-triazole ring is oriented at dihedral angles of 75.57 (14), 53.23 (13) and 68.11 (13)° with respect to the benzamide, aniline and phenol atomatic rings, respectively. An intra-molecular C-H⋯O hydrogen bond results in the formation of a non-planar ten-membered ring. In the crystal structure, inter-molecular O-H⋯Cl and N-H⋯Cl hydrogen bonds link the mol-ecules. There is a C-H⋯π contact between the methyl group and the phenyl ring, and a π-π contact between the hydroxy-phenyl and phenyl rings [centroid-centroid distance = 4.687 (2) Å].

Bioassay-guided isolation of antibacterial constituents from Diospyros lotus roots.

The aim of this study was to explore the extract/fractions and compounds of Diospyros lotus against various Gram-positive and Gram-negative bacteria strain. The results showed marked susceptibility of extract and its fractions against test pathogens. Among them, chloroform fraction was most dominant and effective against all tested bacteria. The chloroform fraction was subjected to column chromatography which led to the isolation of lupeol (1), 7-methyljuglone (2), ß-sitosterol (3), stigmasterol (4), betulinic acid (5), diospyrin (6) and 8-hydroxyisodiospyrin (7). Among the isolated compounds, betulinic acid (5) showed significant activity against most of the tested pathogen. In conclusion, our study validated the traditional uses of the plant in the treatment of infectious diseases which was also strongly supported by the isolated compound, betulinic acid (5).

Anti-hyperalgesic activity of crude extract and 7-methyljuglone of Diospyros lotus roots.

This study was designed to evaluate the antihyperalgesic effect of crude extract of Diospyros lotus followed by the isolation and characterisation of 7-methyljuglone in acetic acid and formalin tests. The pretreatment of crude extract evoked dose-dependent inhibition of noxious stimulation with maximum effect of 56.78% in acetic acid-induced writhing test, which were 51.89% and 60.69% in first and second phases, respectively, at 100 mg/kg i.p. The structure of 7-methyljuglone was confirmed by spectroscopic analysis. 7-Methyljuglone evoked profound increase in pain threshhold dose dependently; when it was studied in acetic acid-induced writhing test with 63.73% pain attenuation while 51.22% and 65.44% pain amelioration in first and second phases, respectively, at 100 mg/kg i.p. In conclusion, crude extract and 7-methyljuglone of D. lotus roots possessed both peripheral and central antinociceptive potential and thus could be a useful new therapeutic agent.

Pistagremic acid, a novel ß-secretase enzyme (BACE1) inhibitor from Pistacia integerrima Stewart.

A new triterpenic compound named pistagremic acid (PA) was once again isolated from Pistaciaintegerrima. The ß-secretase inhibition study was carried out. Compound PA was found significantly active against ß-secretase enzyme (BACE1) with IC50 value of 350 ± 2 nM in comparison to the standard inhibitors [Asn670, Sta671, Val672]-amyloid-ß/A4 precursor protein 770 fragment 662-675 (IC50 = 290.71 ± 1 nM). The selectivity of this compound was also evaluated against the acetylcholinesterase and butyrylcholinesterase enzymes. Interestingly compound PA was found to be inactive against them and showed selectivity towards ß-secretase enzyme (BACE1).

Isolation, spectroscopic and density functional theory studies of 7-(4-methoxyphenyl)-9H-furo[2,3-f]chromen-9-one: a new flavonoid from the bark of Millettia ovalifolia.

The phytochemical examination of chloroform soluble fraction (FX2) of methanolic extract of bark of Millettia ovalifolia yielded a new flavonoid; 7-(4-methoxyphenyl)-9H-furo [2,3-f]chromen-9-one (1). Compound 1 is characterized by spectroscopic analytical techniques such as UV, IR, 1D, 2D NMR spectroscopy, and mass spectrometry. A theoretical model is also developed for obtaining geometric, electronic and spectroscopic properties of 1. The geometry optimization and harmonic vibration simulations have been carried out at B3LYP/6-31G(d,p). The vibrational spectrum of compound 1 shows nice correlation with the experimental IR spectrum, through a scaling factor of 0.9613. (1)H and (13)C NMR chemical shifts are simulated using Cramer's re-parameterized function WP04 at 6-31G(d,p) basis set, and correlate nicely with the experimental chemical shifts.