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.

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).

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.

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).

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.

In-vivo antinociceptive, anti-inflammatory and antipyretic activity of pistagremic acid isolated from Pistacia integerrima.

The current study was designed to explore the antinociceptive, antiinflammatory and antipyretic activity of pistagremic acid (PA), isolated from Pistacia integerima bark in various animal paradigms. The results illustrated significant inhibition of noxious stimulation in acetic acid induced writhing test with maximum effect of 68% at 10mg/kg i.p. In tail immersion test, pretreatment with PA demonstrated marked activity during various assessment times in a dose dependent manner. The maximum pain inhibition was 59.46% at 10mg/kg i.p. after 90 min of PA treatment. However, the injection of naloxone did not antagonize this induced effect. PA significantly ameliorated post carrageenan induced edema dose dependently during various stages of inflammation. The effect was most dominant (60.02%) after 3(rd) h of drug administration when examined for 5h. Similarly, it provoked dose dependent antipyretic effect in febrile mice with maximum of 60.04% activity at 10mg/kg i.p. after 3rd hour of PA post treatment. Furthermore, molecular docking was carried out to understand the binding mode of PA. From the docking study it was observed that PA fits well in the active site of COX-2 enzyme due to hydrogen and hydrophobic moiety interactions to the important active site of molecule. In conclusion, PA possesses strong peripheral and central antinociceptive activity independent of opioidergic effect which was augmented by its anti-inflammatory and antipyretic activities.

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.

Anti-ulcer xanthones from the roots of Hypericum oblongifolium Wall.

Three new xanthones, hypericorin C (1), hypericorin D (2) and 3,4-dihydroxy-5-methoxyxanthone (3), along with eight known compounds; 2,3-dimethoxyxanthone (4), 3,4-dihydroxy-2-methoxyxanthone (5), 3,5-dihydroxy-1-methoxyxanthone (6), 3-acetylbetulinic acid (7), 10H-1,3-dioxolo[4,5-b]xanthen-10-one (8), 3-hydroxy-2-methoxyxanthone (9), 3,4,5-trihydroxyxanthone (10) and betulinic acid (11) were isolated from the roots of Hypericum oblongifolium. The structures of the new compounds 1, 2 and 3 were deduced by spectroscopic techniques [ESI MS, (1)H NMR, (13)C NMR, and 2D NMR (HMQC, HMBC, COSY and NOESY)]. The entire series of compounds were evaluated for anti-ulcer activity.

Highly oxygenated stigmastane-type steroids from the aerial parts of Vernonia anthelmintica Willd.

Nine new highly oxygenated stigmastane-type steroids, vernoanthelcin A-I (1-9), and two new stigmastane-type steroidal glycosides, vernoantheloside A and B (10 and 11) were isolated from the aerial parts of Vernonia anthelmintica Willd. The structures of compounds 1-11 were determined on the basis of IR, MS, 1D-NMR, and 2D-NMR, and their absolute configurations were deduced using single-crystal X-ray diffraction and the CD exciton chirality method. Compounds 1, 5, 7, 9 and 10 were tested for their effects on estrogen biosynthesis in human ovarian granulosa-like cells (KGN cells).

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.

Diterpenoids from Euphorbia neriifolia.

Nine diterpenoids were isolated from the stems of Euphorbia neriifolia Linn. with their structures established by 1D and 2D NMR techniques. Relative stereochemistries were determined by ROESY, and single-crystal X-ray experiments.

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).

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.

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.

Analgesic and anti-inflammatory activities of 11-O-galloylbergenin.

AIMS OF THE STUDY: Current study was designed to explore the analgesic and anti-inflammatory effects of a constituent isolated from Mallotus philippinensis, in order to validate its folk use. MATERIALS AND METHODS: 11-O-galloylbergenin was isolated from ethanolic extract of Mallotus philippinensis. Analgesic and anti-inflammatory activities of the test compound were assessed using formalin test and carrageenan-induced paw edema models. RESULTS: 11-O-galloylbergenin showed significant analgesic activity at doses of 20 and 40 mg/kg against formalin test in rats. Similarly, 11-O-galloylbergenin exhibited significant anti-inflammatory activity in carrageenan-induced paw edema model at doses of 10, 20 and 30 mg/kg. CONCLUSION: 11-O-galloylbergenin has demonstrated its significant potential to be further investigated for its discovery as a new lead compound for management of pain and inflammation.

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.

Anti-tuberculosis compounds from Mallotus philippinensis.

Bioassay-directed fractionation of the organic extract of Mallotus philippinensis gave five compounds (1-5), the most active of which against Mycobacterium tuberculosis was a new compound, 8-cinnamoyl-5,7-dihydroxy-2,2-dimethyl-6-geranylchromene (1) for which the name mallotophilippen F is suggested. Compound (2), 8-cinnamoyl-2,2-dimethyl-7-hydroxy-5-methoxychromene, was isolated from a natural source for the first time, while the remaining three compounds, rottlerin (3), isoallorottlerin=isorottlerin (4) and the so-called "red compound," 8-cinnamoyl-5,7-dihydroxy-2,2,6-trimethylchromene (5), had been isolated previously from this plant. All compounds were identified by analysis of their spectra including 2D-NMR, which was used to correct the literature NMR spectral assignments of compounds 2-4. The C-13 NMR of 5 is reported for the first time.

The antifungal activity of Sarcococca saligna ethanol extract and its combination effect with fluconazole against different resistant Aspergillus species.

Microbial resistance is a major drawback in chemotherapy of microbial or fungal infection disease. In this study, the antifungal activity of ethanol extract of a selected plant (Sarcococca saligna) has been investigated against clinical isolates of Aspergillus niger, Aspergillus treus, Aspergillus flavus, and Aspergillus fumigatus. Also, the enhancement of the antifungal activity of fluconazole by this extract was further evaluated against mentioned test strains. Conventional disk diffusion method was used to assay the antifungal activity of S. saligna ethanol extract in the absence and presence of fluconazole. The highest antifungal activity was observed against A. treus. The ethanol extract of S. saligna enhanced the antifungal activity of fluconazole against A. niger and A. treus and A. flavus. At the highest tested contents (4 mg/disk), 1.15-, 0.64-, and 2.47-fold increases in inhibition zone surface area were observed for A. niger, A. treus, and A. flavus, respectively. However, no enhancing effect was observed for this plant extract against Aspergillus fumigates at tested contents (0.5, 1, 2, 3, and 4 mg/disk). In a separate experiment, the general cytotoxicity of the ethanol extract of S. saligna was examined with brine shrimp assay. This plant extract showed low cytotoxicity against Artemia salina (LC(50) = 186 microg/ml).