2-[(2-Methoxybenzylidene)amino]phenol

In the title compound, C₁₄H₁₃NO₂, the azomethine double bond adopts an E conformation and the benzene rings form a dihedral angle of 77.70 (7)°. In the crystal, mol­ecules are linked by O—H⋯N and C—H⋯O hydrogen bonds and arranged in a zigzag fashion, forming infinite chains parallel to the c axis, resulting in a graph-set R₂²(9) motif.

{2-[(3-Bromo-benzyl-idene)amino]-5-chloro-phen-yl}(phen-yl)methanone

In the title compound, C₂₀H₁₃BrClNO, the azomethine double bond [C=N = 1.246 (4) Å] adopts an E conformation. The bromo- and chlorophenyl rings are inclined to one another by 13.70 (11)°, and form dihedral angles of 76.68 (10) and 74.24 (7)°, respectively, with the phenyl ring. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds to form double stranded chains propagating along the b-axis direction.

17-(Pyrimidin-2-yl)-8,16-dioxa-17-aza-tetra-cyclo-[7.7.1.0.0]hepta-deca-2,4,6,10,12,14-hexa-ene

In the title compound, C(18)H(13)N(3)O(2), the benzene rings form a dihedral angle of 78.49 (9)°. The dihedral angles between the benzene rings and the pyrimidine ring are 76.53 (10) and 27.73 (11)°. The two cis-fused six-membered heterocyclic rings adopt half-chair confirmations. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, forming chains parallel to the b axis.

{5-Chloro-2-[(2-hy-droxy-benzyl-idene)amino]-phen-yl}(phen-yl)methanone

The title Schiff base compound, C₂₀H₁₄ClNO₂, adopts an E configuration about the azomethine bond. The phenol and chloro­benzene rings form dihedral angles of 84.71 (9) and 80.70 (8)°, respectively, with the phenyl ring and are twisted by 15.32 (8)° with respect to one another. The mol­ecular conformation is stabilized by an intra­molecular O—H⋯N hydrogen bond, which forms an S(6) ring motif. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, forming columns parallel to the a axis.

{5-Chloro-2-[(4-nitro-benzyl-idene)amino]-phen-yl}(phen-yl)methanone

The mol­ecule of the title Schiff base compound, C₂₀H₁₃ClN₂O₃, assumes an E configuration about the C=N bond. The aromatic rings of the nitro­benzene and chloro­benzene groups are twisted by 13.89 (13)° and form dihedral angles of 76.38 (13) and 84.64 (13)°, respectively, with the phenyl ring. In the crystal, mol­ecules are linked into chains parallel to the b axis by C—H⋯π inter­actions.

Lipoxygenase inhibitory tetraketones: potential remedial source for inflammation and asthma

OBJECTIVE

A series of tetraketones has been synthesized by way of a one pot synthesis and screened for inhibitory activity against the enzyme lipoxygenase.

METHOD

An efficient and high yielding one pot synthesis to tetraketones [2-22] has been developed by way of tetraethyl ammonium bromide (Et4N+Br-) mediated condensation of cyclohexane-1, 3-dione [1] with a variety of aldehydes. Lipoxygenase enzyme solution was prepared so that enzyme concentration in reaction mixture was adjusted to give rates of 0.05 absorbance/minute. The test compounds were prepared in methanol of concentrations 50, 25, 12.5, 6.25 and 3.125 microM. The reaction mixture contained 160 microL (100 mM) sodium phosphate buffer (pH 8.0), 10 microL of test-compound solution and 20 microL of lipoxygenase solution. The contents were mixed and incubated for 10 minutes at 25 degrees C. The reaction was then initiated by the addition of 10 microL substrate solution (linoleic acid, 0.5 mM, 0.12% w/v tween 20 in the ratio of 1:2), with the formation of (9Z, 11E)-(13S)-13-hydroperoxyoctadeca-9,11-dienoate, the change of absorbance at 234 nm was followed for 6 minutes. The concentrations of the test compounds that inhibited the lipoxygenase activity by 50% (IC50) were determined by monitoring the effect of increasing concentrations of these compounds in the assays on the degree of inhibition. The IC50 values were calculated by means of the EZ-Fit Enzyme-Kinetics Program (Perrella Scientific Inc., Amherst, U.S.A.).

RESULT

The tetraketones [2-22] were synthesized in high yields (91-98%) using mild reaction conditions. Most of these compounds showed significant inhibitory activity against the enzyme lipoxygenase. It was found that the presence of substituents which increase delocalization of electrons enhances the inhibitory activity.

CONCLUSION

It is concluded that the study is likely to lead to the discovery of therapeutically efficient agents against important disorders such as inflammation and asthma.

Natamycin treatment of experimental Candida albicans induced keratomycosis in rabbits

OBJECTIVE

The efficacy of topical natamycin 5% was studied using a reproducible model of keratomycosis produced by Candida albicans in the rabbits.

METHOD

Candida albicans was isolated from infected human eye and 4 x 10(5) cells of the Candida albicans was injected into the corneal stroma of the eyes of 15 rabbits. All eyes developed a corneal ulcer without pretreatment with immunosuppressive agents. Forty-eight hours after inoculation, the animals were divided into two groups: test group I, 10 eyes receiving notamycin drops in a 5% suspension; control group II, five eyes receiving 0.9% normal saline solution. The rabbits' corneas were removed for Candida albicans recovery and placed in 1 ml of sterile 0.9% normal saline solution, minced within two hours with scalpel and thoroughly homogenized with a piston and mortar Serial dilutions of this corneal solution from 10(-1) - 10(-4) were made in 0.9% sterile saline solution and 100 microl aliquots were plated onto tryptic soy agar. All cultures of cornea from the treated eyes were negative after seven days of inoculation while five cultures were still positive in the control eyes at the end of the experiment.

RESULT

It was found that 5% natamycin was effective in treating experimental Candida albicans induced keratomycosis in rabbits.

CONCLUSION

It is concluded that natamycin has a significant effect (p < 0.01) against Candida albicans in treating experimental keratomycosis.

Triterpenes from Mimusops elengi

Pentacyclic triterpenes (1) and (2) have been isolated from Mimusops elengi and assigned structures 3beta,6beta,19alpha,23-tetrahydroxy-urs-12-ene and 1beta-hydroxy-3beta-hexanoyllup-20 (29)-ene-23, 28-dioic acid, respectively, on the basis of spectroscopic studies including 2D-NMR. The compound 1 showed moderate inhibiting activity against beta-glucuronidase enzyme

A new withanolide glycoside from physalis peruviana

A new withanolide glycoside, 17beta-hydroxy-14, 20-epoxy-1-oxo-[22R]-3beta-[O-beta-D-glucopyranosyl]-witha-5, 24-dienolide (1), has been isolated from the whole plant of Physalis peruviana. Its identity was determined using a combination of spectroscopic data including 2D NMR techniques and chemical transformations.