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Purpose: To assess the difference in intraocular pressure before and after Nd-YAG laser posterior capsulotomy. Study Design: Quasi-experimental study. Place and Duration of Study: Layton Rahmatulla Benevolent Trust Eye Hospital, Karachi, from July 2021 to October 2021. Methods: Patients of both gender with posterior capsular opacification (PCO) after cataract surgery, were included. Age ranged between 40 and 60 years. Patients with less than 6 months of surgery were excluded. Patients with posterior segment pathology like glaucoma, uveitis, high myopia, diabetic retinopathy, macular pathology, and hereditary fundus dystrophies were excluded from the study. After detailed history, complete ocular examination was performed. After pupil dilatation, YAG laser capsulotomy was done.IOP was measured with Goldmann Applanation Tonometer after instilling a topical anesthetic agent. Post-YAG, IOP was again measured at 1 hour and on day 1. Data was analyzed using SPSS version 25. Paired T-tests were used to assess the significance of any change in IOP. Results: Ninety eyes of 90 patients were inducted into the study in which 51 (57%) were male and 39 (43%) were female. The age varied from 40 to 60 years (mean 52.3 ± 10.25 years). There was no statistically significant difference between pre-YAG and post-YAG IOP. Similarly, no difference in IOP was found depending upon the age of the patients. No significant change was observed after 1 hour and 1 day in both groups with P > 0.05. Conclusion: This showed no significant change in intraocular pressure at one hour and one day, after Nd-YAG laser posterior capsulotomy. [ABSTRACT FROM AUTHOR]

Chronic kidney disease is one of the leading causes of death, which is often neglected due to lack of knowledge and resources. The objective of this study was to determine the effects of home-based exercise on physical functioning, quality of life and fatigue assessment for patients on hemodialysis. A randomized control trial was conducted, with participants divided into two groups. Twenty-six (26) participants were enrolled, and were assigned equally to each group. The control group received hospital-based care, and the intervention group received a home exercise program. Both groups received three sessions per week, for six weeks. Outcome measures included six-minute walk test, standing balance, 4-metre gait speed, chair stand, fatigue assessment scale and quality of life. Significant improvement in sixminute walk test, fatigue assessment scale, 4 meter gait speed, chair stand test and standing balance was noted in the intervention group as compared with control group. This study concluded that aerobic and resistance exercises are more effective in improving the functional outcomes of patients on hemodialysis as compared to routine physical therapy. [ABSTRACT FROM AUTHOR]

Background: Objective of this study was to compare Reverse Tenzel flap and Cutler Beard flap for upper eyelid defects. Methods: This interventional study was carried out at occuloplasty department of LRBT (Layton Rahamatullah Benevoloent Trust), Karachi. Patients diagnosed with upper eye lid defect between 50 and 75 years were included after ethical approval from institutional ethical review committee and briefing patients about study dynamics. The patients were randomly divided in two groups, group A in whom reverse tanzel flap was done, while in group B Cutler beard procedure was done. Main outcome measure was eyelid contour, complete lid closure and surgical procedure time. SPSS version 25.0 was used for data analysis. Results: Reverse Tenzel flap mean age 64.00±6.17 years, mean duration of surgery 33±5.78 minutes, and mean healing time 2.2±0.41 weeks. Cutler Beard flap mean age 59.60±6.26 years, mean duration of surgery 32±5.78 minutes, and mean healing time 5.7±0.8 in 3 weeks. 60% of patients were female. 30 (50%) patients each underwent Reverse Tenzel flap and Cutler Beard flap. In Reverse Tenzel flap, no complications were observed. In Cutler Beard flap, 06 (20%) patients reported mild entropion, 04 (13.3%) retraction of flap and 02 (6.7%) were found to have mild incomplete lid closure. Conclusion: Reverse Tenzel flap was superior to Cutler Beard flap as it reported no complications, being single stage surgery with early healing. Cutler-Beard flap reported mild entropion and retraction of flaps which required second surgery and delayed healing. [ABSTRACT FROM AUTHOR]

Background: The surgery of macular hole is a complex and intricate micro-surgery and chances of recurrence of macular hole are always high. Therefore, in order to provide a medium to close this hole, we carried out this research on subjects using amniotic membrane, in light of the studies being conducted around the world. This in turn led to benefitting the patients by improving their vision over time. Purpose: To assess the rate of recurrent macular hole closure with amniotic membrane plug. It was a Quasi-experimental study, conducted at Layton Rahmatullah Benevolent Trust (LRBT) Free Eye Hospital Karachi, from January 2019 to January 2020. Methods: This study was conducted using 13 eyes of 13 patients with recurrent macular hole who underwent amniotic membrane plugging via pars plana approach. Outcomes measured were changes in best corrected visual acuity (BCVA) and change in hole size with the help of optical coherence tomography (OCT). Results: Anatomic closure was attained in 100% of the cases whereas BCVA improved from 1.7±0.33 (6/300) to 0.9±0.15 (6/48). Conclusion: The use of AM is a functional method for management of large RMH. [ABSTRACT FROM AUTHOR]

Fifteen benzophenone thiosemicarbazones were synthesized and their in vitro antiglycation activity was evaluated. The most active compound 2 (IC50 = 118.15±2.41µM) showed two folds potent activity than the standard, rutin (IC50 = 294.5±1.5µM). Compounds 1 and 3-7 showed good to moderate antiglycation activity in the range of 204.14 - 488.54µM. These compounds were also evaluated for antioxidant activity. Their structure-activity relationships have been developed. The results reveal the potential of these compounds as leads for further studies towards the development of antidiabetic drugs. [ABSTRACT FROM AUTHOR]

Over-expression of thymidine phosphorylase (TP) plays a key role in many pathological complications, including angiogenesis which leads to cancer cells proliferation. Thus in search of new anticancer agents, a series of 4-hydroxybenzohydrazides (1–29) was synthesized, and evaluated for in vitro thymidine phosphorylase inhibitory activity. Twenty compounds 1–3, 6–14, 16, 19, 22–24, and 27–29 showed potent to weak TP inhibitory activities with IC50 values in the range of 6.8 to 229.5 μM, in comparison to the standards i.e. tipiracil (IC50 = 0.014 ± 0.002 μM) and 7-deazaxanthine (IC50 = 41.0 ± 1.63 μM). Kinetic studies on selected inhibitors 3, 9, 14, 22, 27, and 29 revealed uncompetitive and non-competitive modes of inhibition. Molecular docking studies of these inhibitors indicated that they were able to interact with the amino acid residues present in allosteric site of TP, including Asp391, Arg388, and Leu389. Antiproliferative (cytotoxic) activities of active compounds were also evaluated against mouse fibroblast (3T3) and prostate cancer (PC3) cell lines. Compounds 1, 2, 19, and 22–24 exhibited anti-proliferative activities against PC3 cells with IC50 values between 6.5 to 10.5 μM, while they were largely non-cytotoxic to 3T3 (mouse fibroblast) cells proliferation. Present study thus identifies a new class of dual inhibitors of TP and cancer cell proliferation, which deserves to be further investigated for anti-cancer drug development. [ABSTRACT FROM AUTHOR]

A series of synthetic 2-aryl-4(3H)-quinazolinones (1-25) was evaluated for in vitro antileishmanial activities against promastigotes of Leishmania major. Compound 1, with nitro group installed at C-4', was found to be the most active analog having the IC50 value of 35.8 ± 0.1 µM against the standard, pentamidine (IC50 = 5.09 ± 0.09 µM). Fourteen other derivatives i.e. 2, 5-8, 10- 12, 14, 16, 19, 22, 24, ad 25, showed a moderate to weak antilieshmanial activity with IC50 values between 62.8 - 90.45 µM. The results indicate the potential of these compounds as leads for further studies towards the development of antileishmanial drugs. [ABSTRACT FROM AUTHOR]

Thymidine phosphorylase (TP) over expression plays an important role in several pathological conditions, such as rheumatoid arthritis, chronic inflammatory diseases, psoriasis, and tumor angiogenesis. In this regard, a series of twenty-five 2-arylquinazolin-4(3 H )-one derivatives 1 – 25 were evaluated for thymidine phosphorylase inhibitory activity. Six compounds 5 , 6 , 20 , 2 , 23 , and 3 were found to be active against thymidine phosphorylase enzyme with IC 50 values in the range of 42.9–294.6 μM. 7-Deazaxanthine (IC 50 = 41.0 ± 1.63 μM) was used as a standard inhibitor. Compound 5 showed a significant activity (IC 50 = 42.9 ± 1.0 μM), comparable to the standard. The enzyme kinetic studies on the most active compounds 5 , 6 , and 20 were performed for the determination of their modes of inhibition, and dissociation constants K i . All active compounds were found to be largely non-cytotoxic against the mouse fibroblast 3T3 cell line. This study identifies a novel class of thymidine phosphorylase inhibitors which may be further investigated as leads to develop therapeutic agents. [ABSTRACT FROM AUTHOR]

Benzophenone hydrazone analogs 1-25 were synthesized and evaluated for antioxidant (DPPH radical scavenging), and urease inhibitory activities. Out of twenty-five analogs, compounds 8, 23, and 1 showed potent free radical scavenging activities with IC50 values 19.45 ± 1.25, 21.72 ± 1.49, and 26.0 ± 0.52 μM, respectively, while compound 8 (IC50 = 36.36 ± 0.94 μM), and 15 (IC50 = 55.5 ± 0.69 μM), showed good to moderate urease inhibitory potential. [ABSTRACT FROM AUTHOR]

Disodium-4,4'-bis(1,3,5-t riazinylamino)st ilbene-2,2'-disulfonates 5a-5d were synthesized by react ing 4,4'-diaminostilbene-2-2'-disulfonic acid 1 with 2,4,6-trichloro-1,3,5-triazine 2 via the intermediacies of 3 and 4a-4d. The intermediate 3 was reacted with different amines at different temperature condit ions to afford other intermediates 4a-4d and finally the desired fluorescent bright ener's 5a-5d. The st ructures of the products were characterized by UV-visible, IR and H1-NMR spect roscopy techniques. Elemental analyses were found to be in good agreement with the calculated values. These compounds were applied on cotton fiber as fluorescent brighteners and their physical properties were performed by wash-, chlorine-, and light -fastness. The whiteness of the fiber was measured by spect rophotometer. [ABSTRACT FROM AUTHOR]

Background: To determine the agents of poisoning and demographic distribution of children brought to Civil Hospital Karachi (CHK) with a history of accidental poison intake and to examine the factors associated with it. Methods: This hospital based descriptive study of first 100 patients from both sexes who presented to Pediatric department, CHK from 1st January 2006 till 31st December 2008 with exposure to a known poisonous agent and fulfilling other inclusion criteria were included in the study. Data regarding their demographic profile and potential risk factors was collected on a well structured proforma, cases were followed until discharge or expiry. Data was analyzed using frequencies, proportions, group means, median and standard deviations. Results: The male to female ratio in our study was 1.2:1, with kerosene (50%) being the most common household agent followed by medicines (38%), insecticides (7%) and bathroom cleaners (5%). Factors such as mother's education level, number of siblings and storage place of poison correlated significantly with the cases of accidental poisoning. Most of the children (70%) presented within 3 hours of ingestion. Dyspnea was the most common symptom observed. The mortality rate in our study was 3%. Conclusions: Children belonging to age group 2-3 years are the most susceptible both in terms of morbidity and mortality. Preventive strategies need to be adopted at a national level to spread awareness among parents. [ABSTRACT FROM AUTHOR]

The article presents a diagram which shows the chemical structure of one-pot three-component synthesis of quinazolines.

5-Aryl-1 H -tetrazoles ( 1 – 24 ) were synthesized and screened for their xanthine oxidase (XO) inhibitory activity using allopurinol as standard inhibitor (IC 50  = 2.0 ± 0.01 µM). Six compounds 3 , 4 , 5 , 9 , 21 , and 24 exhibited significant to weak activities with IC 50 values in the range of 7.4–174.2 µM. Active compounds were further subjected to kinetic and molecular docking studies to deduce their modes of inhibition, and to study their interactions with the protein (XO) at atomic level, respectively. Interestingly, all these compounds showed a competitive mode of inhibition. Docking studies identified several important interactions between the ligand and the receptor protein (XO). Some of these interactions were similar to that exhibited by clinical inhibitors of XO (allopurinol, and febuxostat). This study identifies 5-aryl-1 H -tetrazoles as a new class of xanthine oxidase inhibitors, which deserves to be further, investigated for the treatment of hyperuricemia and gout. [ABSTRACT FROM AUTHOR]

Coumarin sulfonates 4 – 43 were synthesized by reacting 3-hydroxy coumarin 1 , 4-hydroxy coumarin 2 and 6-hydroxy coumarin 3 with different substituted sulfonyl chlorides and subjected to evaluate for their in vitro immunomodulatory potential. The compounds were investigated for their effect on oxidative burst activity of zymosan stimulated whole blood phagocytes using a luminol enhanced chemiluminescence technique. Ibuprofen was used as standard drug (IC 50 = 54.2 ± 9.2 μM). Eleven compounds 6 (IC 50 = 46.60 ± 14.6 μM), 8 (IC 50 = 11.50 ± 6.5 μM), 15 (IC 50 = 21.40 ± 12.2 μM), 19 (IC 50 = 5.75 ± 0.86 μM), 22 (IC 50 = 10.27 ± 1.06 μM), 23 (IC 50 = 33.09 ± 5.61 μM), 24 (IC 50 = 4.93 ± 0.58 μM), 25 (IC 50 = 21.96 ± 14.74 μM), 29 (IC 50 = 12.47 ± 9.2 μM), 35 (IC 50 = 20.20 ± 13.4 μM) and 37 (IC 50 = 14.47 ± 5.02 μM) out of forty demonstrated their potential suppressive effect on production of reactive oxygen species (ROS) as compared to ibuprofen. All the synthetic derivatives 4 – 43 were characterized by different available spectroscopic techniques such as 1 H NMR, 13 C NMR, EIMS and HRMS. CHN analysis was also performed. [ABSTRACT FROM AUTHOR]

Twenty derivatives of 5-aryl-2-(6′-nitrobenzofuran-2′-yl)-1,3,4-oxadiazoles ( 1 – 20 ) were synthesized and evaluated for their α -glucosidase inhibitory activities. Compounds containing hydroxyl and halogens ( 1 – 6 , and 8 – 18 ) were found to be five to seventy folds more active with IC 50 values in the range of 12.75 ± 0.10–162.05 ± 1.65 μM, in comparison with the standard drug, acarbose (IC 50 = 856.45 ± 5.60 μM). Current study explores the α -glucosidase inhibition of a hybrid class of compounds of oxadiazole and benzofurans. These findings may invite researchers to work in the area of treatment of hyperglycemia. Docking studies showed that most compounds are interacting with important amino acids Glu 276, Asp 214 and Phe 177 through hydrogen bonds and arene-arene interaction. [ABSTRACT FROM AUTHOR]

Benzimidazole analogs 1 – 27 were synthesized, characterized by EI-MS and 1 H NMR and their α -glucosidase inhibitory activities were found out experimentally. Compound 25 , 19 , 10 and 20 have best inhibitory activities with IC 50 values 5.30 ± 0.10, 16.10 ± 0.10, 25.36 ± 0.14 and 29.75 ± 0.19 respectively against α -glucosidase. Compound 6 and 12 has no inhibitory activity against α -glucosidase enzyme among the series. Further studies showed that the compounds are not showing any cytotoxicity effect. The docking studies of the compounds as well as the experimental activities of the compounds correlated well. From the molecular docking studies, it was observed that the top ranked conformation of all the compounds fit well in the active site of the homology model of α -glucosidase. [ABSTRACT FROM AUTHOR]

2-Indolcarbohydrazones 1 – 28 were synthesized and evaluated for their α -glucosidase inhibitory potential. A varying degree of inhibitory potential with IC 50 values in the range of 2.3 ± 0.11–226.4 ± 6.8 μM was observed while comparing these outcomes with the standard acarbose (IC 50 = 906.0 ± 6.3 μM). The stereochemistry of ten ( 10 ) randomly selected compounds ( 1 , 3 , 6 , 8 , 12 , 18 , 19 , 23 , 25 and 28 ) was predicted by Density Functional Theory (DFT). The stability of E isomer was deduced by comparing the calculated and experimental vibration modes of ν C O , ν N C and ν CH (CH in N CH -R). It was observed that except compound 18 , all other compounds were deduced to have E configuration while molecular modeling studies revealed the key interactions between enzyme and synthesized compounds. [ABSTRACT FROM AUTHOR]

• Quinazolinones inhibited the viability of Acanthamoeba castellanii. • NADPH-cytochrome c reductase is altered by these quinazolinones. • Quinazolinone compounds showed strong binding ability with AcCYP51. • Quinazolinone compounds exhibited wound healing in HaCaT cells. Acanthamoeba spp. are free living amoebae which can give rise to Acanthamoeba keratitis and granulomatous amoebic encephalitis. The surface of Acanthamoeba contains ergosterol which is an important target for drug development against eukaryotic microorganisms. A library of ten functionally diverse quinazolinone derivatives (Q1 – Q10) were synthesised to assess their activity against Acanthamoeba castellanii T4. The in-vitro effectiveness of these quinazolinones were investigated against Acanthamoeba castellanii by amoebicidal, excystation, host cell cytopathogenicity, and NADPH-cytochrome c reductase assays. Furthermore, wound healing capability was assessed at different time durations. Maximum inhibition at 50 μg/mL was recorded for compounds Q5, Q6 and Q8 , while the compound Q3 did not exhibit amoebicidal effects at tested concentrations. Moreover, LDH assay was conducted to assess the cytotoxicity of quinazolinones against HaCaT cell line. The results of wound healing assay revealed that all compounds are not cytotoxic and are likely to promote wound healing at 10 μg/mL. The excystation assays revealed that these compounds significantly inhibit the morphological transformation of A. castellanii. Compound Q3, Q7 and Q8 elevated the level of NADPH-cytochrome c reductase up to five folds. Sterol 14alpha-demethylase (CYP51) a reference enzyme in ergosterol pathway was used as a potential target for anti-amoebic drugs. In this study using i-Tasser, the protein structure of Acanthamoeba castellanii (AcCYP51) was developed in comparison with Naegleria fowleri protein (NfCYP51) structure. The sequence alignment of both proteins has shown 42.72% identity. Compounds Q1 - Q10 were then molecularly docked with the predicted AcCYP51. Out of ten quinazolinones, three compounds (Q3, Q7 and Q8) showed good binding activity within 3 Å of TYR 114. The in-silico study confirmed that these compounds are the inhibitor of CYP51 target site. This report presents several potential lead compounds belonging to quinazolinone derivatives for drug discovery against Acanthamoeba infections. [Display omitted] [ABSTRACT FROM AUTHOR]

Vitamin D is a lipid-soluble compound that plays a key role in bone mineral metabolism. The commercial current kits and several published assay methods (High-performance liquid chromatography (HPLC) and Immunoassay) are complicated due to the use of multiple reagents, larger sample volume, high backpressure, longer extraction time, evaporation under nitrogen after extraction, significant interference and antibody cross-reactivity. Here we report a new HPLC method for the determination of 25-hydroxyvitamin D2 (25-OHD2) and 25-hydroxyvitamin D3 (25-OHD3) that is simple (no evaporation), rapid (10-minute run time) and robust. Serum sample (300 μl) is mixed with 300 μl acetonitrile containing lauraphenone as internal standard. After vortexing and centrifugation, the supernatant was loaded into C18 extraction cartridges, washed with 70% methanol and then eluted with 200 μl of a mixture of 70% ethanol and 30% isopropyl alcohol (IPA). The eluent was mixed with 50 μl of water and injected into the HPLC-UV system for analysis. The method proved to be linear in the range of 10-750 nmol/L of 25-OHD2 and 25-OHD3. The intra- and inter-assay precision was less than 10 for both compounds at four different concentrations. The method was compared with (LC-MS/MS) and the correlation coefficients (R2) were 0.9454 and 0.9673 for 25-OHD2 and 25-OHD3 respectively. The proposed HPLC method is simple, rapid, robust and free from the most common problems encountered with commercial kits. It can be used in a high-volume laboratory that uses the HPLC method for the simultaneous determination of 25-OHD2 and 25-OHD3 in serum samples., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Diagnosis of Biotinidase deficiency (BTD) is extremely important to avoid several neurodevelopmental problems in early childhood. Colorimetric and fluorometric methods lack specificity and selectivity due to several interferences resulting in a high number of false positive results. We developed an HPLC method for BTD activity in serum with fluorescent detection. In colorimetric assays, biotinidase attacks the amide linkage of the artificial substrate biotinidyl-4-aminobenzoic acid (B-PABA) and releases p -aminobenzoic acid (PABA), which is converted to a purple dye by diazotization reaction. The newly developed method injects the reaction mixture directly into the HPLC column and quantifies using a six-point calibration curve without coupling and diazotization reaction. The method is linear over the 5-1000 μmol/L range. The detection and quantitation limits were 2.5 μmol/L and 5.0 μmol/L, respectively. When compared with colorimetric assay, the correlation coefficient (R 2 ) was 0.9963. The within-assay and between-assay precision was <10.0% for four levels of quality control samples. No significant variation in BTD activity was detected due to hemolysis, icteric, and lipemic samples. The newly developed method eliminates the potential interference due to the presence of aromatic amines and significantly reduces the false positive results observed with the colorimetric method. It is simple, specific, sensitive, faster in sample preparation, and requires a small sample volume. The newly developed HPLC method was used in our laboratory as a secondary tier test for initial positive BTD samples from newborn screening programs. To our knowledge, no similar HPLC method has been reported to date., Competing Interests: None., (© 2023 The Authors. Published by Elsevier Inc.)

Background: Hyperuricemia is associated with several disease conditions, such as atherosclerosis, arthritis, kidney stones, and many others. Xanthine oxidase (XO) is an enzyme that catalyzes the conversion of xanthine to uric acid. Hence, XO is a major therapeutic drug target in the treatment of hyperuricemia and associated disorders., Objectives: The current study aimed to identify XO inhibitors based on quinazoline derivatives, with the potential to be used against gout and other hyperuricemia-associated diseases., Methods: In the current study, eighteen quinazoline derivatives 2-19 were synthesized and assessed for their in vitro xanthine Oxidase (XO) inhibitory activity. Furthermore, the most active compounds, 5 and 17, were subjected to kinetics studies, followed by computational docking. Human BJ fibroblast cells were used to measure the cytotoxicity of active compounds., Results: Compounds 4-6, 8, 10, 13, 15-17, and 19 were found active against XO, with an IC 50 values between 33.688 to 362.173μM. The obtained results showed that compounds 5 and 17 possess a significant xanthine oxidase inhibitory activity. The kinetics and molecular docking studies suggested that compounds 5 (IC 50 = 39.904 ± 0.21 μM) and 17 (IC 50 = 33.688 ± 0.30 μM) bind in the allosteric site of XO and exhibit a non-competitive type of inhibition. The molecular docking studies also predicted that the NH group of the pyrimidine ring binds with Ser344 residues of XO. Furthermore, all active compounds were non-cytotoxic on the human BJ fibroblasts cell line., Conclusion: This study identifies a series of quinazoline compounds as xanthine oxidase inhibitors, with the potential to be further investigated., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

A library of twenty-five derivatives of 2-substituted quinazolin-4(3H)-ones 1-25 was synthesized and evaluated against phosphodiesterase-I (PDE) and carbonic anhydrase-II (CA). Compounds 17 (IC50 = 210.7 ± 2.62 µM), 16 (IC50 = 301.6 ± 1.18 µM), and 13 (IC50 = 458.13 ± 3.60 µM), selectively exhibited PDE inhibition while compounds 22 (IC50 = 61.33 ± 2.38 µM), 1 (IC50 = 108.30 ± 0.93 µM), and 21 (IC50 = 191.93 ± 2.72 µM), discriminatingly exhibited CA inhibition as compared to standards EDTA (IC50 = 277.69 ± 2.52 µM) and acetazolamide (IC50 = 0.12 ± 0.03 µM), for PDE and CA inhibitions, respectively. However, compound 15 was found to be active against both enzymes with the IC50 values 344.33 ± 4.32 µM and 20.94 ± 0.58 µM, for PDE and CA inhibitions, respectively. Remaining compounds were found to be inactive against both the enzymes. Structure-activity relationship studies are discussed herein.

Twenty-three (23) derivatives of coumarin (5-27) were synthesized and screened for their in vitro β- glucuronidase (E. coli) inhibitory activities. Only three compounds, 7,8-dihydroxy-4-methyl-2H-chromen-2-one (9) (IC50 = 52.39 ± 1.85 µM), 3-chloro-6-hexyl-7-hydroxy-4-methyl-2H-chromen-2-one (18) (IC50 = 60.50 ± 0.87 µM), and 3,6- dichloro-7-hydroxy-4-methyl-2H-chromen-2-one (15) (IC50 = 380.26 ± 0.92 µM) displayed activities against β- glucuronidase as compared to standard D-saccharic acid 1,4-lactone (IC50 = 45.75 ± 2.16 µM). The results indicated that the activity of the synthetic coumarins depends upon the substituents present on the coumarin skeleton.

In the title mol-ecule, C16H14N4O4, the quinazoline ring is substanti-ally planar (r.m.s. deviation = 0.0129 Å) and forms a dihedral angle of 2.73 (8)° with the benzene ring. The conformation of the mol-ecule is stabilized by an intra-molecular C-H⋯N hydrogen bond. In the crystal, mol-ecules are linked into chains running parallel to the b axis by C-H⋯O hydrogen bonds. In addition, π-π stacking is observed between dimethoxy-substituted and nitro-substituted benzene rings, with centroid-centroid distances in the range 3.6438 (10)-3.7148 (10) Å.

The title mol-ecule, C10H10N4O2, is almost planar and adopts an E configuration of the azomethine [C=N = 1.298 (2) Å] double bond. The benzene ring is attached to an essentially planar (r.m.s. deviation = 0.0226 Å) amidine moiety (N=CN/Me2), the dihedral angle between the two mean planes being 18.42 (11)°. The cyano group lies in the plane of the benzene ring [the C and N atoms deviating by 0.030 (3) and 0.040 (3) Å, respectively], while the nitro group makes a dihedral angle 5.8 (3)° with the benzene ring. There are two distinct inter-molecular hydrogen bonds, C-H⋯O and C-H⋯N, that stabilize the crystal structure; the former inter-actions result in centrosymmetric dimers about inversion centers resulting in ten-membered rings, while the later give rise to chains of mol-ecules running parallel to the b axis.

The mol-ecule of the title compound, C14H11ClN2O2 adopts an E conformation of the azomethine double bond and the dihedral angle between the benzene rings is 38.96 (13)°. In the crystal, mol-ecules are linked by N-H⋯O and O-H⋯O (with the ketone O atom as acceptor) and C-H⋯O (with the hy-droxy O atom as acceptor) hydrogen bonds, forming a three-dimensional network.