The anti-obesity potential of sigmoidin A

Context: During the last few decades, the prevalence of obesity in the western world has dramatically increased with epidemic proportions. Hand in hand with this statistic, the incidences of obesity-linked diseases such as diabetes are increasing with pandemic rate. The search for novel drugs and nutritional intervention approaches for obesity is now of significant importance.

Objective: The anti-obesity potential of eriodictyol (ERD) and its close structural analogue, sigmoidin A (SGN), were evaluated. SGN was isolated from Erythrina abyssinica Lam. ex DC. (Fabaceae).

Materials and methods: Concentrations between 300 and 0.1 µM of test samples and reference drugs made in three-fold dilutions were tested for enzyme inhibitory effects. The major obesity target, pancreatic lipase, was used to test the anti-obesity potential while the selective effects of the compounds were determined through assessments of effects on α-glucosidase.

Results: The inhibitory effect of SGN on pancreatic lipase (IC₅₀, 4.5 ± 0.87 µM) was 30-times greater than that of ERD (IC₅₀, 134 ± 19.39 µM) while their effect on α-glucosidase enzyme was comparable (IC₅₀ value of 62.5 ± 9.47 and 57.5 ± 13.15 µM). The anti-obesity drug, orlistat, inhibited pancreatic lipase with an IC₅₀ value of 0.3 ± 0.04 µM, while the anti-diabetic drug, acarbose, inhibited α-glucosidase with an IC₅₀ value of 190.6 ± 16.05 µM.

Discussion: Although less active than the standard anti-obesity drug, orlistat, the observed activity indicated that prenylation of the flavonoid skeleton potently enhances anti-lipase activity.

Conclusion: Such groups of flavonoids need to be further investigated for their therapeutic and nutritional benefit in combating obesity problems.     

Design,synthesis, biological evaluation,and molecular modeling studies of rhodanine derivatives as pancreatic lipase inhibitors

A series of rhodanine‐3‐acetic acid derivatives were synthesized via Knoevenagel condensation of rhodanine‐3‐acetic acid with various substituted aromatic aldehydes. The synthesized derivatives were screened in vitro for understanding the inhibitory potential towards pancreatic lipase (PL), a key enzyme responsible for the digestion of dietary fats. Derivative 8f exhibited a potential inhibitory activity towards PL (IC₅₀ = 5.16 µM), comparable to that of the standard drug, orlistat (0.99 µM). An increase in the density of the aromatic ring resulted in potential PL inhibition. The enzyme kinetics of 8f exhibited a reversible competitive‐type inhibition, similar to that of orlistat. Derivative 8f exhibited a MolDock score of ‐125.19 kcal/mol in docking studies, and the results were in accordance with their PL inhibitory potential. Furthermore, the reactive carbonyl group of 8f existed at a distance adjacent to Ser152 (≈3 Å) similar to that of orlistat. Molecular dynamics simulation (10 ns) of the 8f ‐PL complex revealed a stable binding conformation of 8f in the active site of PL (maximum root mean square displacement of ≈2.25 Å). The present study identified novel rhodanine‐3‐acetic acid derivatives with promising PL inhibitory potential, and further lead optimization might result in potent PL inhibitors.     

Further brominated polyacetylenes with pancreatic lipase inhibitory activity from Chinese marine sponge Xestospongia testudinaria

A new brominated polyacetylene, xestonariene I (1), along with three known related analogues (2–4), was obtained from Chinese marine sponge Xestospongia testudinaria. Its structure was determined on the basis of detailed spectroscopic analysis and by comparison with literature data. Compound 4 exhibited significant inhibitory activity against pancreatic lipase, which plays a key role in preventing obesity, with an IC₅₀ value of 0.61 μM, being comparable to that of the positive control orlistat (IC₅₀ = 0.78 μM).     

Synthesis,cytotoxicity, and molecular docking of substituted 3-(2-methylbenzofuran-3-yl)-5-(phenoxymethyl)-1,2,4-oxadiazoles

A series of new benzofuran/oxadiazole hybrids ( 8a – n ) was synthesized from 2H-chromene-3-carbonitriles ( 3a – c ) through the multistep synthetic methodology, and these hybrids are known to exhibit anticancer activities. All the compounds were evaluated for their in vitro cytotoxicity against the HCT116 and MIA PaCa2 cell lines. Compounds 6a (IC₅₀: 9.71 ± 1.9 μM), 6b (IC₅₀: 7.48 ± 0.6 μM), and 6c (IC₅₀: 3.27 ± 1.1 μM) displayed a significant cytotoxic activity, whereas compounds 8d and 8e exhibited good activity against both cell lines. The depletion of glycogen synthase kinase-3β (GSK3β) induces apoptosis through the inhibition of basal NF-κB activity in HCT116 colon cancer cells and MIA PaCa2 pancreatic cancer cells. Molecular docking of compounds 6a , 6b , 6c , 8d , and 8e with GSK3β demonstrated the best binding affinity, correlating with the biological activity assay. Furthermore, the structure–activity relationship of these novel compounds reveals promising features for their use in anticancer therapy.     

The application of tandem aza-wittig reaction to synthesize artemisinin-guanidine hybrids and their anti-tumor activity

Three series of novel artemisinin–guanidine hybrids 4a–4f , 8a–8h and 9a–9h have been facilely synthesized via four‐component reaction (aza‐Wittig reaction) and evaluated for their anti‐tumor activities against A549, HT‐29 and MDA‐MB‐231 cell lines in vitro. All of the tested compounds showed enhanced anti‐tumor activities with IC₅₀ values ranging from 0.02 µM to 12.0 µM as compared to DHA (dihydroartemisinin). Among them, artemisinin derived dimers, compounds 9b (IC₅₀ = 0.05 µM), 9d (IC₅₀ = 0.06 µM) and 9f (IC₅₀ = 0.02 µM) were found to be most active against HT29 cells.     

Xanthine oxidase/tyrosinase inhibiting,antioxidant, and antifungal oxindole alkaloids from Isatis costata

Phytochemical investigations on the ethyl acetate soluble fraction of the whole plant of Isatis costata Linn. (Brassicaseae) led to the isolation of the oxindole alkaloids costinones A (1), B (2), isatinones A (3), B (4), indirubin (5), and trisindoline (6). Compounds 1–6 displayed significant to moderate inhibition against xanthine oxidase enzyme with IC₅₀ values ranging from 90.3?±?0.06 to 179.6?±?0.04 µM, whereas the standard inhibitor of xanthine oxidase (allopurinol) had an IC₅₀ value of 7.4?±?0.07 µM. Compounds 1 (IC₅₀ 7.21?±?0.05 µM), 2 (IC₅₀ 9.40?±?0.03 µM), 3 (IC₅₀ 11.51?±?0.07 µM), 4 (IC₅₀ 12.53?±?0.06 µM), 5 (IC₅₀ 14.29?±?0.09 µM), and 6 (IC₅₀ 17.34?±?0.04 µM) exhibited pronounced activities when compared with the standard tyrosinase inhibitor l-mimosine (IC₅₀ 3.70?±?0.03 µM), along with DPPH radical scavenging activity with IC₅₀ 226, 270, 300, 320, 401, and 431 µM, respectively. The crude extract and compounds 1, 2, 5, and 6 showed significant antifungal activity against Trichophyton schoen leinii, Aspergillus niger, Candida albicans, Trichophyton simii, and Macrophomina phaseolina.     

Synthesis and cytotoxic evaluation of some new phthalazinylpiperazine derivatives

A new series of 1,4‐disubstituted phthalazinylpiperazine derivatives 7a–f , 12a–f and 20a–f were designed and synthesized in order to develop potent and selective antitumor agents. The target compounds were screened for their cytotoxic activities against A549, HT‐29 and MDA‐MB‐231 cancer cell lines in vitro. Among them, compounds 7a–f exhibited excellent selectivity for MDA‐MB‐231 with IC₅₀ values ranging from 0.013 µM to 0.079 µM. The most promising compound, 7e (IC₅₀ = 2.19 µM, 2.19 µM, 0.013 µM), was 9.3, 10, and 4.9 × 10³ times more active than vatalanib (IC₅₀ = 20.27 µM, 21.96 µM, 63.90 µM), respectively.     

Design,synthesis, molecular docking,and anticancer evaluations of 1-benzylquinazoline-2,4(1H,3H)-dione bearing different moieties as VEGFR-2 inhibitors

A novel series of 1-benzylquinazoline-2,4(1H,3H)-dione derivatives, 6a , b to 11a – e , was designed, synthesized, and evaluated for their anticancer activity against HepG2, HCT-116, and MCF-7 cells. Compounds 11b , 11e , and 11c were found to be the most potent derivatives of all tested compounds against the HepG2, HCT-116, and MCF-7 cancer cell lines, with GI₅₀ = 9.16 ± 0.8, 5.69 ± 0.4, 5.27 ± 0.2 µM, 9.32 ± 0.9, 6.37 ± 0.7, 5.67 ± 0.5 µM, and 9.39 ± 0.5, 6.87 ± 0.7, 5.80 ± 0.4 µM, respectively. These compounds exhibited nearly the same activity as sorafenib against HepG2 and HCT-116 cells and a higher activity against MCF-7 cells (GI₅₀ = 9.18 ± 0.6, 5.47 ± 0.3, and 7.26 ± 0.3 µM, respectively). Also, these compounds displayed a lower activity than doxorubicin against HepG2 cells and a higher activity against HCT-116 and MCF-7 cells (GI₅₀ = 7.94 ± 0.6, 8.07 ± 0.8, and 6.75 ± 0.4 µM, respectively). The most active antiproliferative derivatives, 6a , b , 8 , 9 , and 11a – e , were selected to evaluate their enzymatic inhibitory activity against VEGFR-2. Compounds 11b , 11e , and 11c potently inhibited VEGFR-2 at IC₅₀ values of 0.12 ± 0.02, 0.12 ± 0.02, and 0.13 ± 0.02 µM, respectively, which are nearly equipotent as sorafenib IC₅₀ value (0.10 ± 0.02 µM). Furthermore, molecular docking studies were performed for all synthesized compounds to assess their binding pattern and affinity toward the VEGFR-2 active site.     

Design,synthesis, docking,and anticancer evaluations of phthalazines as VEGFR-2 inhibitors

Twenty new N-substituted-4-phenylphthalazin-1-amine derivatives were designed, synthesized, and evaluated for their anticancer activities against HepG2, HCT-116, and MCF-7 cells as VEGFR-2 inhibitors. HCT-116 was the most sensitive cell line to the influence of the new derivatives. In particular, compound 7f was found to be the most potent derivative among all the tested compounds against the three cancer cell lines, with 50% inhibition concentration, IC₅₀ = 3.97, 4.83, and 4.58 µM, respectively, which is more potent than both sorafenib (IC₅₀ = 9.18, 5.47, and 7.26 µM, respectively) and doxorubicin (IC₅₀ = 7.94, 8.07, and 6.75 µM, respectively). Fifteen of the synthesized derivatives were selected to evaluate their inhibitory activities against VEGFR-2. Compound 7f was found to be the most potent derivative that inhibited VEGFR-2 at an IC₅₀ value of 0.08 µM, which is more potent than sorafenib (IC₅₀ = 0.10 µM). Compound 8c inhibited VEGFR-2 at an IC₅₀ value of 0.10 µM, which is equipotent to sorafenib. Moreover, compound 7a showed very good activity with IC₅₀ values of 0.11 µM, which is nearly equipotent to sorafenib. In addition, compounds 7d , 7c , and 7g possessed very good VEGFR-2-inhibitory activity, with IC₅₀ values of 0.14, 0.17, and 0.23 µM, respectively.     

Synthesis and Antitumor Activity of Novel Nitrogen Mustard‐Linked Chalcones

A series of nitrogen mustard‐linked chalcones were synthesized and evaluated for their antitumor activity in vitro against the K562 and HepG2 cell lines. The aldol condensation of [N,N‐bis(chloroethyl)‐3‐amino]‐acetophenone ( 2 ) with aromatic aldehydes afforded the nitrogen mustard‐linked chalcones. Among the analogs tested, compounds 5e and 5k exhibited significant anti‐proliferation activities against K562 cells with IC₅₀ values of 2.55 and 0.61 µM, respectively, which revealed higher cell toxicity than the standard drugs cisplatin (IC₅₀ > 200 µM) and adriamycin (IC₅₀ = 14.88 µM). The methoxyl and N,N‐dimethyl groups on the B‐ring of the chalcone frame enhanced the inhibitory activities against both the K562 and HepG2 cell lines. The structure–activity relationship study indicated that the inhibitory activities significantly varied with the position(s) and species of the substituted group(s).     

5-(4-Methoxybenzylidene)thiazolidine-2,4-dione-derived VEGFR-2 inhibitors: Design,synthesis, molecular docking,and anticancer evaluations

A novel series of 5-(4-methoxybenzylidene)thiazolidine-2,4-dione derivatives, 5a–g and 7a–f , was designed, synthesized, and evaluated for their anticancer activity against HepG2, HCT116, and MCF-7 cells. HepG2 and HCT116 were the most sensitive cell lines to the influence of the new derivatives. In particular, compounds 7f , 7e , 7d , and 7c were found to be the most potent derivatives of all the tested compounds against the HepG2, HCT116, and MCF-7 cancer cell lines. Compound 7f (IC₅₀ = 6.19 ± 0.5, 5.47 ± 0.3, and 7.26 ± 0.3 µM, respectively) exhibited a higher activity than sorafenib (IC₅₀ = 9.18 ± 0.6, 8.37 ± 0.7, and 5.10 ± 0.4 µM, respectively) against HepG2 and MCF-7, cells but a lower activity against HCT116 cancer cells, respectively. Also, this compound displayed a higher activity than doxorubicin (IC₅₀ = 7.94 ± 0.6, 8.07 ± 0.8, and 6.75 ± 0.4 µM, respectively) against HepG2 and MCF-7 cells, but nearly the same activity against HCT116 cells, respectively. All derivatives, 5a–g and 7a–f , were evaluated for their inhibitory activities against vascular endothelial growth factor receptor-2 (VEGFR-2). Among them, compound 7f was found to be the most potent derivative that inhibited VEGFR-2 at an IC₅₀ value of 0.12 ± 0.02 µM, which is nearly the same as that of sorafenib (IC₅₀ = 0.10 ± 0.02 µM). Compounds 7e , 7d , 7c , and 7b exhibited the highest activity, with IC₅₀ values of 0.13 ± 0.02, 0.14 ± 0.02, 0.14 ± 0.02, and 0.18 ± 0.03 µM, respectively, which are more than the half of that of sorafenib. Furthermore, molecular docking was performed to investigate their binding mode and affinities toward the VEGFR-2 receptor. The data obtained from the docking studies highly correlated with those obtained from the biological screening.     

Dillapiole as Antileishmanial Agent: Discovery,Cytotoxic Activity and Preliminary SAR Studies of Dillapiole Analogues

In this paper, the isolation of dillapiole ( 1 ) from Piper aduncum was reported as well as the semi‐synthesis of two phenylpropanoid derivatives [di‐hydrodillapiole ( 2 ), isodillapiole ( 3 )], via reduction and isomerization reactions. Also, the compounds' molecular properties (structural, electronic, hydrophobic, and steric) were calculated and investigated to establish some preliminary structure–activity relationships (SAR). Compounds were evaluated for in vitro antileishmanial activity and cytotoxic effects on fibroblast cells. Compound 1 presented inhibitory activity against Leishmania amazonensis (IC₅₀ = 69.3 µM) and Leishmania brasiliensis (IC₅₀ = 59.4 µM) and induced cytotoxic effects on fibroblast cells mainly in high concentrations. Compounds 2 (IC₅₀ = 99.9 µM for L. amazonensis and IC₅₀ = 90.5 µM for L. braziliensis) and 3 (IC₅₀ = 122.9 µM for L. amazonensis and IC₅₀ = 109.8 µM for L. brasiliensis) were less active than dillapiole ( 1 ). Regarding the molecular properties, the conformational arrangement of the side chain, electronic features, and the hydrophilic/hydrophobic balance seem to be relevant for explaining the antileishmanial activity of dillapiole and its analogues.     

Benzoxazole/benzothiazole‐derived VEGFR‐2 inhibitors: Design,synthesis, molecular docking,and anticancer evaluations

A novel series of benzoxazole/benzothiazole derivatives 4a–c – 11a–e were designed, synthesized, and evaluated for anticancer activity against HepG2, HCT‐116, and MCF‐7 cells. HCT‐116 was the most sensitive cell line to the influence of the new derivatives. In particular, compound 4c was found to be the most potent derivative against HepG2, HCT‐116, and MCF‐7 cells, with IC₅₀ values = 9.45 ± 0.8, 5.76 ± 0.4, and 7.36 ± 0.5 µM, respectively. Compounds 4b, 9f , and 9c showed the highest anticancer activities against HepG2 cells with IC₅₀ values of 9.97 ± 0.8, 9.99 ± 0.8, and 11.02 ± 1.0 µM, respectively, HCT‐116 cells with IC₅₀ values of 6.99 ± 0.5, 7.44 ± 0.4, and 8.15 ± 0.8 µM, respectively, and MCF‐7 cells with IC₅₀ values of 7.89 ± 0.7, 8.24 ± 0.7, and 9.32 ± 0.7 µM, respectively, in comparison with sorafenib as reference drug with IC₅₀ values of 9.18 ± 0.6, 5.47 ± 0.3, and 7.26 ± 0.3 µM, respectively. The most active compounds 4a–c, 9b,c,e,f,h , and 11c,e were further evaluated for their VEGFR‐2 inhibition. Compounds 4c and 4b potently inhibited VEGFR‐2 at IC₅₀ values of 0.12 ± 0.01 and 0.13 ± 0.02 µM, respectively, which are nearly equipotent to the sorafenib IC₅₀ value (0.10 ± 0.02 µM). Furthermore, molecular docking studies were performed for all synthesized compounds to assess their binding pattern and affinity toward the VEGFR‐2 active site.     

Synthesis and evaluation as PDE4 inhibitors of pyrimidine‐2,4‐dione derivatives

A series of nitraquazone analogs with a pyrimidindione core was synthesized and tested for inhibitory activity on PDE4, selectivity versus PDE3 and PDE5 and for affinity towards the rolipram high‐affinity binding site (HARBS). The 5‐anilino derivatives 13–18 showed the best profile combining appreciable PDE4 inhibitory activity (IC₅₀ = 5–14 µM) with a good selectivity toward PDE3 and PDE5. The same compounds demonstrate low affinity for the HARBS site with IC₅₀ values of 12–69 µM (IC₅₀ for Rolipram = 3.6 nM). Drug Dev Res 72: 274–288, 2011. © 2010 Wiley‐Liss, Inc.     

Anti-tumor activity of new artemisinin-chalcone hybrids

In an attempt to develop potent and selective anti‐tumor agents, three new series of artemisinin–chalcone hybrids 10a – 10g , 11a – 11g and 12a–12h were designed, synthesized and screened for their anti‐tumor activity against five cell lines (HT‐29, A549, MDA‐MB‐231, HeLa and H460) in vitro. Among compounds 10a–g and 11a–11g , most of them displayed enhanced activity and good selectivity toward HT‐29 and HeLa cell lines with IC₅₀ values ranging from 0.12 to 0.85 µM as compared with DHA (dihydroartemisinin). Compounds 10a and 11a are most active toward HeLa cells with IC₅₀ values of 0.12 and 0.19 µM. The results revealed that the presence of chalcone moiety is beneficial to their activity and selectivity. In addition, compounds 12a ‐ 12h containing a ‘reversed chalcone’ moiety showed only slight improvement in activity than those of DHA.     

Synthesis of new arylazopyrazoles as apoptosis inducers: Candidates to inhibit proliferation of MCF‐7 cells

New 4‐arylazo‐3,5‐diamino‐1H‐pyrazole derivatives substituted in the 4‐aryl ring with the acetyl moiety were designed and synthesized. The antiproliferative activity of the novel arylazopyrazoles was examined against the MCF‐7 cell line. Among all target compounds, 8b (IC₅₀ 3.0 µM) and 8f (IC₅₀ 4.0 µM) displayed higher cytotoxicity as compared with the reference standard imatinib (IC₅₀ 7.0 µM). Further studies to explore the mechanism of action were performed on the most active hit of our library, 8b , via anti‐CDK2 kinase activity. It demonstrated good inhibitory effects for CDK2 (IC₅₀ 0.24 µM) with 62.5% inhibition, compared with imatinib. The cell cycle analysis in the MCF‐7 cell line revealed apoptosis induction by 8b and cell cycle arrest at the S phase. Docking in the CDK2 active site and pharmacophore modeling confirmed the affinity of 8b to the CDK2 active site. Absorption, distribution, metabolism, and excretion studies revealed that our target compounds are orally bioavailable, with no permeation through the blood–brain barrier.     

2-(2′-Pyridyl) benzimidazole derivatives and their urease inhibitory activity

Pyridyl-benzimidazole analogues 1–11 with variable substituent on phenyl ring of phenacyl moiety were synthesized and evaluated for their urease inhibitory activity. The compounds exhibited urease inhibition with IC₅₀ between 19.22 and 77.31 µM. Compounds 4 (IC₅₀ = 19.22 ± 0.49 µM) showed a urease inhibition comparable to thiourea (IC₅₀ = 21.00 ± 0.01 µM) and twofold more active than acetohydroxamic acid (IC₅₀ = 42.00 ± 1.26 µM) (standards), respectively. Moreover, compounds 5 (IC₅₀ = 21.55 ± 0.36 µM), 1 (IC₅₀ = 24.37 ± 0.41 µM), 7 (IC₅₀ = 25.44 ± 0.19 µM), 6 (IC₅₀ = 27.62 ± 0.25 µM), 3 (IC₅₀ = 31.32 ± 0.75 µM), 8 (40.88 ± 0.36 µM) and 9 (41.22 ± 0.42 µM) also exhibited excellent activities when compared to the standards. Compounds 2 (IC₅₀ = 65.46 ± 0.75 µM), 10 (68.99 ± 0.33 µM) and 11 (77.31 ± 0.51 µM) showed a moderate activity. The size of the substituents and their electron donating or withdrawing affects as well as their position on phenyl apparently modulates the enzyme inhibitory activity.     

Enantiospecific effects of chiral drugs on cytochrome P450 inhibition in vitro

1.?The aim of this work was to examine the differences in the inhibitory potency of individual enantiomers and racemic mixtures of selected chiral drugs on human liver microsomal cytochromes P450.

2.?The interaction of enantiomeric forms of six drugs (tamsulosin, tolterodine, citalopram, modafinil, zopiclone, ketoconazole) with nine cytochromes P450 (CYP3A4, CYP2E1, CYP2D6, CYP2C19, CYP2C9, CYP2C8, CYP2B6, CYP2A6, CYP1A2) was examined. HPLC methods were used to estimate the extent of the inhibition of specific activity in vitro.

3.?Tamsulosin (TAM) and tolterodine (TOL) inhibited CYP3A4 activity with an enantiospecific pattern. The inhibition of CYP3A4 activity differed for R-TAM (K_i 2.88?±?0.12?µM) and S-TAM (K_i 14.22?±?0.53?µM) as well as for S-TOL (K_i 1.71?±?0.03?µM) and R-TOL (K_i 4.78?±?0.17?µM). Also, the inhibition of CYP2C19 by ketoconazole (KET) cis-enantiomers exhibited enantioselective behavior: the (+)-KET (IC₅₀ 23.64?±?6.25?µM) was more potent than (?)-KET (IC₅₀ 66.12?±?12.6?µM). The inhibition of CYP2C19 by modafinil (MOD) enantiomers (R-MOD IC₅₀?=?51.79?±?8.58?µM, S-MOD IC₅₀?=?48.62?±?9.74?µM) and the inhibition of CYP2D6 by citalopram (CIT) enantiomers (R-CIT IC₅₀?=?68.17?±?5.70?µM, S-CIT IC₅₀?=?62.63?±?7.89?µM) was not enantiospecific.

4.?Although enantiospecific interactions were found (TAM, TOL, KET), they are probably not clinically relevant as the plasma levels are generally lower than the drug concentration needed for prominent inhibition (at least 50% of CYP activity).     

In vitro inhibition and induction of human cytochrome P450 enzymes by SIPI5357, a potential antidepressant

This study investigated the in vitro drug–drug interaction potential of SIPI5357, an arylalkanol‐piperazine derivative used in the treatment of depression. Drug–drug interaction occurs via inhibition or induction of enzymes involved in their metabolism. In human liver microsomes, SIPI5357 showed the strongest inhibition of CYP2D6, followed by CYP3A4 (testosterone) and CYP2C8. Inhibition was observed in a concentration‐dependent manner, with IC₅₀ values of 18.45 µM, 36.63 µM (CYP3A4/testosterone), 89.23 µM, respectively. SIPI5357 was predicted not to cause significant metabolic drug–drug interaction via inhibition of CYP1A2, CYP2C9, CYP2C19, CYP2E1 or CYP3A4 (midazolam) because the IC₅₀ values for these enzymes were both >100 µM (200 times maximum plasma concentration [C_max]). SIPI5357 showed a mixed model inhibition of CYP2D6 (K_i = 11.12 µM). The value of [I]/K_i for CYP2D6 inhibition by SIPI5357 is below the FDA cut‐off value of 0.1; it is therefore reasonable to assume that SIPI5357 will not cause significant CYP2D6 inhibition. However, positive controls (50 µM omeprazole and 25 µM rifampin) caused the anticipated CYP induction, but the highest concentration of SIPI5357 (5 µM; 10 times plasma C_max) had a minimal effect on CYP1A2 and CYP3A4 mRNA levels in freshly isolated human hepatocytes, suggesting that SIPI5357 is not an inducer of these enzymes. However, significant induction of CYP2B6 was observed at 0.5 µM and 5 µM. In conclusion, SIPI5357 might cause drug–drug interaction via induction of CYP2B6. The in vivo drug–drug interaction potential deserves further investigation. Copyright © 2015 John Wiley & Sons, Ltd.     

Synthesis and Evaluation of Benzophenone O‐Glycosides as α‐Glucosidase Inhibitors

The first total synthesis of benzophenone O‐glycosides (iriflophenone 2‐O‐α‐L ‐rhamnopyranoside: 1 and aquilarisinin: 2 ) isolated from the leaves of Aquilaria sinensis and related new derivatives ( 3 – 12 ) was accomplished through suitable protecting group manipulations and glycosylation starting from commercially available L ‐rhamnose, D ‐glucose, D ‐galactose, D ‐mannose, D ‐xylose, and 1,3,5‐trihydroxybenzene. All synthesized benzophenone O‐glycosides were evaluated for their inhibitory activities against α‐glucosidase. Of these, benzophenone O‐glycosides 4 and 10 exhibited the most potent inhibitory activity in vitro against α‐glucosidase with IC₅₀ values of 168.7 ± 13.9 and 210.1 ± 23.9 µM, respectively, when compared with that of the positive control acarbose with an IC₅₀ value of 569.3 ± 49.7 µM.