Microtubules, composed of tubulin proteins, have a crucial role in various cellular processes, including cell cycle regulation. The dynamic instability of microtubules has been an attractive target for cancer therapy. This study investigated two potent anticancer drug candidates, homoisoflavane derivatives SH-19021 and SHA-035, and evaluated their potential as microtubule-targeting agents (MTAs) in human colorectal cancer cells. At early time points, both SH-19021 and SHA-035 induced G2/M phase arrest. They altered the expression of multiple cell cycle-related genes, notably downregulating tubulin mRNA levels, leading to reduced cell viability and apoptosis. To further explore their mechanism of action, we conducted in silico docking studies, which demonstrated the potential of SH-19021 and SHA-035 as tubulin inhibitors. Both compounds were shown to bind directly to tubulin proteins, inhibiting microtubule polymerization in vitro and disrupting microtubule structures in colorectal cancer cells. Additionally, SH-19021 exhibited antitumor activity in a mouse xenograft model implanted with HCT116 cells. These findings suggest that SH-19021 and SHA-035 are novel and potent microtubule destabilizers with promising potential for cancer treatment.

Cremastranone is a member of the homoisoflavanone family with anti-angiogenic activity in the eyes. SH-11037, a potent and selective synthetic homoisoflavonoid derived from cremastranone, was studied here for pharmacokinetics and metabolism characterization with a special focus on esterase-mediated hydrolysis. SH-11037 was shown to be converted rapidly and nearly completely to SH-11008 following an intravenous dose in mice. SH-11008 showed a high systemic clearance well exceeding the hepatic blood flow in mice. Neither SH-11037 nor SH-11008 were detected in plasma following oral administration of SH-11037 and SH-11008 in mice. Carboxylesterase was shown to be responsible for the rapid and quantitative hydrolysis of SH-11037 to SH-11008 in mouse plasma; the hydrolytic bioconversion was much slower in dog and human plasma, with butyrylcholinesterase and paraoxonase 1 likely being responsible. In vitro metabolism studies with liver S9 fractions suggested that SH-11008 was likely to have a high hepatic metabolic clearance with a predicted hepatic extraction ratio close to 1 in both mouse and human. In conclusion, SH-11037 and SH-11008 both appear to possess pharmacokinetic profiles suboptimal as a systemic agent. SH-11008 is suggested to possess a low potential for systemic toxicity suitable as a topical ocular therapeutic agent.

Activity of the heme synthesis enzyme ferrochelatase (FECH) is implicated in multiple diseases. In particular, it is a mediator of neovascularization in the eye and thus an appealing therapeutic target for preventing blindness. However, no drug-like direct FECH inhibitors are known. Here, we set out to identify small-molecule inhibitors of FECH as potential therapeutic leads using a high-throughput screening approach to identify potent inhibitors of FECH activity. A structure-activity relationship study of a class of triazolopyrimidinone hits yielded drug-like FECH inhibitors. These compounds inhibit FECH in cells, bind the active site in cocrystal structures, and are anti-angiogenic in multiple in vitro assays. One of these promising compounds was anti-angiogenic in vivo in a mouse model of choroidal neovascularization. This foundational work may be the basis for new therapeutic agents to combat not only ocular neovascularization but also other diseases characterized by FECH activity.

Homoisoflavonoids are in the subclass of the larger family of flavonoids but have one more alkyl carbon than flavonoids. Among them, 5,7,8-trioxygenated homoisoflavonoids have not been extensively studied for synthesis and biological evaluation. Our current objective is to synthesize 2 5,7,8-trioxygenated chroman-4-ones and 12 5,7,8-trioxygenated homoisoflavonoids that have been isolated from the plants Bellevalia eigii, Drimiopsis maculata, Ledebouria graminifolia, Eucomis autumnalis, Eucomis punctata, Eucomis pallidiflora, Chionodoxa luciliae, Muscari comosum, and Dracaena cochinchinensis. For this purpose, 1,3,4,5-tetramethoxybenzene and 4'-benzyloxy-2',3'-dimethoxy-6'-hydroxyacetophenone were used as starting materials. Asymmetric transfer hydrogenation using Noyori's Ru catalyst provided 5,7,8-trioxygenated-3-benzylchroman-4-ones with R-configuration in high yield and enantiomeric excess. By selective deprotection of homoisoflavonoids using BCl3, the total synthesis of natural products including 10 first syntheses and three asymmetric syntheses has been completed, and three isomers of the reported dracaeconolide B could be provided. Our research on 5,7,8-trioxygenated homoisoflavonoids would be useful for the synthesis of related natural products and pharmacological applications.

The objective of this study was to characterize pharmacokinetics and metabolism of (+/-)-cremastranone (CMT) in mouse. Plasma concentrations of CMT following a single oral dose (10 mg/kg) were all below quantitation limit throughout 24-h time course, indicating poor oral bioavailability. Its plasma levels declined rapidly, with a half-life (t(1/2)) of 1.5 +/- 0.3 min following a single intravenous dose (5 mg/kg). They were below the quantitation limit after 15 min post-dosing. CMT showed a high plasma clearance (CLp) of 7.73 +/- 3.09 L/h/kg. Consistently, CMT was metabolized rapidly, with a t(1/2) < 1 min when it was incubated with liver or intestine S9 fractions of mouse and human in the presence of cofactors for CYP450, uridine 5'-diphosphate (UDP)-glucuronosyltransferase (UGT), and sulfotransferase (ST). Further studies showed that CMT was metabolized by CYP450, UGT, and ST in vitro in liver S9 fractions of mouse and human, with UGT being the major enzyme responsible for its rapid metabolism. CMT was metabolized by UGT and ST in intestine S9 fractions of mouse and human. Mono-demethylated (M1), mono-glucuronide (M2), and mono-sulfate (M3 and M4) metabolites were tentatively identified in vitro. In conclusion, the pharmacokinetics of CMT is suboptimal as a systemic agent, especially as an oral therapy, due to its extensive metabolism. This report provides possible structural modifications to design CMT derivatives with better pharmacokinetic properties.

Neovascular eye diseases are a major cause of blindness. Excessive angiogenesis is a feature of several conditions, including wet age-related macular degeneration, proliferative diabetic retinopathy, and retinopathy of prematurity. Development of novel antiangiogenic small molecules for the treatment of neovascular eye disease is essential to provide new therapeutic leads for these diseases. We have previously reported the therapeutic potential of anti-angiogenic homoisoflavanone derivatives with efficacy in retinal and choroidal neovascularization models, although these are racemic compounds due to the C3-stereogenic center in the molecules. This work presents asymmetric synthesis and structural determination of anti-angiogenic homoisoflavanones and pharmacological characterization of the stereoisomers. We describe an enantioselective synthesis of homoisoflavanones by virtue of ruthenium-catalyzed asymmetric transfer hydrogenation accompanying dynamic kinetic resolution, providing a basis for the further development of these compounds into novel experimental therapeutics for neovascular eye diseases.

The standard-of-care therapeutics for the treatment of ocular neovascular diseases like wet age-related macular degeneration (AMD) are biologics targeting vascular endothelial growth factor signaling. There are currently no FDA approved small molecules for treating these blinding eye diseases. Therefore, therapeutic agents with novel mechanisms are critical to complement or combine with existing approaches. Here, we identified soluble epoxide hydrolase (sEH), a key enzyme for epoxy fatty acid metabolism, as a target of an antiangiogenic homoisoflavonoid, SH-11037. SH-11037 inhibits sEH in vitro and in vivo and docks to the substrate binding cleft in the sEH hydrolase domain. sEH levels and activity are up-regulated in the eyes of a choroidal neovascularization (CNV) mouse model. sEH is overexpressed in human wet AMD eyes, suggesting that sEH is relevant to neovascularization. Known sEH inhibitors delivered intraocularly suppressed CNV. Thus, by dissecting a bioactive compound's mechanism, we identified a new chemotype for sEH inhibition and characterized sEH as a target for blocking the CNV that underlies wet AMD.

A facile and practical approach for the synthesis of ethyl 2-(2,3,4-trimethoxy-6-octanoylphenyl)acetate, an antidiabetic octaketide analogue of cytosporone B, is described. Unlike known approaches for the synthesis of cytosporones and their analogues, the key step of the developed route is a Friedel–Crafts alkylation of 1-(3,4,5-trimethoxyphenyl)octan-1-one with ethyl chloro(methylthio)acetate, followed by desulfurization.

Ocular neovascularization underlies major blinding eye diseases such as “wet” age‐related macular degeneration (AMD). Despite the successes of treatments targeting the vascular endothelial growth factor (VEGF) pathway, resistant and refractory patient populations necessitate discovery of new therapeutic targets. Using a forward chemical genetic approach, we identified the heme synthesis enzyme ferrochelatase (FECH) as necessary for angiogenesis in vitro and in vivo . FECH is overexpressed in wet AMD eyes and murine choroidal neovascularization; siRNA knockdown of Fech or partial loss of enzymatic function in the Fech m1Pas mouse model reduces choroidal neovascularization. FECH depletion modulates endothelial nitric oxide synthase function and VEGF receptor 2 levels. FECH is inhibited by the oral antifungal drug griseofulvin, and this compound ameliorates choroidal neovascularization in mice when delivered intravitreally or orally. Thus, FECH inhibition could be used therapeutically to block ocular neovascularization.

A naturally occurring homoisoflavonoid, cremastranone (1) inhibited angiogenesis in vitro and in vivo. We developed an analogue SH-11037 (2) which is more potent than cremastranone in human retinal microvascular endothelial cells (HRECs) and blocks neovascularization in animal models. Despite their efficacy, the mechanism of these compounds is not yet fully known. In the course of building on a strong foundation of SAR and creating a novel chemical tool for target identification of homoisoflavonoid-binding proteins, various types of photoaffinity probes were designed and synthesized in which benzophenone and biotin were attached to homoisoflavanonoids using PEG linkers on either the C-3′ or C-7 position. Notably, the photoaffinity probes linking on the phenol group of the C-3′ position retain excellent activity of inhibiting retinal endothelial cell proliferation with up to 72nM of GI50.

Ocular neovascularisation underlies blinding eye diseases such as retinopathy of prematurity, proliferative diabetic retinopathy, and wet age-related macular degeneration. These diseases cause irreversible vision loss, and provide a significant health and economic burden. Biologics targeting vascular endothelial growth factor (VEGF) are the major approach for treatment. However, up to 30% of patients are non-responsive to these drugs and they are associated with ocular and systemic side effects. Therefore, there is a need for small molecule ocular angiogenesis inhibitors to complement existing therapies. We examined the safety and therapeutic potential of SH-11037, a synthetic derivative of the antiangiogenic homoisoflavonoid cremastranone, in models of ocular neovascularisation. SH-11037 dose-dependently suppressed angiogenesis in the choroidal sprouting assay ex vivo and inhibited ocular developmental angiogenesis in zebrafish larvae. Additionally, intravitreal SH-11037 (1 μM) significantly reduced choroidal neovascularisation (CNV) lesion volume in the laser-induced CNV mouse model, comparable to an anti-VEGF antibody. Moreover, SH-11037 synergised with anti-VEGF treatments in vitro and in vivo . Up to 100 μM SH-11037 was not associated with signs of ocular toxicity and did not interfere with retinal function or pre-existing retinal vasculature. SH-11037 is thus a safe and effective treatment for murine ocular neovascularisation, worthy of further mechanistic and pharmacokinetic evaluation.

Synthesis and biological evaluation of novel homoisoflavonoids for retinal neovascularization

ChemInformVolume 46, Issue 12 Natural Products ChemInform Abstract: The First Synthesis of the Antiangiogenic Homoisoflavanone, Cremastranone. Bit Lee, Bit Lee Coll. Pharm., Gachon Univ., Incheon 406-799, S. KoreaSearch for more papers by this authorHalesha D. Basavarajappa, Halesha D. Basavarajappa Coll. Pharm., Gachon Univ., Incheon 406-799, S. KoreaSearch for more papers by this authorRania S. Sulaiman, Rania S. Sulaiman Coll. Pharm., Gachon Univ., Incheon 406-799, S. KoreaSearch for more papers by this authorXiang Fei, Xiang Fei Coll. Pharm., Gachon Univ., Incheon 406-799, S. KoreaSearch for more papers by this authorSeung-Yong Seo, Seung-Yong Seo Coll. Pharm., Gachon Univ., Incheon 406-799, S. KoreaSearch for more papers by this authorTimothy W. Corson, Timothy W. Corson Coll. Pharm., Gachon Univ., Incheon 406-799, S. KoreaSearch for more papers by this author Bit Lee, Bit Lee Coll. Pharm., Gachon Univ., Incheon 406-799, S. KoreaSearch for more papers by this authorHalesha D. Basavarajappa, Halesha D. Basavarajappa Coll. Pharm., Gachon Univ., Incheon 406-799, S. KoreaSearch for more papers by this authorRania S. Sulaiman, Rania S. Sulaiman Coll. Pharm., Gachon Univ., Incheon 406-799, S. KoreaSearch for more papers by this authorXiang Fei, Xiang Fei Coll. Pharm., Gachon Univ., Incheon 406-799, S. KoreaSearch for more papers by this authorSeung-Yong Seo, Seung-Yong Seo Coll. Pharm., Gachon Univ., Incheon 406-799, S. KoreaSearch for more papers by this authorTimothy W. Corson, Timothy W. Corson Coll. Pharm., Gachon Univ., Incheon 406-799, S. KoreaSearch for more papers by this author First published: 05 March 2015 https://doi.org/10.1002/chin.201512285Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume46, Issue12March, 2015 RelatedInformation

Eye diseases characterized by excessive angiogenesis such as wet age-related macular degeneration, proliferative diabetic retinopathy, and retinopathy of prematurity are major causes of blindness. Cremastranone is an antiangiogenic, naturally occurring homoisoflavanone with efficacy in retinal and choroidal neovascularization models and antiproliferative selectivity for endothelial cells over other cell types. We undertook a cell-based structure-activity relationship study to develop more potent cremastranone analogues, with improved antiproliferative selectivity for retinal endothelial cells. Phenylalanyl-incorporated homoisoflavonoids showed improved activity and remarkable selectivity for retinal microvascular endothelial cells. A lead compound inhibited angiogenesis in vitro without inducing apoptosis and had efficacy in the oxygen-induced retinopathy model in vivo.