title: Curcumin and its carbocyclic analogs: structure-activity in relation to antioxidant and selected biological properties.
abstract: Curcumin is the major phenolic compound present in turmeric (Curcuma longa L.). Curcumin and 15 novel analogs were investigated for their antioxidant and selected biological activities. Strong relationships between the structure and evaluated activity revealed that the compounds with specific functional groups and carbon skeleton had specific biological profiles. Among the compounds tested, the derivatives (E)-2-(3,4-dimethoxybenzylidene)-5-((E)-3-(3,4-dimethoxyphenyl)acryloyl)cyclopentanone (3e), and (E)-2-(4-hydroxy-3-methoxybenzylidene)-5-((E)-3-(4-hydroxy-3-methoxyphenyl)acryloyl)-cyclopentanone (3d) and the parent compound curcumin exhibited the strongest free radical scavenging and antioxidant capacity. Concerning the other biological activities studied the compound (E)-2-(4-hydroxy-3-methoxybenzylidene)-5-((E)-3-(4-hydroxy-3-methoxy-phenyl)-acryloyl)cyclopentanone (3d) was the most potent angiotensin converting enzyme (ACE) inhibitor, while the derivatives (E)-2-(4-hydroxybenzylidene)-6-((E)-3-(4-hydroxyphenyl)acryloyl)cyclohexanone (2b), (E)-2-(3,4-dimethoxybenzylidene)-6-((E)-3-(3,4-dimethoxyphenyl)acryloyl)cyclohexanone (2e) and (E)-2-(3,4-dimethoxybenzylidene)-5-((E)-3-(3,4-dimethoxyphenyl)acryloyl)cyclopentanone (3e) exhibited strong tyrosinase inhibition. Moreover, (E)-2-(3,4-dimethoxybenzylidene)-6-((E)-3-(3,4-dimethoxyphenyl)-acryloyl)cyclohexanone (2e) was also found to be the strongest human HIV-1 protease inhibitor in vitro among the tested compounds. Cytotoxicity studies using normal human lung cells revealed that the novel curcumin as well as its carbocyclic analogs are not toxic.
authors.affiliation: Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia B2N 5E3, Canada.
authors.forename: Khushwant S
authors.initials: KS
authors.lastname: Bhullar
authors.forename: Amitabh
authors.initials: A
authors.lastname: Jha
authors.forename: Dani
authors.initials: D
authors.lastname: Youssef
authors.forename: H P Vasantha
authors.initials: HP
authors.lastname: Rupasinghe
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D000975:Antioxidants / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D002460:Cell Line; D030024:Curcuma / Q000737:chemistry*; D003474:Curcumin / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D016333:HIV Protease / Q000378:metabolism; D017320:HIV Protease Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D008168:Lung / Q000166:cytology / Q000201:enzymology; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000975:Antioxidants; D017320:HIV Protease Inhibitors; D014442:Monophenol Monooxygenase; D016333:HIV Protease; C514803:p16 protease, Human immunodeficiency virus 1; D003474:Curcumin