title: Two new C-benzylated dihydrochalcone derivatives from the leaves of Melodorum siamensis.
abstract: Two new C-benzylated dihydrochalcone derivatives, 4,2',4'-trihydroxy-6'-methoxy-3'(2''-hydroxybenzyl)dihydrochalcone (1) and 2',4'-dihydroxy-4,6'-dimethoxy-3'(2''-hydroxybenzyl)dihydrochalcone (2), along with six known flavonoid derivatives (3-8), a known dihydrochalcone dimer (9), three known aromatic esters (10-12), and one known aromatic amide (13), were isolated from the leaves of Melodorum siamensis. The structures of the compounds were elucidated by spectroscopic analysis, mainly 1D and 2D NMR techniques (1H, 13C, COSY, HMQC, and HMBC), as well as by comparison with literature data. The isolated compounds with a sufficient amount for biological assays were evaluated for their antimalarial, antimycobactirial, and cytotoxic activities. Compounds 1, 2, and 13 exhibited strong cytotoxicity against human tumor cell lines KB and NCI-H187, with IC50 values in the range of 0.66-7.16 µg/mL.
authors.affiliation: Laboratory of Natural Products Chemistry, Faculty of Science and Technology, Phuket Rajabhat University, Muang, Phuket, Thailand. umaprawat@pkru.ac.th
authors.forename: Uma
authors.initials: U
authors.lastname: Prawat
authors.forename: Orapan
authors.initials: O
authors.lastname: Chairerk
authors.forename: Unreuthai
authors.initials: U
authors.lastname: Phupornprasert
authors.forename: Abdul-Wahab
authors.initials: AW
authors.lastname: Salae
authors.forename: Pittaya
authors.initials: P
authors.lastname: Tuntiwachwuttikul
mesh_terms: D029061:Annonaceae / Q000737:chemistry*; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000962:Antimalarials / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001593:Benzyl Compounds / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D045744:Cell Line, Tumor; D047188:Chalcones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D003603:Cytotoxins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry
chemical_list: C581886:2',4'-dihydroxy-4,6'-dimethoxy-3'(2''-hydroxybenzyl)dihydrochalcone; C581885:4,2',4'-trihydroxy-6'-methoxy-3'(2''-hydroxybenzyl)dihydrochalcone; D000900:Anti-Bacterial Agents; D000962:Antimalarials; D000970:Antineoplastic Agents; D001593:Benzyl Compounds; D047188:Chalcones; D003603:Cytotoxins