The Synthesis of Neobavaisoflavone and Related Compounds

Abstract

The condensation of 7-benzoyloxy-4′-hydroxyisoflavone with 2-methyl-3-buten-2-ol gave 7-benzoyloxy-4′-hydroxy-3′-(3-methyl-2-butenyl)isoflavone. The hydrolysis of the alkylated isoflavone with dilute alkali afforded neobavaisoflavone [7,4′-dihydroxy-3′-(3-methyl-2-butenyl)isoflavone], which was then converted into isoneobavaisoflavone on heating with formic acid. 7-Benzyloxy-4′-hydroxyisoflavone was condensed with 2-methyl-3-buten-2-ol to give a chroman derivative, which was then converted into isoneobavaisoflavone by hydrolysis. 3′-(3-Methyl-2-butenyl)-5,7,4′-trihydroxyisoflavone was also synthesized from 7-benzoyloxy-5,4′-dihydroxyisoflavone in a similar manner.

Plant Antimutagenic Agents, 2. Flavonoids

“…[M]+ to be 322.1200 (caled for C20H18O4, 322.1205). A literature search showed that several prenylated flavones or isoflavones had the above formula: e.g., licoflavone A (6-C-prenyl-7,4'-dihydroxyflavone) (11), 6-C-prenylchrysin (12), and neobavaisoflavone [5] (13). That the isolated compound was indeed 5 was evident from the mp 187-191°and the ir, uv, and 'H-nmr spectra which were in accord with the literature dNitrofluorene.…”

“…'isolated at Research Triangle Institute. (13). The isoflavone nature of 5 was readily apparent from the 'H-nmr spectra, particularly the C-2 proton which appeared as a singlet at 8.26.…”

Isolation and Characterization of New Anti-HIV and Cytotoxic Leads from Plants, Marine, and Microbial Organisms

“…A conventional battery of NMR experiments, including COSY, HMQC, and HMBC, was performed to confirm the gross structure of compound 18 as shown. Compound 18 differs from the known compound neobavaisoflavone (19) 30 by the presence of an additional hydroxyl group at position C-2′ and reduction of the ∆ 2 olefin; thus, we have named the new compound 2,3-dihydro-2′-hydroxyneobavaisoflavanone (18).…”

Ferroptosis inhibitory constituents from the fruits of Cullen corylifolium

“…All the isolates 1-20 were identified as isopsoralen (1) (Kim et al 2009), psoralen (2) (Kim, Lee, Park and Shim 2009), psoralidin (3) (Oh et al 2010), coumestrol (4) (Al-Maharik and Botting 2004), 3'-methoxycoumestrol (5) (Gong et al2010), isobavachalcone; corylifolinin (6) (Oh et al 2010;Pistelli et al 1996), 4′-O-methylbavachalcone (7) (Oh et al 2010), isobavachromene (8) (Xue-Hui et al 2012), bavachromene ( 9) (Bajwa et al 1972), bavachinin (10) (Oh et al 2010), bavachin (11) (Xu et al 2018), paratocarpin K ( 12) (Hano et al 1995), neobavaisoflavone (13) (Nakayama et al 1978;Xiao et al 2010), corylifol A ( 14) (Yin et al 2004), 8-geranyl daidzein (15) (Kumano et al 2008), 8-prenyldaidzein (16) (IINUMA et al 1992, corylifol C (17) (Yin et al 2004), bakuchiol (18) (Kim et al 2009), 3-hydroxybakuchiol (19) (Labbé et al 1996) and 12-hydroxyisobakuchiol (20) (Labbé et al 1996).…”