The active medicinal constituents in Hypericum perforatum, used to treat depression and skin irritation, include flavonoids and xanthones. The carbon skeletons of these compounds are formed by chalcone synthase (CHS) and benzophenone synthase (BPS), respectively. Polyclonal antisera were raised against the polyketide synthases from Hypericum androsaemum and their IgG fractions were isolated. Immunoblotting and immunotitration were used to test the IgGs for crossreactivity and monospecificity in H. perforatum leaf protein extract. Immunofluorescence localization revealed that both CHS and BPS are located in the mesophyll. The maximum fluorescence levels were observed in approx. 0.5 and 1 cm long leaves, respectively. The fluorescence intensity observed for CHS significantly exceeded that for BPS. Using histochemical staining, flavonoids were detected in the mesophyll, indicating that the sites of biosynthesis and accumulation coincide. Our results help understand the biosynthesis and underlying regulation of active H. perforatum constituents.
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http://dx.doi.org/10.3389/fpls.2016.00921 | DOI Listing |
Molecules
May 2021
Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand.
The synthesis of natural products by is a challenging alternative method of environmentally friendly minimization of hazardous waste. Here, we establish a recombinant capable of transforming sodium benzoate into 2,4,6-trihydroxybenzophenone (2,4,6-TriHB), the intermediate of benzophenones and xanthones derivatives, based on the coexpression of benzoate-CoA ligase from (BadA) and benzophenone synthase from (GmBPS). It was found that the engineered accepted benzoate as the leading substrate for the formation of benzoyl CoA by the function of BadA and subsequently condensed, with the endogenous malonyl CoA by the catalytic function of BPS, into 2,4,6-TriHB.
View Article and Find Full Text PDFActa Crystallogr F Struct Biol Commun
December 2020
Life Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu 30076, Taiwan.
Benzophenone synthase (BPS) catalyzes the production of 2,4,6-trihydroxybenzophenone via the condensation of benzoyl-CoA and three units of malonyl-CoA. The biosynthetic pathway proceeds with the formation of the prenylated xanthone α-mangostin from 2,4,6-trihydroxybenzophenone. Structural elucidation was performed to gain a better understanding of the structural basis of the function of Garcinia mangostana L.
View Article and Find Full Text PDFNew Phytol
February 2018
Institute of Pharmaceutical Biology, Technische Universität Braunschweig, Mendelssohnstraße 1, 38106, Braunschweig, Germany.
Xanthones are specialized metabolites with antimicrobial properties, which accumulate in roots of Hypericum perforatum. This medicinal plant provides widely taken remedies for depressive episodes and skin disorders. Owing to the array of pharmacological activities, xanthone derivatives attract attention for drug design.
View Article and Find Full Text PDFActa Crystallogr D Struct Biol
December 2017
Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
Biphenyl synthase and benzophenone synthase constitute an evolutionarily distinct clade of type III polyketide synthases (PKSs) that use benzoic acid-derived substrates to produce defense metabolites in plants. The use of benzoyl-CoA as an endogenous substrate is unusual for type III PKSs. Moreover, sequence analyses indicate that the residues responsible for the functional diversification of type III PKSs are mutated in benzoic acid-specific type III PKSs.
View Article and Find Full Text PDFFront Plant Sci
July 2016
Institute of Pharmaceutical Biology, Technische Universität Braunschweig Braunschweig, Germany.
The active medicinal constituents in Hypericum perforatum, used to treat depression and skin irritation, include flavonoids and xanthones. The carbon skeletons of these compounds are formed by chalcone synthase (CHS) and benzophenone synthase (BPS), respectively. Polyclonal antisera were raised against the polyketide synthases from Hypericum androsaemum and their IgG fractions were isolated.
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