Herbal Drug Quality and Phytochemical Composition of Hypericum perforatum L. Affected by Ash Yellows Phytoplasma Infection

• Published in: Journal of agricultural and food chemistry 2005-02, Vol.53 (4), p.964-968
• Main Authors: Bruni, Renato, Pellati, Federica, Bellardi, Maria Grazia, Benvenuti, Stefania, Paltrinieri, Samanta, Bertaccini, Assunta, Bianchi, Alberto
• Format: Article
• Language: English
• Subjects: Aroma and flavouring agent industries; Ash yellows phytoplasma; Biological and medical sciences; chemical constituents of plants; Chromatography, High Pressure Liquid; crop quality; essential oils; flavonoids; Food industries; Fundamental and applied biological sciences. Psychology; herbal medicines; hypericin; Hypericum - chemistry; Hypericum - microbiology; Hypericum perforatum; medicinal plants; Oils, Volatile - analysis; Phytoplasma; phytoplasmal diseases; Plant Diseases - microbiology; plant extracts; Plant Extracts - chemistry; Plants, Medicinal - chemistry; Quality Control
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf0487654

Qualitative/quantitative phytochemical variations were observed in dried flowering tops of cultivated Hypericum perforatum L. cv. Zorzi infected by phytoplasmas of the “ash yellows” class, identified by direct and nested polymerase chain reaction (PCR); this is the first report of ribosomial group 16SrVII phytoplasmas in St. John's Wort. Methanolic extracts of healthy and infected plants were separated by reversed phase high-performance liquid chromatography to quantify naphthodianthrones and flavonoids, while essential oils were analyzed by means of gas chromatography (GC)−GC/MS. The affected plants exhibited decreased amounts of rutin (1.96 ± 0.23 vs 4.96 ± 0.02 mg/g), hyperoside (2.38 ± 0.21 vs 3.04 ± 0.05 mg/g), isoquercitrin (1.47 ± 0.04 vs 3.50 ± 0.08 mg/g), amentoflavone (0.12 ± 0.01 vs 0.39 ± 0.02 mg/g), and pseudohypericin (1.41 ± 0.23 vs 2.29 ± 0.07 mg/g), whereas the chlorogenic acid content was doubled (1.56 ± 0.11 vs 0.77 ± 0.02 mg/g). Hypericin, quercitrin, and quercetin contents were not severely affected. The essential oil yield was drastically reduced in infected material (0.11 vs 0.75% in healthy material) and revealed an increased abundance of sesquiterpenes (β-caryophyllene, δ-elemene, and germacrene D, in particular) and a matching decrease in monoterpene hydrocarbons and aliphatics. The consequences that the phytopathological condition of cultivated H. perforatum plants has on the commercial quality, market value, and therapeutic efficacy are outlined. Keywords: Phytoplasma disease; Hypericum perforatum; cultivation; hypericins; flavonoids; essential oil