title: Papaya seed represents a rich source of biologically active isothiocyanate.
abstract: In the present study, papaya (Carica papaya) seed and edible pulp were carefully separated and then the contents of benzyl isothiocyanate and the corresponding glucosinolate (benzyl glucosinolate, glucotropaeolin) quantified in each part. The papaya seed with myrosinase inactivation contained >1 mmol of benzyl glucosinolate in 100 g of fresh seed. This content is equivalent to that of Karami daikon (the hottest Japanese white radish) or that of cress. The papaya seed extract also showed a very high activity of myrosinase and, without myrosinase inactivation, produced 460 micromol of benzyl isothiocyanate in 100 g of seed. In contrast, papaya pulp contained an undetectable amount of benzyl glucosinolate and showed no significant myrosinase activity. The n-hexane extract of the papaya seed homogenate was highly effective in inhibiting superoxide generation and apoptosis induction in HL-60 cells, the activities of which are comparable to those of authentic benzyl isothiocyanate.
authors.affiliation: Department of Biofunctional Chemistry, Division of Bioscience, Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan. yossan@cc.oakayama-u.ac.jp
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Motoko
authors.initials: M
authors.lastname: Yoshimoto
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Murata
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Shimoishi
authors.forename: Yumi
authors.initials: Y
authors.lastname: Asai
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Park
authors.forename: Kenji
authors.initials: K
authors.lastname: Sato
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Nakamura
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification* / Q000494:pharmacology; D029441:Carica / Q000737:chemistry* / Q000201:enzymology; D053938:DNA Fragmentation / Q000187:drug effects; D005961:Glucosinolates / Q000302:isolation & purification / Q000494:pharmacology; D006026:Glycoside Hydrolases / Q000378:metabolism; D018922:HL-60 Cells; D006801:Humans; D017879:Isothiocyanates / Q000302:isolation & purification* / Q000494:pharmacology; D010936:Plant Extracts / Q000302:isolation & purification* / Q000494:pharmacology; D012639:Seeds / Q000737:chemistry / Q000201:enzymology
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D005961:Glucosinolates; D017879:Isothiocyanates; D010936:Plant Extracts; C031403:benzyl isothiocyanate; D006026:Glycoside Hydrolases; C022739:thioglucosidase