Daniel J. Siebert- Localization of Salvinorin A and Related Compounds in Glandular Trichomes of the...

doi:10.1093/aob/mch089, available online at www.aob.oupjournals.org Localization of Salvinorin A and Related Compounds in Glandular Trichomes of the Psychoactive Sage, Salvi a divinorum DANIEL J. SIEBERT* PO Box 6145, Malibu, CA 90264, USA Recei ved: 9 Ju ne 2003 Retu rned fo r revisi on: 9 Dec ember 2 003 Accep ted: 2 Feb ruar y 2004 d Backgr ound and Aims Salvia divin orum produce s severa l closel y relat ed neocle rodane diterpene s. The most abundant of these, salvinorin A, is responsible for the psychoactive properties of the plant. To determine where these compounds occur in the plant, various organs, tissues and glandular secretions were chemically analysed. A mic ros copic sur vey of the S. divin orum pla nt was per for med to exa mine the variou s types of tri chomes presen t and to determine their distribu tion. d Methods Chemi cal analyses were performed using thin layer chroma tograp hic and histoc hemic al techni ques. Trich omes were exami ned using convention al light microscop y and scanni ng elect ron micro scopy. d Key Results It was found that neoclerodane diterpenes are secreted as components of a resin that accumulates in peltate glandular trichomes, speci®cally in the subcuticular space that exists between the trichome head cells and the cutic le that enclos es them. Four main types of trich omes were observe d: peltate glandular trichomes, shor t-s tal ked capita te gla ndular tri chomes, long-s tal ked capita te gla ndul ar tri chomes and non- gla ndular trichomes. Their morphology and distribution is described. Peltate glandular trichomes were only found on the abaxial surfaces of the leaves, stems, rachises, bracts, pedicles and calyces. This was consistent with chemical analyses, which showed the presence of neoclerodane diterpenes in these organs, but not in parts of the plant where peltate glandular trichomes are absent. d Conclusions Salvinorin A and related compounds are secreted as components of a complex resin that accumulates in the subcuticular space of peltate glandular trichomes. ã 2004 Annals of Botany Company Key words: Salvia divinorum, Labiatae, diviner's sage, salvinorin A, salvinorins, neoclerodane diterpenes, trichomes , thin layer chromatography, histochemistry, morphology. INTRODUCTION Salvia divinorum (Labiatae) is a powerful psychoactive herb (Fig. 1). It is endemic to a relatively small region in the mountainous north-eastern corner of the Mexican state of Oaxaca. The Mazatec Indians that inhabit the area cultivate the plant and use its leaves in medico-religious ceremonies. Whe n ingest ed in the tra dit ional manner , it pro duc es an alter ed state of awareness that is deepl y intro specti ve in nature. Depending on a person's sensitivity and the amount consumed, the effects range from subtle to profound. When the effects are inten se, peopl e often experie nce extra ordin - ary dream-like visions. Mazatec shamans reportedly utilize these visionary states to venture into supernatural realms and to contact divine entities, whose aid they often petition to remedy the complaints of their clients. They also use the herb remedially at sub-visionary doses to treat a variety of conditions. These include arthritis, headache and elimina- tory complaints (Wasson, 1962; Valde Â s et al., 1983). The spe cie s has severa l dis tin cti ve mor pholog ica l cha rac ter istics tha t, taken tog eth er, make it pos sible to ident ify ¯owering specimens with relative ease. A detai led descri pt ion of the morphology and di st ri butio n of it s trich omes is presen ted here. Other aspects of the plant's anatomy have previously been described elsewhere (Epling and Ja Â tiva-M., 1962; Valde Â s, 1983; Reis®eld, 1987, 1993). The psychoactive principle of the plant has been identi- ®ed as the neoclerod ane diter pene salvinori n A (Sie bert, 1994). Its str uct ure (Fig. 2) was cha rac ter ize d by two independent research groups working concurrently (Ortega et al., 1982; Valde Â s, 1983; Valde Â s et al., 1984; Koreeda et al., 199 0). This compou nd has been identi®ed as an extremely potent and highly selective kappa-opioid receptor agonist. Consequently, it has attracted much attention from pha rma col ogi sts. It is the ®rs t nat ura lly occ urr ing, non - nitrogenous, opioid-receptor-subtype-selective agonist dis- cover ed (Roth et al., 2002; Shef ¯e r and Roth, 2003; Chavkin et al., 2004). The potential of salvinorin A as an antidepressant medication is being explored (Hanes, 2001, 2003). The concentration of salvinorin A in leaves at various st ages of deve lopment on an indi vi dual pl ant is of ten remarkabl y consist ent . However, lea ves col lec ted fr om separate plants can vary considerably, even when they are genetically identical. The speci®c growing conditions and environmental factors that in¯uence salvinorin A content have not been identi®ed. In a previous study, quantitative analysis of 20 dry leaf samples, each collected from separate pla nts , showed sal vinorin A con tents tha t ran ged from 0´0 89 to 0´ 37 %, with most samples being close to the total average of 0´245 %. Whol e stem tissue was also analysed, but the amount of salvinorin A detected was too small to accurately quantify. The concentration in the stems Annals of Botany, ã Annals of Botany Company 2004; all rights reserved * For correspon dence. E-mail dsiebert@s agewisdom.org Annals of Botany

Daniel J. Siebert- Localization of Salvinorin A and Related Compounds in Glandular Trichomes of the...

Documents

Transcript of Daniel J. Siebert- Localization of Salvinorin A and Related Compounds in Glandular Trichomes of the...