The lachrymatory principle of Petiveria alliacea Roman Kubec 1 , Seokwon Kim, Rabi A. Musah* Department of Chemistry, State University of New York at Albany, Albany, NY 12222, USA Received 24 September 2002; received in revised form 17 December 2002 Abstract The lachrymatory principle of Petiveria alliacea has been isolated from a fresh homogenate of the root. Its structure and geo- metric configuration have been determined as (Z)-thiobenzaldehyde S-oxide by means of NMR, IR, MALDI-MS and by compar- ison with an authentic compound obtained by synthesis. This unique compound represents only the third naturally occurring sulfine (thiocarbonyl S-oxide) to be reported. Its formation and possible subsequent rearrangements are discussed. Its antibacterial and antifungal activities are also reported. # 2003 Elsevier Science Ltd. All rights reserved. Keywords: Petiveria alliacea; Phytolaccaceae; Lachrymator; Sulfine; Thiobenzaldehyde S-oxide 1. Introduction Petiveria alliacea L. (Phytolaccaceae) is a perennial shrub widely distributed in South and Central America, some areas of Africa and the southeastern United States. It is popularly used in folk medicine for treating a wide variety of disorders. In our previous contributions, we have reported identification of several novel cysteine derivatives, including diastereoisomers of S-benzyl- and S-(2- hydroxyethyl)cysteine sulfoxides (petiveriin A/B and 6- hydroxyethiin A/B, respectively) (Kubec and Musah, 2001; Kubec et al., 2002). We have also isolated four novel thiosulfinates that are enzymatically formed from these amino acids upon disruption of the tissue of P. alliacea. As we proposed, these thiosulfinates can read- ily decompose to yield a variety of breakdown products, including those previously identified in this plant (e.g. dibenzyl sulfides, benzyl 2-hydroxyethyl sulfides, ben- zaldehyde and stilbenes). The present study was stimulated by our sensory observations experienced while working with the plant. Upon disruption of the tissue, an intense alliaceous odor was immediately emitted, causing irritation to nasal and ocular mucosae, leading to a serious nasal discharge and lachrymation, respectively. However, none of the thiosulfinates we isolated in the previous study possesses such a strong odor and all of them are devoid of lachrymatory effects, indicating that another compound is responsible for these properties. Thus, the present paper describes our investigation and identifica- tion of the lachrymatory principle of P. alliacea. 2. Results and discussion A fresh homogenate of the plant was extracted using Et 2 O. The extract was carefully concentrated and ana- lyzed by C-8 HPLC. Along with the three benzyl-con- taining thiosulfinates described in our previous study (Kubec et al., 2002), another component was abun- dantly present in the extract. The compound (1) was subsequently isolated by prep. C-8 HPLC as a yellow, pungent oil, exhibiting very strong lachrymatory properties. The 1 H NMR spectrum of 1 was quite simple, con- taining only signals corresponding to five aromatic pro- tons (3H,  7.40–7.52 ppm and 2H,  8.06–8.11 ppm) together with one singlet with a very downfield chemical shift (1H,  8.34 ppm). 13 C NMR spectroscopy showed the presence of five magnetically non-equivalent carbon 0031-9422/03/$ - see front matter # 2003 Elsevier Science Ltd. All rights reserved. PII: S0031-9422(02)00759-8 Phytochemistry 63 (2003) 37–40 www.elsevier.com/locate/phytochem * Corresponding author. Tel.: +1-518-437-3740; fax: +1-518-437- 3741. E-mail address: musah@csc.albany.edu (R.A. Musah). 1 Current address: Department of Food Chemistry and Analysis, Institute of Chemical Technology, Technicka´ 1905, Prague 6, 166 29, Czech Republic.