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In the synthesis of N-alkylaminoalkanethiosulfuric acids, there exists the possibility of forming two products in the last step of the synthesis. In the case of the seven acids synthesized in this laboratory from styrene oxide and primary aliphatic amines, the common spectroscopic methods were inadequate for distinguishing which of the two isomers was obtained. Carbon-13 chemical shift calculations employing the ACD/CNMR program were helpful, but not conclusive for identifying the products. The use of HMQC, HMBC and TOCSY techniques permitted the identification of the products as the 2-(N-alkylamino)-1-phenyl-1-ethanethiosulfuric acids.

Several novel bioactive components isolated from Chinese medicinal plants will be presented. These include novel maytansinoid tumor, inhibitors, some new ent-kaurane and rosane diterpenoids from Mallotus anomalus Meer et Chun (Euphorbiaceae), as well asnovel insecticide, stemona alkaloids from Stemona parviflora C. H. Wright (Stemonaceae). Both are native plants of Hainan island, Chine. 2D NMR techniques such as mono and hetero-COSY, NOESY, COLOC as well as H-NMR line broadening effect were utilized for structure elucidation. The separation techniques, struture elucidations and bioassay results will be reported.