Azima tetracantha L. (needle bush; bee
sting bush; Salvadoraceae) is used as a food and for various
herbal medicines in Africa, India, and Madagascar, but there is very little information on the secondary metabolites in this species. High concentrations of N-methoxy-3-indolylmethyl-glucosinolate, a common
glucosinolate of Brassica crops such as Brussels sprouts and broccoli, were found in the roots and seeds of A. tetracantha. Lower concentrations were detected in the stems and young leaves. The roots also contained another
indole glucosinolate that was provisionally identified, from MS data and comparison with
indole glucosinolate standards, as N-hydroxy-3-indolymethyl-glucosinolate. The roots, stems, and leaves contained neoascorbigen (the condensation product of N-methoxy-
indole-3-
carbinol and
ascorbic acid). The seeds of A. tetracantha contained a
complex mixture of 26
flavonoids predominantly as
glycosides and acyl-
glycosides, with traces of aglycones. The core aglycones of these
flavonoids were identified as
quercetin,
isorhamnetin (3'-O-methylquercetin),
rhamnetin (7-O-methylquercetin), and
rhamnazin (7, 3'-di-O-methylquercetin). No
flavonoids or
anthocyanins were detected in other tissues, and
procyanidins were undetectable. The dimeric
piperidine alkaloids azimine, azcarpine, and
carpaine were found in all tissues of A. tetracantha.