Two New Alkaloids from Brachystemma calycinum and Their Inhibitory Effects on Lymphocyte Proliferation

Abstract

Two new alkaloids, brachystemidines F (1) and G (2), were isolated from the roots of Brachystemma calycinum. Their structures were established on the basis of detailed spectroscopic analyses, including extensive NMR and HR-MS techniques. Compound 2, which exhibits an unusual N-hydroxydiazenyl (HO-N=N) moiety, is a potent immunosuppressive agent, as demonstrated by inhibition of mouse T- and B-lymphocyte proliferation, with IC50 values of 6.33 and 5.60 microg/ml, resp.

Pharmacological and Predicted Activities of Natural Azo Compounds

“…Alkaloid brachystemidine G ( 99 ) was isolated from the roots of Brachystemma calycinum . This compound is a potent immunosuppressive agent, as demonstrated by its inhibition of mouse T and B-lymphocyte proliferation, with IC 50 value of 5.6 μg/mL [ 114 ]. The 1,2,4-triazine derivative ( 100 ) was extracted from the seeds of the tropical flowering plant Butea monosperma [ 115 ].…”

Natural Products Containing a Nitrogen–Nitrogen Bond

“…Brachystemidine G ( 41 ) was isolated in 2007 from the roots of Brachystemma calycinum , a plant with widespread use in traditional medicine . Brachystemidine G ( 41 ) is essentially a nitrosoamide but exists as its N -hydroxydiazenyl tautomer.…”

“…Brachystemidine G ( 41 ) is essentially a nitrosoamide but exists as its N -hydroxydiazenyl tautomer. The configuration of 41 could not be elucidated due to insufficient material . Brachystemidine G inhibited the proliferation of B- and T-lymphocytes from Balb/c mice …”

“…The configuration of 41 could not be elucidated due to insufficient material . Brachystemidine G inhibited the proliferation of B- and T-lymphocytes from Balb/c mice …”

Bioactive Compounds from the Aerial Parts of Brachystemma calycinum and Structural Revision of an Octacyclopeptide

“…It is a Chinese folk medicine used to treat rheumatoid arthritis, limb numbness, impotence, and gonorrhea . Previous studies showed that it contains alkaloids and cyclic peptides. − An extract of the whole plant was recently found to be able to reduce disease symptoms and the development of cartilagenous lesions in experimental dog osteoarthritis by inhibiting protease-activated receptor 2 . Inflammatory and immune processes are implicated in rheumatism, and it may be possible to isolate anti-inflammatory or immunoregulatory compounds from B. calycinum that may be useful in the treatment of DN.…”