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7-[(2,2-Dimethyl)propyl]-1-methyl xanthine (CAS 155006-67-0, MX2/120) is a new potent antibronchospastic agent with negligible side effects. The synthesis involves the alkylation of 3-benzyl-1-methyl xanthine with neopentyl bromide followed by removal of the benzyl protecting group. Main physico-chemical properties were determined using NMR, MS, IR, UV spectra and X-ray crystal structure. A quantitative determination of substances related to MX2/120 and of residual solvents by means of HPLC and GC, respectively, is described. MX2/120 is safely stored at room temperature for a long time.

Physico-chemical properties, i.e. elemental analysis, spectra (NMR, MS, IR, UV), X-ray crystal structure, solubilities, partition coefficient, melting point, HPLC, GC, and data about purity and stability of 1,3-dimethyl-7-isobutyl xanthine (isbufylline, TE/06, CAS 90162-60-0), a new drug with antibronchospastic properties, are reported.

Resolution of the optical isomers of the alpha-adrenoceptor antagonist IP-66 (1-[2-ethoxy-2-(3'-pyridyl)ethyl]-4-(2'-methoxy-phenyl)piperazine) and its intermediate IP-30 (1-[2-hydroxy-2-(3'-pyridyl)ethyl]-4- (2'-methoxy-phenyl)piperazine have been carried out. Optical purity was assayed by high-pressure liquid chromatography. The antagonistic potencies of racemic mixtures and stereoisomers toward phenylephrine- and norepinephrine-induced contraction in isolated rat aortic strips have been compared. (+)-IP-66 and (+)-IP-30 were resp. 363 and 170 times more potent than respective (-) isomers in eliciting competitive alpha 1-adrenoceptor blockade. Similarly IP-66 (+) or (+/-) were extremely more effective than the (-) isomer in antagonizing norepinephrine-induced pressor responses in pithed rat.

An investigation was carried out to ascertain whether erythro- and threo-alpha-methyl-dihydroxy-phenyl-serine were able of depleting cerebral and peripheral norepinephrine (NE) through their metabolization to alpha-mNE. The results show that the alpha-methyl-aminoacids were decarboxylated only at the periphery and that the threo-form caused depletion in cardiac NE. In any case, both isomers were unable to cross the blood-brain barrier leaving the cerebral NE unaffected. Consequently the use of alpha-mDOPS as alternative tool to alpha-mDOPA in the therapy for hypertension seems unlikely to occur. The results also provide evidence for differences in the pharmacokinetics of the two isomers.