| synthesis and antitumour activity of the primin (2-methoxy-6-n-pentyl-1,4-benzoquinone) and analogues. | cancer is a serious worldwide health threat, killing almost seven million people per year. quinones are an important class of antitumour agents that are activated by tumour hypoxia. primin (2-methoxy-6-n-pentyl-1,4-benzo-quinone), a naturally-occurring product obtained from primula obconica (primulaceae) has shown antimicrobial and antitumour properties. the synthesis of the primin to obtain 3-, 5- or 6-alkyl substituted derivatives has been previously attempted seeking antitumour activity. the ... | 2007 | 17627574 |
| plant regeneration from cell suspension-derived protoplasts of primula malacoides and primula obconica. | protoplasts were isolated from cell suspension cultures of primula malacoides cv. 'lovely tokyo' and p. obconica cv. 'aalsmeer giant white'. p. obconica protoplasts were embedded in 0.1% (w/v) gellan gum-solidified discs comprising ms medium supplemented with 3 mg/l of 2,4-d or picloram, 0.1 mg/l of zeatin, 0.2 m glucose and 0.2 m mannitol, and surrounded by a liquid medium of the same composition except for the addition of 0.1% (w/v) activated charcoal. the protoplasts formed visible colonies, ... | 2001 | 11337079 |
| structure-activity relationships in allergic contact dermatitis (i). studies on the influence of side-chain length with derivatives of primin. | primin (2-methoxy-6-pentyl-1,4-benzoquinone) is a naturally-occurring strong sensitizer from primula obconica (primulacease). to determine the effect of side-chain length on sensitizing potency, 15 analogues with linear side chains from c1 to c15 and 4 c6-analogues with branched side chains were prepared synthetically and devoted to experimental sensitization in guinea pigs. the results showed an increase of the sensitizing capacity with increasing length of the alkyl side chain from c1 to c10, ... | 1995 | 7493455 |
| primula obconica, a carrier of tobacco necrosis viruses. | | 1947 | 20247595 |
| [allergic contact dermatitis caused by garlic, primula, frullania and compositae]. | as a complementary study to a previous work (14) in which we examined 43 cases of contact dermatitis to plants, we have taken a closer look at the provocative cases which made up 76% of that study - allium (garlic) (11 cases), primula (8), frullania (8) and compositae (6). the clinical methodology, preparation of extracts and execution of the skin tests were identical to those described in the previous study (14). patients with sensitivity to frullania and compositae were submitted to standard s ... | 1985 | 4083225 |
| the sensitizing capacity of naturally occurring quinones. experimental studies in guinea pigs. ii. benzoquinones. | experimental studies on the sensitizing capacity of naturally occurring benzoquinones, isolated from plants and woods have been carried out in guinea pigs of the pirbright white strain. seven compounds were available: primin, three dalbergiones, mansonia quinone (mansonone a), 2,6-dimethoxybenzoquinone and rapanone. with five of these substances (primin, mansonone a, three dalbergiones) guinea pigs could be sensitized. primin, the allergen of primula obconica hance (primrose) proved to be the mo ... | 1979 | 464645 |