The esterifications of 9-（hydroxyimino）-4-methyl-8,9-dihydrofuro[2,3-h]chromen-2-one （4） with acid chlorides afforded normal oxime-esters 3a-e in 35-78% yields in presence of excessive 4-dimethylaminopyridine as t...The esterifications of 9-（hydroxyimino）-4-methyl-8,9-dihydrofuro[2,3-h]chromen-2-one （4） with acid chlorides afforded normal oxime-esters 3a-e in 35-78% yields in presence of excessive 4-dimethylaminopyridine as the acid scavenger, whereas the reactions gave unexpected 8-substituted products N-（8-chloro-4-methyl-2-oxo-2H-furo-[2,3-h]chromen-9-yl）amides （5a-c） and 4-methyl-2,9-dioxo-8,9-dihydro-2H-furo[2,3-h]chromen-8-ylcarboxyloates （6d-e） by using excessive acid chlorides. The structures of 10 new compounds were determined by 1H NMR, 13C NMR, MS and HRMS, and the possible mechanism for the formation of unexpected products 5a--c and 6d-e was also proposed.展开更多
The effect of meta-Topolin (mT) was assessed to develop a reliable protocol for efficient plant regeneration of safflower (Carthamus tinctorius L.) cv. NARI-H-15. For micropropagation, 7 - 9 days old shoot-tip explant...The effect of meta-Topolin (mT) was assessed to develop a reliable protocol for efficient plant regeneration of safflower (Carthamus tinctorius L.) cv. NARI-H-15. For micropropagation, 7 - 9 days old shoot-tip explants cultured on MS basal medium supplemented with 3.0 mg/L meta-Topolin (mT) + 0.5 mg/L CPPU showed 97.7% adventitious shoot formation (42.4 shootlets) than node after 45 days of culture. For organogenesis, the seedling explants of immature leaf cultured on 1.5 mg/L CPPU or 1.5 mg/L NAA fortified medium produced high amount of callus than cotyledon and stem calli after 60 days of culture. However, MS basal medium fortified with 4.0 mg/L mT + 1.5 mg/L CPPU was found beneficial to stimulate 100% organogenic response (74.7 shootlets) from immature leaf calli than cotyledon and stem derived calli after 45 days of culture. The healthy plantlets obtained from micropropagation and organogenesis process cultured on 1/4 MS basal salts, 1.5% sucrose (w/v) and 0.8% agar (w/v) medium supplemented with NAA (1.5 mg/L) and mT (0.1 mg/L) produced maximum of 96% (12.8 rootlets) and 84% (7.3 rootlets) adventitious rooting, respectively than mT and CPPU tested medium. However, maximum of 67% and 42% survival rate was noticed when in vitro raised plants from micropropagation and organogenesis were hardened in pots containing soil mix and maintained under green house condition. This optimized regeneration protocol might be helpful in regeneration of new genotypes and cultivars of safflower to improve agronomic traits through in vitro selection process and Agrobacterium-mediated genetic transformation system.展开更多
基金grants from the National Natural Science Foundation of China (No.20272010 and 20672022)
文摘The esterifications of 9-（hydroxyimino）-4-methyl-8,9-dihydrofuro[2,3-h]chromen-2-one （4） with acid chlorides afforded normal oxime-esters 3a-e in 35-78% yields in presence of excessive 4-dimethylaminopyridine as the acid scavenger, whereas the reactions gave unexpected 8-substituted products N-（8-chloro-4-methyl-2-oxo-2H-furo-[2,3-h]chromen-9-yl）amides （5a-c） and 4-methyl-2,9-dioxo-8,9-dihydro-2H-furo[2,3-h]chromen-8-ylcarboxyloates （6d-e） by using excessive acid chlorides. The structures of 10 new compounds were determined by 1H NMR, 13C NMR, MS and HRMS, and the possible mechanism for the formation of unexpected products 5a--c and 6d-e was also proposed.
文摘The effect of meta-Topolin (mT) was assessed to develop a reliable protocol for efficient plant regeneration of safflower (Carthamus tinctorius L.) cv. NARI-H-15. For micropropagation, 7 - 9 days old shoot-tip explants cultured on MS basal medium supplemented with 3.0 mg/L meta-Topolin (mT) + 0.5 mg/L CPPU showed 97.7% adventitious shoot formation (42.4 shootlets) than node after 45 days of culture. For organogenesis, the seedling explants of immature leaf cultured on 1.5 mg/L CPPU or 1.5 mg/L NAA fortified medium produced high amount of callus than cotyledon and stem calli after 60 days of culture. However, MS basal medium fortified with 4.0 mg/L mT + 1.5 mg/L CPPU was found beneficial to stimulate 100% organogenic response (74.7 shootlets) from immature leaf calli than cotyledon and stem derived calli after 45 days of culture. The healthy plantlets obtained from micropropagation and organogenesis process cultured on 1/4 MS basal salts, 1.5% sucrose (w/v) and 0.8% agar (w/v) medium supplemented with NAA (1.5 mg/L) and mT (0.1 mg/L) produced maximum of 96% (12.8 rootlets) and 84% (7.3 rootlets) adventitious rooting, respectively than mT and CPPU tested medium. However, maximum of 67% and 42% survival rate was noticed when in vitro raised plants from micropropagation and organogenesis were hardened in pots containing soil mix and maintained under green house condition. This optimized regeneration protocol might be helpful in regeneration of new genotypes and cultivars of safflower to improve agronomic traits through in vitro selection process and Agrobacterium-mediated genetic transformation system.
