Zhong-n Jia

Four new terpenoids from the roots of Ligularia narynensis

Four new oplopane and guaiane type sesquiterpenoids (1–3), and a monoterpenoid (4) together with three known monoterpenoids (5–7), have been isolated from the roots of Ligularia narynensis. The structures of 1–4 were elucidated as 3β,4-diacetoxy-8α-(2-methylbutyryloxy)-9α-(4-methylsenecioyloxy)-11α,12-epoxyoplop-10 (14)-ene (1), 3β,4-diacetoxy-9α-(4-acetoxy-4-methylsenecioyloxy)-2β,8α-di (2-methylbutyryloxy)-11α,12-epoxyoplop-10 (14)-ene (2), 2α-hydroxy-1βH,7αH,10αH-guai-4,11 (12)-dien-3-one (3) and 1α,2β,3α,6α-tetrahydroxy-p-menthane (4) by spectroscopic methods. 1 and 2 were evaluated for their in vitro cytotoxic activity against cultured SMMC-7721 (human hepatoma), L02 (human hepatocyte), and HL-60 (human promyelocytic leukaemia) cell lines.

Fast repair of DNA radicals in the earliest stage of carcinogenesis suppresses hallmarks of cancer

Genomic instability is a characteristic of most cancers and could be directly caused by DNA damage. DNA repair maintains genomic integrity, reducing the onset of cancer. A distinct DNA fast repair process, synonymous fast repair, is initiated and finished in a microsecond time scale, enormously faster by approximately 9 orders than enzymatic repair, and thus eradicates the headstream of DNA damage, DNA radicals exclusively, in the earliest stage of carcinogenesis. The known enzymatic repair cannot repair DNA radicals and mutation, but fast repair can. Therefore, the fast repair mechanism is a defence in the front line in fighting carcinogenesis. If there was no fast repair, certainly much more DNA steady damage would accumulate and would lead to mutation and cancer with high risk. Almost all the tested phytophenols with fast repair activity, except one, are able to suppress the hallmarks of cancer, such as morphological normalization, redifferentiation, decrease of cancer growth and transplanting rate, inhibition of telomerase, metastasis and angiogenesisin vitro and in vivo, reducing cancer incidence and mortality rate in animals.