本文是一篇药学论文，笔者通过本实验，丰富了日本血吸虫的化学成分，并在一定程度上阐明了其细胞毒活性，为今后进一步深入研究和合理开发利用提供了科学的理论依据。
I. Introduction
Tumor, also known as a malignant cancer, is a class of diseases involvingabnormal cell differentiation and proliferation, uncontrolled growth and spread toother organs of the body. Generally, signs and symptoms of tumor depend on itslocation, type, size, and extent of its effects to the organ or tissues. With a wide rangeof different signs and symptoms that can evident in different ways. However, generalsymptoms of cancers are: presence of an unusual lump, persistent cough or hoarseness,change in bowel habits, unexplained weight loss, unexplained pain, and unexplainednight sweat, fever, etc.
In 2020, the number of lung tumor cases was the second highest after breastcancer, which took up 11.4 percent of the total. Other common tumors includedcolorectal (10 percent), prostate tumor (7.3 percent) and stomach tumor (5.6 percent)[1]. There are more than 200 types of cancer that can affect more than 60 organsaccording to the Cancer Research Organization (UK) [2]. Currently, treatments formalignant tumors include surgery, radiotherapy, and chemotherapy, among whichchemotherapy has been deemed effective but accompanied with defects including lowefficacy, poor prognosis, serious side effects, and drug resistance, which limit theirtherapeutic efficiency in clinical application[3]. Over 30% of tumor deaths could betreated by modifying or avoiding its key risk factors. Various tumor treatmentapproaches are: surgery, chemotherapy, hormone therapy, immunotherapy,photodynamic therapy (PDT), radiotherapy, and gene therapy. The choice oftreatment approaches depends on tumor stage, type, and available resources. In 2015,The research by Prof. Tu Youyou on artemisinin gained her as one of the winners ofthe Nobel Prize in Physiology, which aroused profound impetus in the investigationof traditional Chinese medicine [4]. Abundant natural plant resources in China, thenatural products of Chinese herbal medicine play an important role in cancerprevention[5]. Hartwell, in his review of plants used against cancer, lists more than3000 plant species that have reportedly been used in the treatment of tumors [6]. Morethan 60% of clinical drugs are derived from natural products or their derivatives,including paclitaxel, vinblastine, vincristine, podophyllotoxin, camptothecin,colchicine, etc [7, 8]. Natural products as the main sources of new drugs and play majorroles in the treatment of cancer based on their favorable safety and efficacy profiles.
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II. Materials and Methods
1. General experimental procedures
The NMR spectra (1H and 13C-NMR) were obtained using a Bruker AV 300 MHzand a Bruker AV 500 MHz spectrometer (Barker, Fallanden, Switzerland). CDCl3,CD3OD and pyridine-d5 were used as solvent. Column chromatography wasperformed using silica gel (200-300 mesh, Branch of Qingdao Haiyang Chemical Co.,Ltd., Qindao, P. R. China) and reversed-phase silica gel was accomplished with LiChroprep RP-18 gel (40–63 μM, Merck KGaA , Darmstadt, Germany). SephadexLH-20 was purchased from Merck KGaA in Germany. Thin-layer chromatography(TLC) was performed with Silica gel GF254 glass plates (20 x 20 cm, Branch ofQingdao Haiyang Chemical Co., Ltd.) and RP-18 F254s (25 glass plates 20 x 20 cm)was purchased from Merck KGaA in Germany. All chemical reagents were analyticalgraded and were used with further purification. The lung cancer cell line (A549),cervical cancer cell line (HeL a), and hepatoma cell line (SK-Hep1) were obtainedfrom the Cell Bank of Chinese Academy of Sciences (Shanghai, China).
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2. Plant materials
The whole plants of Chimaphila japonica Miq. were collected from theChangbai Mountain area, Jilin Province, China, in July 2018 and identified by Prof.Hui-zi Lv (School of Pharmaceutical Sciences, Yanbian University, China). A voucherspecimen (20180702-XDC) was deposited at the Department of Pharmacognosy,School of Pharmaceutical Sciences, and Yanbian University.
The air-dried whole plant of C. japonica (3.3 kg) was extracted with 90%ethanol (3 × 40 L) at room temperature. The crude extract (627.3 g) was suspendedwith distilled water and successively partitioned into petroleum ether (PE, 3 × 1.4 L),ethyl acetate (EtOAc, 3 × 1.4 L), and n-butyl alcohol (n-BuOH, 3 × 1.4 L)sequentially, to give PE, EtOAc, n-BuOH, and aqueous fractions, respectively.
药学论文怎么写
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III. Results and Discussion......................... 16
1. Structure elucidation of compounds 1 – 18........................16
2. Cytotoxic activity evaluation of 1 – 18 compounds inhibition............................ 34
2.1 cytotoxic activity of compounds 1 – 18 against A549...................................34
2.2 cytotoxic activity of compounds 1 – 18 against HeL a...................................35
IV. Conclusion.....................................37
III. Results and discussion
1. Structure elucidation of compounds 1-18
药学论文参考
Compound 1 was obtained as white amorphous. Molecular formula as C30H50Oand its molecular weight 426.72; In the 1H-NMR spectrum exibits one olefinic protonδ 5.55 (1H, dd, J = 8.1, 3.0 Hz, H-15), one hydroxy group at 3.30 – 3.15 (1H, m, H-3)and eight methyl groups at δ 1.11 (3H, s, Me-27), 0.99 (3H, s, Me-23), 0.97 (3H, s,Me-29), 0.95 (3H, s, Me-24), 0.93(3H, s, Me-30), 0.93 (3H, s, Me-26), 0.84 (3H, s,Me-25) and 0.82 (3H, s, Me-28). Therefore, in the13C-NMR spectrum showed a totalof 30 carbon signals, two olefinic carbon signals at δ 158.1 (C-14), 116.8 (C-15), onehydroxy group signal at δ 79.1(C-3) and eight methyl signals at δ 33.4 (C-29), 29.9(C-28), 28.0 (C-23), 28.9 (C-26), 25.9 (C-27), 21.3 (C-30), 15.4 (C-24) and 15.1(C-25). Consequently, based on the above data, compound 1 was identified astaraxerol which was confirmed by comparison of spectral data with those of literature.
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IV. Conclusion
In the screening for cytotoxic activities from a medicinal plant in ChangbaiMountain area, eighteen compounds (1-18) from the EtOAc fraction of Chimaphilajaponica Miq were isolated; by normal phase silica gel column chromatography,RP-18 column chromatography, Sephadex LH-20 column chromatography andrecrystallization. The compounds structures were elucidated on the basis ofspectroscopic studies, and their cytotoxicity were evaluated.
1. The isolated compounds 1-18 were identified as 3β-taraxerol (1), chimaphilin(2), β-sitosterol (3), 6-hydroxy 2, 7-dimethyl-1, 4-naphthaquinone (4), pyrolin (5),ursolic acid (6), eupatoric acid (7), α-amaryin (8), β-amaryin (9), 3β,27-dihydroxy-lup-12 ene (10), oleanolic acid (11), kaempferol (12), quercetin (13),kaempferol-3-O-α-L-5''-acetyl- arabinofuranoside (14), gallic acid (15), corosolic acid(16), japonica acid (17) and α-amyrenone (18). The obtained compounds includednine triterpenes, three flavonoids, two quinolones, two phenolic, one steroid and onefatty acid, which indicated that triterpenes were the main chemical constituents of theEtOAc fraction of C. japonica. Among them, compounds 3, 5, 7, 9 ~ 15, 17 and 18were isolated for the first time from this plant.
2. The anti-tumor activity of the isolated compounds from the EtOAc layer of C.japonic against A549, HeL a and SK-Hep1 cells by MTT method showed thatcompounds 2 ~ 5, 7, 10, 11 and 16 inhibited the growth of A549, compounds 3, 5, 10,11 and 16 inhibited the growth of HeL a, and compounds 1 ~ 3, 5 ~ 8, 10, 11 and 16inhibited the growth of SK-Hep1 at 30 μM concentration.
3. In conclusion, compounds 2, 3, 5, 10, 11 and 16 have significant inhibitoryeffects on the three cancer cells. The inhibition of these human cancer cells valuesexceeded 50%, respectively, which could be a potential candidate for tumor treatment.In human lung cancer cells (A549), compounds 2, 5 and 11 exhibited particularlysignificant cytotoxic activities, with IC50 values of 1.25 ± 1.14, 1.84 ± 1.23 and 2.64 ±1.08 μM. Compounds 2 and 4 showed significant cytotoxic activities in humancervical cancer cells (HeL a), with IC50 values of 1.21 ± 0.47 and 1.96 ± 0.22 μM,respectively. Compounds 2, 4 and 5 showed significant cytotoxic activities in humanhepatoma cells (SK-Hep1), with IC50 values of 2.56 ± 0.63, 1.52 ± 0.32 and 1.18 ±0.74 μM, respectively.
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