奇楠沉香中2-(2-苯乙基)色酮的GC-MS分析鉴定

采用乙醚浸提法提取奇楠沉香样品,并应用气相色谱-质谱联用(GC-MS)技术分析测定其中的化学成分及相对含量,鉴定了11个化合物。同时采用柱色谱技术对该乙醚提取物进行分离纯化得到单体化合物1~6,其结构通过核磁共振等波谱技术鉴定为2-（2-苯乙基）色酮类化合物。通过质谱比对,将GC-MS分析中未能鉴定的5个含量较高的成分分别鉴定为化合物2~6。样品中2-（2-苯乙基）色酮类化合物的相对含量达到63.62％,表明奇楠沉香富含2-（2-苯乙基）色酮类化合物。探讨了2-（2-苯乙基）色酮类化合物的质谱裂解规律,有     

GC-MS分析4种奇楠沉香中致香的倍半萜和2-(2-苯乙基)色酮类成分

采用乙醚浸提法提取了4种奇楠沉香样品(海南产白奇楠、海南产紫奇楠、海南产绿奇楠和越南产绿奇楠),4个样品的得率分别为:20.3%、27.6%、48.0%、40.2%。应用气相色谱-质谱联用(GC-MS)技术分析测定4个样品乙醚提取物的化学成分及相对含量,从4种奇楠沉香中共鉴定了37个化合物,其中倍半萜类化合物共20个,据报道有香味描述的有7个;2-(2-苯乙基)色酮类化合物11个,在海南产白奇楠、海南产紫奇楠、海南产绿奇楠和越南产绿奇楠乙醚提取物中相对含量分别达到74.55%、95.59%、93.90%、89.57%,其中,化合物2-(2-苯乙基)色酮和化合物2-[2-(4-甲氧基苯)乙基]色酮在这4种奇楠中相对含量之和分别达到了66.47%、82.09%、84.71%、71.98%。结果表明,奇楠沉香乙醚提取物中含少量的多种骨架类型的芳香倍半萜,富含2-(2-苯乙基)色酮类化合物,特别是化合物2-(2-苯乙基)色酮与2-[2-(4-甲氧基苯)乙基]色酮。     

国产人工打洞沉香中一个新的2-(2-苯乙基)色酮二聚体

为进一步研究国产人工打洞法所结沉香中的化学成分,本研究采用硅胶柱色谱、Sephadex LH-20、半制备高效液相等色谱方法从其乙酸乙酯萃取物中分离纯化得到2个单体化合物.根据核磁共振(NMR)、质谱(MS)等波谱数据分别鉴定为2-(2-苯乙基)色酮二聚体(+)-3′,3′′′-dihydroxy-4′,4′′′-di...     

基于UPLC-Q-TOF-MS/MS的沉香2-(2-苯乙基)色酮聚合物成分分析

为了明确沉香（Aquilaria spp.）药材中2-(2-苯乙基)色酮聚合物（PPECs）组分及其结构,本研究采用超高效液相色谱-串联四级杆-飞行时间质谱法（UPLC-Q-TOF-MS/MS）采集沉香样品一级与二级质谱图,对PPECs的质谱裂解途径进行分析,对沉香药材中PPECs组分进行筛查与结构确证。共鉴定出PPECs组分55个,根据结构特征,55个组分分属于3种结构类型,即2-(2-苯乙基)色酮二聚物（DPECs）、2-(2-苯乙基)色酮三聚物（TPECs）和萜类-2-(2-苯乙基)色酮二聚物（SPECs）。鉴定的全部组分包括44个DPECs、3个TPECs和8个SPECs,其中9个DPECs、1个TPECs和1个SPECs首次在沉香中被发现;其次,沉香PPECs的部分组分具有2～4个同分异构体。综上,沉香药材中PPECs组分及其同分异构体丰富,且DPECs类型的组分在总PPECs中所占比例最高（80%）。该研究结果可为沉香药效物质基础研究及开发利用提供参考。     

整树结香法所产沉香的GC-MS分析

采用整树结香法诱导健康白木香树结香,并根据树体受伤后木材的颜色形态特征将木材分为腐烂层、沉香层和白木层,运用气相色谱-质谱联用(GC-MS)技术分别对三层的乙醚提取物进行了分析。结果表明,不同层化学成分的种类和相对含量上有明显差异。沉香层与腐烂层的2-(2-苯乙基)色酮类成分总相对含量都很高,腐烂层的色酮类成分相对含量(70.25%)高于沉香层(60.08%),但沉香层的色酮种类(14个)比腐烂层(10个)多;倍半萜类成分在沉香层和腐烂层中的相对含量均较低,沉香层的倍半萜类成分相对含量(5.75%)略高于腐烂层(3.75%),而腐烂层的倍半萜个数(11个)略多于沉香层(8个)。白木层则以甾体类化合物为主,没有检出色酮类和倍半萜类成分。     

一种国外野生沉香的生物活性和化学成分研究

研究一种国外野生沉香乙醚提取物的生物活性并分析其化学成分,为国外野生沉香的进一步研究和开发利用提供一定的基础。采用乙醚浸提法提取沉香,对提取物分别用 MTT 法、Ellman 法、pNPG 法和贝曼漏斗法进行细胞毒、乙酰胆碱酯酶抑制、α-葡萄糖苷酶抑制和杀全齿复活线虫活性测试,利用 GC-MS 分析提取物化学成分。结果表明,该提取物对 5 株人体肿瘤细胞、乙酰胆碱酯酶、α-葡萄糖苷酶和全齿复活线虫均表现出一定的生物活性。GC-MS 检测鉴定了其中的 26 个化合物,相对含量为 57.39%,包括 23 个倍半萜类成分,相对含量为 56.72%,1 个 2-(2-苯乙基)色酮类成分,相对含量为 0.35%。本次对此种国外野生沉香的生物活性和化学成分研究,发现沉香乙醚提取物具有杀线虫的活性,为更好地开发沉香的药用价值提供了一定的科学依据。     

一种国外野生沉香的生物活性和化学成分研究

研究一种国外野生沉香乙醚提取物的生物活性并分析其化学成分,为国外野生沉香的进一步研究和开发利用 提供一定的基础。采用乙醚浸提法提取沉香,对提取物分别用 MTT 法、Ellman 法、pNPG 法和贝曼漏斗法进行细胞毒、 乙酰胆碱酯酶抑制、α-葡萄糖苷酶抑制和杀全齿复活线虫活性测试,利用 GC-MS 分析提取物化学成分。结果表明,该 提取物对 5 株人体肿瘤细胞、乙酰胆碱酯酶、α-葡萄糖苷酶和全齿复活线虫均表现出一定的生物活性。GC-MS 检测鉴 定了其中的 26 个化合物,相对含量为 57.39%,包括 23 个倍半萜类成分,相对含量为 56.72%,1 个 2-(2-苯乙基)色酮 类成分,相对含量为 0.35%。本次对此种国外野生沉香的生物活性和化学成分研究,发现沉香乙醚提取物具有杀线虫 的活性,为更好地开发沉香的药用价值提供了一定的科学依据。     

气-质联用法测定干槟榔中苯并(α)芘含量

提出一种测定干槟榔中痕量苯并(α)芘的方法,试样经氢氧化钾皂化,弗洛里硅土固相柱净化,正已烷二氯甲烷液洗脱,浓缩,用标准加入法和GC-MS(气相色谱-质谱)定量测定。试验证明,测定结果平均回收率达到80%以上,相对标准偏差RSD为0.97%～1.2%,方法线性、精密、准确度均良好,可以满足分析的要求。     

内标校准液相色谱荧光法测定食用油中苯并(a)芘

采用内标苯并（b）屈校正,建立了正相固相净化－反相液相色谱－荧光分光光度法测定食用油中苯并(a)芘的方法。正相Plus Silica固相萃取柱作为净化柱,反相C18柱作为分离柱。以苯并（b）屈作为内标,测定了苯并(a)芘的校正因子。使用本方法,苯并(a)芘在液态食用油和固态食用油中的检出限分别为0.01和0.03μg/kg。苯并(a)芘在不同食用油回收率在83%～108%之间,方法的日内精密度和日间精密度分别小于7.7%和13.2%。     

抗黄曲霉毒素单克隆抗体F(ab')2片段的制备与活性

为剧毒靶标(黄曲霉毒素)绿色分析提供高效抗体,在已有抗黄曲霉毒素杂交瘤细胞株1Cll的基础上,通过小鼠腹水法制备单克隆抗体,经胃蛋白酶酶解,制备F(ab')2片段,发现在优化条件37C、pH4.1柠檬酸缓冲液中酶解4.5h,可高效制备F(ab')2片段.通过酶联免疫吸附法(ELISA)比较了抗体片段与原始抗体的识别活性,发现F(ab')2片段效价达到1∶320000,是原抗体效价的1.5倍;灵敏度(IC50)为8.7pg/mL,保持了原抗体的抗原结合能力.     

Anti-Cancer and Anti-Inflammatory Activities of Three New Chromone Derivatives from the Marine-Derived Penicillium citrinum

Three new and uncommon chromone analogs, epiremisporine F (1), epiremisporine G (2), and epiremisporine H (3), were isolated from marine-origin Penicillium citrinum. Among the isolated compounds, compounds 2–3 remarkably suppressed fMLP-induced superoxide anion generation by human neutrophils, with IC₅₀ values of 31.68 ± 2.53, and 33.52 ± 0.42 μM, respectively. Compound 3 exhibited cytotoxic activities against human colon carcinoma (HT-29) and non-small lung cancer cell (A549) with IC₅₀ values of 21.17 ± 4.89 and 31.43 ± 3.01 μM, respectively, and Western blot assay confirmed that compound 3 obviously induced apoptosis of HT-29 cells, via Bcl-2, Bax, and caspase 3 signaling cascades.     

Preparation and properties of 2-(2-aminoethoxy) ethyl chitosan/cellulose fiber using N-methylmorpholine-N-oxide process

N-methylmorpholine-N-oxide (NMMO) is used widely in the manufacturing of man-made cellulose fibers and functional lyocell fibers due to its environment-friendly advantage. Although chitosan is known as a natural antibacterial polymer it has poor solubility in neutral to basic medium and the antibacterial activity is shown only in acidic medium. Chitosan’s poor solubility in NMMO is the disadvantage for the production of antibacterial lyocell fibers. This paper investigates a more “NMMO soluble” derivative of chitosan, 2-(2-aminoethoxy) ethyl chitosan (AECS). AECS has greatly improved solubility in NMMO hydrate, and stronger antibacterial activity than chitosan. AECS was introduced to modify the lyocell fiber spun in a co-solution of cellulose and AECS in NMMO hydrate. The physical properties and antibacterial activity of the fibers were examined and the results indicated that the modified lyocell fiber, containing more than 2 wt% of AECS, exhibits good antibacterial activity against E. coli and slightly decreased tensile strength compared with unmodified fibers.     

Preparation,COX-2 Inhibition and Anticancer Activity of Sclerotiorin Derivatives

The latest research has indicated that anti-tumor agents with COX-2 inhibitory activity may benefit their anti-tumor efficiency. A series of sclerotiorin derivatives have been synthesized and screened for their cytotoxic activity against human lung cancer cells A549, breast cancer cells MDA-MB-435 using the MTT method. Among them, compounds 3, 7, 12, 13, 15, 17 showed good cytotoxic activity with IC₅₀ values of 6.39, 9.20, 9.76, 7.75, 9.08, and 8.18 μM, respectively. In addition, all compounds were tested in vitro the COX-2 inhibitory activity. The results disclosed compounds 7, 13, 25 and sclerotiorin showed moderate to good COX-2 inhibition with the inhibitory ratios of 58.7%, 51.1%, 66.1% and 56.1%, respectively. Notably, compound 3 displayed a comparable inhibition ratio (70.6%) to the positive control indomethacin (78.9%). Furthermore, molecular docking was used to rationalize the potential of the sclerotiorin derivatives as COX2 inhibitory agents by predicting their binding energy, binding modes and optimal orientation at the active site of the COX-2. Additionally, the structure-activity relationships (SARS) have been addressed.     

Reduction of (E)-2-nonenal and (E,E)-2,4-decadienal during sourdough fermentation

(E)-2-Nonenal and (E,E)-2,4-decadienal are key aroma compounds in wheat bread crumb. The fate of these unsaturated aldehydes in sourdoughs fermented with homo- and heterofermentative lactobacilli or baker's yeast was investigated, and the metabolic pathways in these microorganisms identified. Clear differences were observed between homofermentative lactobacilli, heterofermentative lactobacilli and Saccharomyces cerevisiae. Heterofermentative strains rapidly reduced the concentrations of these aldehydes in dough, whereas S. cerevisiae displayed a lower activity. Lactobacillus sanfranciscensis reduced the aldehydes to the corresponding unsaturated alcohols, whereas S. cerevisiae reduced both the aldehyde moiety and the double bond, resulting in the formation of the corresponding saturated alcohols. S. cerevisiae first reduced the aldehyde moiety and then the double bond. In L. sanfranciscensis, the reduction of aldehydes is coupled to the oxidation of NADH to NAD⁺, which enables this heterofermentative strain to produce additional ATP from glucose. L. sakei, a strain that produces only lactic acid during sourdough fermentation, did not metabolise the unsaturated aldehydes at all. Both L. sakei and S. cerevisiae appeared to enhance aldehyde formation during the first hours of dough fermentation, probably due to the hydrogen peroxide production by these two strains.     

不同(S)-(-)-小蠹烯醇载体诱芯对橡胶小蠹虫的诱捕效果

为了研发基于(S)-(-)-小蠹烯醇诱捕橡胶小蠹虫的安全高效诱捕技术,系统开展了不同(S)-(-)-小蠹烯醇诱芯对橡胶小蠹虫的诱捕效果试验。结果表明,自制的(S)-(-)-小蠹烯醇海绵诱芯和无纺布型诱芯对橡胶小蠹虫的诱捕效果最好,整个试验周期内平均单日单个诱芯诱捕器诱捕虫数分别为69.16头和66.22头,田间诱捕效果先逐渐增加,30 d时达到高峰,而后又逐渐下降,60 d后显著下降,1~60 d的平均单日单个诱芯诱捕器诱捕虫数分别为75.22~120.45头和70.69~112.22头。储藏瓶型诱芯对橡胶小蠹虫也具有良好的诱捕效果,平均单日单个诱芯诱捕器诱捕虫数为24.85头,田间诱捕效果先逐渐增加,至10 d时达到高峰,而后又逐渐下降,至30 d后显著下降,1~30 d的平均单日单个诱芯诱捕器诱捕虫数为48.53~64.66头。上述3种诱芯对严重危害橡胶树的对粒材小蠹和循胸材小蠹的诱捕效果尤为显著,对粒材小蠹和循胸材小蠹的诱捕数量占诱捕害虫总数的百分比分别为48.36%和47.89%、46.89%和40.48%、40.45%和40.24%。1~90 d的淀粉颗粒状缓释型诱芯和环糊精糊状缓释型诱芯对橡胶小蠹虫的诱捕效果无显著性变化,平均单日单个诱芯诱捕器诱捕虫数均在10头以下,诱捕效果差。上述结果表明,自制的(S)-(-)-小蠹烯醇海绵诱芯、无纺布型诱芯和储藏瓶型诱芯均可广泛用于有效绿色监控橡胶小蠹虫,海绵诱芯、无纺布型诱芯的田间有效期为60 d,储藏瓶型诱芯的田间有效期为30 d。     

4-(Phenylsulfanyl) Butan-2-One Attenuates the Inflammatory Response Induced by Amyloid-β Oligomers in Retinal Pigment Epithelium Cells

Age-related macular degeneration (AMD) is a progressive eye disease that causes irreversible impairment of central vision, and effective treatment is not yet available. Extracellular accumulation of amyloid-beta (Aβ) in drusen that lie under the retinal pigment epithelium (RPE) has been reported as one of the early signs of AMD and was found in more than 60% of Alzheimer’s disease (AD) patients. Extracellular deposition of Aβ can induce the expression of inflammatory cytokines such as IL-1β, TNF-α, COX-2, and iNOS in RPE cells. Thus, finding a compound that can effectively reduce the inflammatory response may help the treatment of AMD. In this research, we investigated the anti-inflammatory effect of the coral-derived compound 4-(phenylsulfanyl) butan-2-one (4-PSB-2) on Aβ_1-42 oligomer (oAβ_1-42) added to the human adult retinal pigment epithelial cell line (ARPE-19). Our results demonstrated that 4-PSB-2 can decrease the elevated expressions of TNF-α, COX-2, and iNOS via NF-κB signaling in ARPE-19 cells treated with oAβ_1-42 without causing any cytotoxicity or notable side effects. This study suggests that 4-PSB-2 is a promising drug candidate for attenuation of AMD.