Abstract A series of novel 3, 4-dihydro-3-methyl-2(1H)-quinazolinone derivatives with substituted amine moieties (1-13) and substituted aldehyde (S) were designed and synthesized by a reflux condensation reaction in the presence of an acid catalyst to get N-Mannich bases. Mannich bases were evaluated pharmacologically for their antioxidant, α-amylase enzyme inhibition, antimicrobial, cell cytotoxicity and anti-inflammatory activities. Most of the compounds exhibited potent activities against these bioassays. Among them, SH1 and SH13 showed potent antioxidant activity against DPPH free radical at IC50 of 9.94±0.16 µg/mL and 11.68±0.32 µg/mL, respectively. SH7, SH10 and SH13 showed significant results in TAC and TRP antioxidant assays, comparable to that of ascorbic acid. SH2 and SH3 showed potent activity in inhibiting α-amylase enzyme at IC50 of 10.17±0.23 µg/mL and 9.48±0.17 µg/mL, respectively, when compared with acarbose (13.52±0.19 µg/mL). SH7 was the most active against gram-positive and gram-negative bacterial strains, SH13 being the most potent against P.aeruginosa by inhibiting its growth up to 80% (MIC= 11.11 µg/mL). SH4, SH5 and SH6 exhibited significant activity against some fungal strains. Among the thirteen synthesized compounds (SH1-SH13), four were screened out based on the results of brine shrimp lethality assay (LD50) and cell cytotoxicity assay (IC50), to determine their anti-cancer potential against Hep-G2 cells. The study was conducted for 24, 48, and 72 h. SH12 showed potent results at IC50 of 6.48 µM at 72 h when compared with cisplatin (2.56 µM). An in vitro nitric oxide (NO) assay was performed to shortlist compounds for in vivo anti-inflammatory assay. Among shortlisted compounds, SH13 exhibited potent anti-inflammatory activity by decreasing the paw thickness to the maximum compared to the standard, acetylsalicylic acid (ASA).

中文翻译：

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新型 3, 4-Dihydro-3-methyl-2(1H)-quinazolinone 衍生物的一锅多组分合成及其作为潜在抗氧化剂、酶抑制剂、抗微生物剂、细胞毒剂和抗炎剂的生物学评价

摘要 通过回流缩合反应，设计并合成了一系列具有取代胺基 (1-13) 和取代醛 (S) 的新型 3, 4-二氢-3-甲基-2(1H)-喹唑啉酮衍生物。酸催化剂得到N-曼尼希碱。对曼尼希碱的抗氧化、α-淀粉酶抑制、抗菌、细胞毒性和抗炎活性进行了药理学评估。大多数化合物对这些生物测定表现出有效的活性。其中，SH1和SH13对DPPH自由基显示出有效的抗氧化活性，IC50分别为9.94±0.16 µg/mL和11.68±0.32 µg/mL。SH7、SH10 和 SH13 在 TAC 和 TRP 抗氧化试验中显示出显着的结果，与抗坏血酸的结果相当。与阿卡波糖 (13.52±0.19 µg/mL) 相比，SH2 和 SH3 显示出有效的抑制 α-淀粉酶的活性，IC50 分别为 10.17±0.23 µg/mL 和 9.48±0.17 µg/mL。SH7 对革兰氏阳性和革兰氏阴性细菌菌株最有效，SH13 对铜绿假单胞菌最有效，抑制其生长高达 80% (MIC = 11.11 µg/mL)。SH4、SH5 和 SH6 对一些真菌菌株表现出显着的活性。在合成的13种化合物（SH1-SH13）中，根据盐水虾致死率（LD50）和细胞毒性试验（IC50）的结果筛选出4种，以确定它们对Hep-G2细胞的抗癌潜力。该研究进行了 24、48 和 72 小时。与顺铂 (2.56 µM) 相比，SH12 在 72 小时时的 IC50 为 6.48 µM，显示出有效的结果。进行了体外一氧化氮 (NO) 测定以筛选出用于体内抗炎测定的化合物。在入围的化合物中，与标准的乙酰水杨酸 (ASA) 相比，SH13 通过将爪子厚度降低到最大值而表现出有效的抗炎活性。