A novel sodium N-fatty acyl amino acid (SFAAA) surfactant was synthesized using pupa oil and pupa protein hydrolysates (PPH) from a waste product of the silk industry. The aliphatic acids from pupa oil were modified into N-fatty acyl chlorides by thionyl chloride (SOCl2). SFAAA was synthesized using acyl chlorides and PPH. GC-MS analysis showed fatty acids from pupa oil consist mainly of unsaturated linolenic and linoleic acids and saturated palmitic and stearic acids. SFAAA had a low critical micelle concentration, great efficiency in lowering surface tension and strong adsorption at an air/water interface. SFAAA had a high emulsifying power, as well as a high foaming power. The emulsifying power of PPH and SFAAA in an oil/water emulsion was better with ethyl acetate as the oil phase compared to n-hexane. The environment-friendly surfactant made entirely from silkworm pupae could promote sustainable development of the silk industry.

In this study, we used branches Ramulus mori from cultivated mulberry Husang-32 (Morus multicaulis Perry) as the experimental material and anhydrous ethanol as the extraction solution to obtain the crude extract from the branch bark. The ethanolic extract was successively purified through a macroporous resin, Sephadex LH-20, and semipreparative reversed-phase high-performance liquid chromatography (RP-HPLC). The high-purity monomer was identified as morusin by HPLC with diode array detection (HPLC-DAD) and its UV spectrum. The contents of morusin exhibited almost no difference between the root and branch bark in Husang-32, and morusin was not detected in the leaves. Morusin is able to inhibit the tumor growth of transplanted H22 hepatocarcinoma in mice and has no side effects. The fluorescence quantitative real-time PCR (qRT-PCR) results indicate that morusin has a marked inhibitory effect on liver cancer cells through a mechanism that may be related increases in the expression of p53, Survivin, CyclinB1, and Caspase-3 and a decrease in NF-κ B gene expression. The influence of this compound is more apparent in the Caspase-3 and the NF-κ B genes.

In this study, three amino acid mixtures recovered from silk industry waste were reacted with lauryl chloride to synthesize three sodium laurel N‐amino acid surfactants. The three types of anionic surfactants are referred to as silk fibroin surfactant, silk sericin surfactant, and silkworm pupae surfactant. All three surfactants showed good surface properties. To evaluate biological safety, we added these three surfactants to the normal diet of mice for 8 weeks. Blood indices, blood lipid, antioxidant capacity (GSH‐PX, MDA, T‐AOC, and T‐SOD), and lipid metabolism key enzyme mRNA (PPAR‐γ, SREBP, FASN, and C/EBP‐α) levels in the liver were measured. No evident histopathological changes were found in the liver and kidney. The results showed no significant difference in their indexes between the surfactant‐fed and normal diet‐fed mice. Thus, the three amino acid surfactants are biologically safe and can be used in daily chemical cleaning products. These surfactants will not only help to reduce wastage of resources and damage to the environment, but also yield economic benefits to the silk industry in the future.