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Okra (Abelmoschus esculentus (L.) Moench) pod storage is challenging due to its high water content and tendency to lignify. Sodium hydrosulfide (NaHS) served as an H2S donor in this investigation. Compared with the control group, the group treated with 0.5 mmol/L NaHS solution effectively maintained the appearance quality, and its weight loss was only 6.21% at 20 days. The H2S treatment not only preserved tissue nutrients but also significantly enhanced catalase (CAT), ascorbic acid peroxidase (APX), and superoxide dismutase (SOD) activities while decreasing oxidant damage. In addition, H2S slowed down lignin synthesis by inhibiting the activities of key enzymes such as phenylalanine ammonialyase (PAL), cinnamate 4-hydroxylase (C4H), and cinnamyl alcohol dehydrogenase (CAD) in the lignin biosynthesis pathway. Transcriptome analysis revealed that H2S affects 34 genes in the phenylpropanoid biosynthesis pathway, such as AePAL, Ae4CL1, AeCCOAOMT1, AePOD, etc., which inhibit lignin synthesis of okra pods. All in all, moderate H2S can improve postharvest quality and extend the shelf-life of okra pods by enhancing antioxidant capacity and delaying lignification; the results will provide an overview of its application in the preservation of okra pods. [ABSTRACT FROM AUTHOR]

• The reaction conditions were systematically investigated and optimized using a statistical experimental design. • 2,3-epoxy-pinane yield was higher than 90% in the optimized conditions. • Reusability extended up to six runs with 85% 2,3-epoxy-pinane yield. • The reason for the decreased activity of Mn/SAPO-34 catalyst was investigated. Aerobic epoxidation of bio-based olefins is an important topic in green and sustainable chemistry. In this work, an Mn/SAPO-34 catalyst was prepared by ion-exchange method for the epoxidation of α-pinene in presence of molecular oxygen and iso-butyraldehyde. The factors influencing α-pinene epoxidation were determined and the conditions were optimized by response surface methodology (RSM). The result showed that the sensitive conditions were co-reductant amount, Mn loading amount and catalyst amount. After optimization, α-pinene was completely converted and a 90.47% yield of 2,3-epoxy-pinane was obtained. The result showed that the catalyst was reusable for six cycles. In addition, the support and catalysts were characterized by XRD, BET, ICP-OES, SEM-EDS, TEM and XPS, and it was confirmed the reasons for the degradation of the catalyst activity were the damage of crystal particles, the decrease in specific surface area of catalyst, the loss of active components and the irreversible oxidation of Mn2+ [Display omitted] [ABSTRACT FROM AUTHOR]