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Shellac is a physically refined form of lac resin, a natural biopolymer of animal origin obtained from tiny insects feeding on the sap of specific host trees. Shellac, in its basic form, is a polyester macromolecule composed of inter and intra esters of polyhydroxy aliphatic and sesquiterpene acids. It has been used in several industries for ages due to its exceptional properties such as film-forming, adhering, bonding, thermoplasticity, water-resistance and easy solubility in spirit and aqueous alkali solvents. From the beginning of the 21st century, due to increasing demand for natural products, a paradigm shift in the scope and applications of shellac has been witnessed, especially in green electronics, 3D printing, stealth technology, intelligent sensors, food and pharmaceutical industries. Shellac offers enormous potential for greener technologies as a natural and environmentally friendly material. This review provides an insight into the lac in detail, covering various forms of the lac, structure, properties, different applications of shellac and its future potential. This article would benefit the researchers involved in shellac research and others looking for natural and greener alternatives to synthetic polymers in various applications. [Display omitted] • Shellac is a natural resin obtained from tiny insects from Kerria species. • Owing to its unique properties, shellac has been used in several industries. • Various forms, structure, properties and applications of shellac are discussed. • Scope of shellac for the use in modern applications is highlighted. • Shellac, as a raw material offers a huge potential to the greener technologies. [ABSTRACT FROM AUTHOR]

Kerria lacca is commercially harnessed for lac resin, dye and wax. This study is an attempt towards identifying the possible pathway and genes involved in the biosynthesis of the lac dye. It is proposed that lac insects employ polyketide pathway catalysed by polyketide synthase to produce laccaic acid D, a common precursor molecule for the biosynthesis of other lac dye constituents. Post-PKS tailoring enzymes are also involved in the alteration of polyketide chains. Thirteen related genes were identified and sequenced in this study. [ABSTRACT FROM AUTHOR]

Chemical communication between the lac insect associated products and the lac predators were evaluated under the laboratory condition. Semiochemicals were identified and comparative analysis carried out for different stages of lac insect and its associated products. Six major compounds viz. decane, dodecane, tetradecane, heptadecane, eicosane and octacosyl acetate constituted 78%, 79% and 85% in lac insect whole body, lac resin and lac wax extracts, respectively. Electroantennograms (EAGs) responses of adult male and female of lac insect predator, Eublemma amabilis to different lac insect extracts and its associated products (LIAPs) revealed higher responses of predator male and female to lac insect whole body extract (-0.731 and -1.182 mV, respectively) than resin, wax, crawler and lac insect female extracts. Among both the sexes of another lac insect predator Pseudohypatopa pulverea, EAGs response was significantly higher in female towards lac insect whole body (-1.059 mV) than resin, wax, adult female and crawler extracts than P. pulverea males. Both E. amabilis and P. pulverea exhibited high level of sensitivity to lac insect whole body extracts with different concentrations viz., 1000 ppm, 5000 ppm and 10000 ppm than identified semiochemicals viz., Decane, Hexadecane, Nonadecane, Eicosane and hexane. Orientation response of E. amabillis and P. pulverea through "Y" tube olfactometer revealed higher attraction of P. pulverea than E. amabillis. [ABSTRACT FROM AUTHOR]

• A single method was developed for the extraction and purification of aleuritic acid from seedlac. • Microwave treatments enabled the complete hydrolysis of lac resin in < 30 min. • Removal of impurities before acid treatment of sodium aleuritate is crucial for the production of pure aleuritic acid. • The developed process produces aleuritic acid ten times faster and with>40 % higher yield with a purity of >98 %. Aleuritic acid is one of the high-value constituents of lac resin, which has a massive demand in the perfumery industry for synthesizing macrocyclic lactones. The commercial aleuritic acid extraction process is lengthy, inefficient, and produces low-quality aleuritic acid, which necessitates repeated purification using toxic chemicals, bleaching agents, organic solvents, and activated carbon to obtain the desired quality aleuritic acid. This study developed a single process for extraction and purification of aleuritic acid involving microwave-assisted hydrolyzing of the seed lac and removing impurities of lac resin through condensation and alkali heat treatment. The novel process has reduced the overall extraction time from 15 days to 1.5–2 days and increases the yield from 35 to 40 % to 85–86 % and purity from 70 to 86 % to > 98 % in a single process without the use of toxic chemicals, bleaching agents, or organic solvents, unlike the commercially available process. HPLC, FT-IR, DSC, and FESEM techniques were employed to characterize and evaluate the quality of the extracted aleuritic acid. The developed process is highly efficient and cost-effective and offers scalable and fast extraction while requiring minimal chemicals, labor, and energy compared to alternative processes. Moreover, it exhibits greater environmental sustainability. [Display omitted] [ABSTRACT FROM AUTHOR]

Lac, a natural resinous substance having profound economic importance, is a secretion of Lac insect Kerria chinensis (Hemiptera: Kerridae). Lac is widely cultivated in different states of India on several host plants. North eastern region particularly Assam is one of the biodiversity hotspots with approximately 4000 species of plants but exploitation of these natural flora for commercial production of lac is very limited. This present study aims to explore the suitability of eight native plants viz., Flemingia semialata Roxb., Flemingia strobilifera (L.) W.T.Aiton, Indigofera teysmannii L., Ficus religiosa L., Zizyphus mauritiana Lam., Litchi chinensis Sonn., Hibiscus rosa-sinensis L. and Cajanus cajan L. as hosts of lac insect. Both field and laboratory experiments were carried out to study the productivity linked parameters and life cycle of the lac insect on the respective plants. Biochemical constituents of the host plants were also studied to find out their role in resin production. Among the eight native plants, F. semialata showed highest productivity of broodlac (0.30 kg) and longest life cycle duration (164.5 ± 2.5 days) in winter lac cultivation. Phenol content of the bark registered a significant positive correlation with the production of lac whereas both alkaloid and flavonoid were found non- significant with the production of lac. [ABSTRACT FROM AUTHOR]

The differential proteins associated with plasma membrane of spermatozoa are less known, identification of which shall help overcome limitations of currently used methods of sperm sexing, considered as a high priority for livestock sector of many countries. This study has reported plasma membrane proteomics of unsorted spermatozoa and differential expression of plasma membrane‐associated proteins between X‐ and Y‐chromosome bearing spermatozoa of indicus cattle (Bos indicus). Isolation of plasma membrane fraction using percoll gradient, relatively a rapid method, from bovine spermatozoa has been reported to enrich isolation of plasma membrane proteins. Significant enrichment for plasma membrane‐associated proteins was observed in plasma membrane fraction (p <.05) as compared to the total cell lysate using LC‐MS/MS. Furthermore, these experiments were conducted in flow cytometry sorted, sexed‐semen samples. Thirteen proteins were identified as differentially abundant between X‐ and Y‐sorted spermatozoa. Among these, two proteins were downregulated in Y‐sorted spermatozoa compared to the X‐sorted spermatozoa (p <.05), while four and seven proteins could be noted in X‐ and Y‐sorted spermatozoa, respectively. Proteins that are presumed to support sperm capacitation and sperm migration velocity were found to be abundant in Y‐sorted spermatozoa while those associated with structural molecule activity were identified as abundant in X‐sorted spermatozoa in the present study. Our study provides better insight into the plasma membrane proteomics of spermatozoa of indicus cattle and furnishes data that might aid in design and development of alternate and open technology for sex‐sorting of semen. [ABSTRACT FROM AUTHOR]

Objective: Certain anthraquinone compounds are effectively used for treatment of cancer. The present study describes the inhibitory activity of lac dye, a mixture of polyhydroxy anthraquinone compounds (Laccaic acid A, B, C, D and E), produced by the Indian lac insect, Kerria lacca (Kerr).Materials and Methods: In vitro testing for anticancer activity of lac dye was done at four concentrations (10, 20, 40, 80 μg/ml) on ten human malignant cell lines including six human leukemia cell lines, U973, Raji, K562, Jurkat, MOLT 4 and HL60 using SRB assay.Results and Conclusion: Both crimson and yellow lac dye inhibits proliferation of Human leukemia cell lines, Raji, U937, K562, HL60 and Jurkat, therefore can be considered as a potential anticancer agent for leukemia. [ABSTRACT FROM AUTHOR]