The development of simple, practical and inexpensive catalysis systems using natural materials is one of the main goals of pharmaceutical chemistry as well as green chemistry. Owing to the ability of easy separation of nanocatalyst, those goals could be approached by applying heterogeneous bionanocatalyst in combination with magnetic nanoparticles. Starch is one of the most abundant natural polymers; therefore, preparing bionanocatalyst from starch is very valuable as starch is largely available and inexpensive. An ecologically benign and efficacious heterogeneous nanocatalyst was prepared based on a biopolymer, and its attributes and morphology were specified by using Fourier transform infrared spectra, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), thermal analysis and vibrating sample magnetometer measurements; followed by studying catalytic behaviour of bionanocomposite in a multicomponent reaction to synthesize of 4H-pyran derivatives. 4H-pyran is extremely valuable in pharmaceutical chemistry, and the development of methods for synthesis of different derivatives of 4H-pyran is momentous. Revealing environmentally benign nature, mild condition, easy work-up, low cost and non-toxicity are some of the advantages of this protocol. Besides, the bionanocomposite was recovered using an external magnetic bar and could be re-used at least six times with no further decrease in its catalytic activity.

使用天然材料开发简单、实用且廉价的催化系统是药物化学和绿色化学的主要目标之一。由于纳米催化剂易于分离的能力，这些目标可以通过应用异质生物纳米催化剂与磁性纳米粒子的结合来实现。淀粉是最丰富的天然聚合物之一；因此，由淀粉制备生物纳米催化剂非常有价值，因为淀粉大量可用且廉价。以生物聚合物为基础制备了一种生态良性且有效的多相纳米催化剂，并通过傅里叶变换红外光谱、扫描电子显微镜（SEM）、能量色散X射线光谱（EDX）、X射线衍射等手段确定了其属性和形貌。 (XRD)、热分析和振动样品磁力计测量；随后研究了生物纳米复合材料在合成 4H-吡喃衍生物的多组分反应中的催化行为。 4H-吡喃在药物化学中极具价值，开发4H-吡喃不同衍生物的合成方法具有重要意义。该方案的一些优点是环境友好、条件温和、易于处理、成本低和无毒。此外，使用外部磁棒回收生物纳米复合材料，并且可以重复使用至少六次，而其催化活性不会进一步降低。